@article {6301, title = {Grassland sensitivity to drought is related to functional composition across East Asia and North America}, journal = {Ecology}, year = {In Press}, keywords = {LTER-KNZ}, doi = {10.1002/ecy.4220}, url = {https://esajournals.onlinelibrary.wiley.com/doi/10.1002/ecy.4220}, author = {Song, Lin and Griffin-Nolan, Robert J. and Muraina, Taofeek O. and Chen, Jiaqi and Te, Niwu and Shi, Yuan and Whitney, Kenneth D. and Zhang, Bingchuan and Yu, Qiang and M. D. Smith and Zuo, Xiaoan and Wang, Zhengwen and Alan K. Knapp and Han, Xingguo and S.L Collins and Luo, Wentao} } @phdthesis {6259, title = {Grassland responses to seasonal shifts in water availability}, volume = {PhD Dissertation}, year = {2023}, school = {Colorado State University}, type = {Ph.D. Thesis}, address = {Fort Collins, CO}, keywords = {LTER-KNZ}, doi = {https://api.mountainscholar.org/server/api/core/bitstreams/a7decffd-ba41-4d12-ae8e-19ce83a2ce3f/content}, author = {Hajek, O.L.} } @article {KNZ002029, title = {Global impacts of fertilization and herbivore removal on soil net nitrogen mineralization are modulated by local climate and soil properties}, journal = {Global Change Biology}, volume = {26}, year = {2020}, abstract = {

Soil nitrogen (N) availability is critical for grassland functioning. However, human activities have increased the supply of biologically limiting nutrients, and changed the density and identity of mammalian herbivores. These anthropogenic changes may alter net soil N mineralization (soil net Nmin), that is, the net balance between N mineralization and immobilization, which could severely impact grassland structure and functioning. Yet, to date, little is known about how fertilization and herbivore removal individually, or jointly, affect soil net Nmin across a wide range of grasslands that vary in soil and climatic properties. Here we collected data from 22 grasslands on five continents, all part of a globally replicated experiment, to assess how fertilization and herbivore removal affected potential (laboratory-based) and realized (field-based) soil net Nmin. Herbivore removal in the absence of fertilization did not alter potential and realized soil net Nmin. However, fertilization alone and in combination with herbivore removal consistently increased potential soil net Nmin. Realized soil net Nmin, in contrast, significantly decreased in fertilized plots where herbivores were removed. Treatment effects on potential and realized soil net Nmin were contingent on site-specific soil and climatic properties. Fertilization effects on potential soil net Nmin were larger at sites with higher mean annual precipitation (MAP) and temperature of the wettest quarter (T.q.wet). Reciprocally, realized soil net Nmin declined most strongly with fertilization and herbivore removal at sites with lower MAP and higher T.q.wet. In summary, our findings show that anthropogenic nutrient enrichment, herbivore exclusion and alterations in future climatic conditions can negatively impact soil net Nmin across global grasslands under realistic field conditions. This is an important context-dependent knowledge for grassland management worldwide.

}, keywords = {LTER-KNZ}, doi = {10.1111/gcb.15308}, url = {https://onlinelibrary.wiley.com/doi/full/10.1111/gcb.15308}, author = {Risch, Anita C. and Zimmermann, Stefan and Moser, Barbara and Sch{\"u}tz, Martin and Hagedorn, Frank and Firn, Jennifer and Fay, Philip A. and Adler, Peter B. and Biederman, Lori A. and J. M. Blair and Borer, Elizabeth T. and Broadbent, Arthur A. D. and Brown, Cynthia S. and Cadotte, Marc W. and Caldeira, Maria C. and Davies, Kendi F. and Virgilio, Augustina and Eisenhauer, Nico and Eskelinen, Anu and Knops, Johannes M. H. and MacDougall, Andrew S. and McCulley, Rebecca L. and Melbourne, Brett A. and Moore, Joslin L. and Power, Sally A. and Prober, Suzanne M. and Seabloom, Eric W. and Siebert, Julia and Silveira, Maria L. and Speziale, Karina L. and Stevens, Carly J. and Tognetti, Pedro M. and Virtanen, Risto and Yahdjian, Laura and Ochoa-Hueso, Raul} } @article {KNZ001965, title = {Global change effects on plant communities are magnified by time and the number of global change factors imposed}, journal = {Proceedings of the National Academy of Sciences}, volume = {116}, year = {2019}, pages = {17867-17873}, abstract = {

Global change drivers (GCDs) are expected to alter community structure and consequently, the services that ecosystems provide. Yet, few experimental investigations have examined effects of GCDs on plant community structure across multiple ecosystem types, and those that do exist present conflicting patterns. In an unprecedented global synthesis of over 100 experiments that manipulated factors linked to GCDs, we show that herbaceous plant community responses depend on experimental manipulation length and number of factors manipulated. We found that plant communities are fairly resistant to experimentally manipulated GCDs in the short term (\<10 y). In contrast, long-term (\≥10 y) experiments show increasing community divergence of treatments from control conditions. Surprisingly, these community responses occurred with similar frequency across the GCD types manipulated in our database. However, community responses were more common when 3 or more GCDs were simultaneously manipulated, suggesting the emergence of additive or synergistic effects of multiple drivers, particularly over long time periods. In half of the cases, GCD manipulations caused a difference in community composition without a corresponding species richness difference, indicating that species reordering or replacement is an important mechanism of community responses to GCDs and should be given greater consideration when examining consequences of GCDs for the biodiversity\–ecosystem function relationship. Human activities are currently driving unparalleled global changes worldwide. Our analyses provide the most comprehensive evidence to date that these human activities may have widespread impacts on plant community composition globally, which will increase in frequency over time and be greater in areas where communities face multiple GCDs simultaneously.

}, keywords = {LTER-KNZ}, doi = {10.1073/pnas.1819027116}, url = {https://www.pnas.org/content/early/2019/08/14/1819027116}, author = {Kimberly J. Komatsu and M.L. Avolio and Lemoine, Nathan P. and Isbell, Forest and Grman, Emily and Houseman, Gregory R. and Koerner, Sally E. and Johnson, D.S. and K.R. Wilcox and Juha M. Alatalo and Anderson, J.P. and Aerts, R. and S.G. Baer and Baldwin, Andrew H. and Bates, J. and Beierkuhnlein, C. and Belote, R.T. and John M. Blair and Bloor, J.M.G. and Bohlen, P.J. and Edward W. Bork and Elizabeth H. Boughton and W.D. Bowman and Britton, Andrea J. and Cahill, James F. and Chaneton, Enrique J. and Chiariello, N.R. and Cheng, Jimin. and Scott. L. Collins and Cornelissen, J.H.C. and G. Du and Eskelinen, Anu and Firn, Jennifer and Foster, B. and Gough, L. and Gross, K. and Hallett, L.M. and Han, X. and Harmens, H. and Hovenden, M.J. and Jagerbrand, A. and Jentsch, A. and Kern, Christel and Klanderud, Kari and Alan K. Knapp and Kreyling, Juergen and Li, W. and Luo, Yiqi and McCulley, R.L. and McLaren, Jennie R. and Megonigal, Patrick and J.W. Morgan and Onipchenko, Vladimir and Pennings, S.C. and Prev{\'e}y, J.S. and Price, Jodi N. and P.B. Reich and Robinson, Clare H. and Russell, L.F. and Sala, O.E. and Seabloom, E.W. and M.D. Smith and Soudzilovskaia, Nadejda A. and Souza, Lara and K.N. Suding and Suttle, B.K. and Svejcar, T. and Tilman, David and Tognetti, P. and Turkington, R. and White, S. and Xu, Zhuwen and Yahdjian, L. and Yu, Q. and Zhang, Pengfei and Zhang, Yunhai} } @article {KNZ001933, title = {Global patterns and drivers of ecosystem functioning in rivers and riparian zones}, journal = {Science Advances}, volume = {5}, year = {2019}, pages = {eaav0486}, abstract = {

River ecosystems receive and process vast quantities of terrestrial organic carbon, the fate of which depends strongly on microbial activity. Variation in and controls of processing rates, however, are poorly characterized at the global scale. In response, we used a peer-sourced research network and a highly standardized carbon processing assay to conduct a global-scale field experiment in greater than 1000 river and riparian sites. We found that Earth\’s biomes have distinct carbon processing signatures. Slow processing is evident across latitudes, whereas rapid rates are restricted to lower latitudes. Both the mean rate and variability decline with latitude, suggesting temperature constraints toward the poles and greater roles for other environmental drivers (e.g., nutrient loading) toward the equator. These results and data set the stage for unprecedented \“next-generation biomonitoring\” by establishing baselines to help quantify environmental impacts to the functioning of ecosystems at a global scale.

}, keywords = {LTER-KNZ}, doi = {10.1126/sciadv.aav0486}, url = {http://advances.sciencemag.org/content/5/1/eaav0486}, author = {Tiegs, Scott D. and Costello, David M. and Isken, Mark W. and Woodward, Guy and McIntyre, Peter B. and Gessner, Mark O. and Chauvet, Eric and Griffiths, Natalie A. and Flecker, Alex S. and Acu{\~n}a, Vicenc and Albari{\~n}o, Ricardo and Allen, Daniel C. and Alonso, Cecilia and Andino, Patricio and Arango, Clay and Aroviita, Jukka and Barbosa, Marcus V. M. and Barmuta, Leon A. and Baxter, Colden V. and Bell, Thomas D. C. and Bellinger, Brent and Boyero, Luz and Brown, Lee E. and Bruder, Andreas and Bruesewitz, Denise A. and Burdon, Francis J. and Callisto, Marcos and Canhoto, Cristina and Capps, Krista A. and Castillo, Mar{\'\i}a M. and Clapcott, Joanne and Colas, Fanny and Col{\'o}n-Gaud, Checo and Cornut, Julien and Crespo-P{\'e}rez, Ver{\'o}nica and Cross, Wyatt F. and Culp, Joseph M. and Danger, Michael and Dangles, Olivier and de Eyto, Elvira and Derry, Alison M. and Villanueva, {\'\i}az and Douglas, Michael M. and Elosegi, Arturo and Encalada, Andrea C. and Entrekin, Sally and Espinosa, Rodrigo and Ethaiya, Diana and Ferreira, Ver{\'o}nica and Ferriol, Carmen and Flanagan, Kyla M. and Fleituch, Tadeusz and Follstad Shah, Jennifer J. and Frainer Barbosa, Andr{\'e} and Friberg, Nikolai and Frost, Paul C. and Garcia, Erica A. and Garc{\'\i}a Lago, Liliana and Garc{\'\i}a Soto, Pavel Ernesto and Ghate, Sudeep and Giling, Darren P. and Gilmer, Alan and {\c c}alves, Jos{\'e} Francisco and Gonzales, Rosario Karina and Graca, Manuel A. S. and Grace, Mike and Grossart, Hans-Peter and Guerrold, Francois and Gulis, Vlad and Hepp, Luiz U. and Higgins, Scott and Hishi, Takuo and Huddart, Joseph and Hudson, John and Imberger, Samantha and {\~n}iguez-Armijos, Carlos and Iwata, Tomoya and Janetski, David J. and Jennings, Eleanor and Kirkwood, Andrea E. and Koning, Aaron A. and Kosten, Sarian and Kuehn, Kevin A. and Laudon, Hjalmar and Leavitt, Peter R. and Lemes da Silva, Aurea L. and Leroux, Shawn J. and LeRoy, Carri J. and Lisi, Peter J. and MacKenzie, Richard and Marcarelli, Amy M. and Masese, Frank O. and McKie, Brendan G. and Oliveira Medeiros, Adriana and Meissner, Kristian and Mili{\v s}a, Marko and Mishra, Shailendra and Miyake, Yo and Moerke, Ashley and Mombrikotb, Shorok and Mooney, Rob and Moulton, Tim and Muotka, Timo and Negishi, Junjiro N. and Neres-Lima, Vinicius and Nieminen, Mika L. and Nimptsch, Jorge and Ondruch, Jakub and Paavola, Riku and Pardo, Isabel and Patrick, Christopher J. and Peeters, Edwin T. H. M. and Pozo, Jesus and Pringle, Catherine and Prussian, Aaron and Quenta, Estefania and Quesada, Antonio and Reid, Brian and Richardson, John S. and Rigosi, Anna and Rinc{\'o}n, Jos{\'e} and Risnoveanu, Geta and Robinson, Christopher T. and Rodr{\'\i}guez-Gallego, Lorena and Royer, Todd V. and Rusak, James A. and Santamans, Anna C. and Selmeczy, G{\'e}za B. and Simiyu, Gelas and Skuja, Agnija and Smykla, Jerzy and Sridhar, Kandikere R. and Sponseller, Ryan and Stoler, Aaron and Swan, Christopher M. and Szlag, David and Mello, Franco Teixeira-de and Tonkin, Jonathan D. and Uusheimo, Sari and Veach, Allison M. and Vilbaste, Sirje and Vought, Lena B. M. and Wang, Chiao-Ping and Webster, Jackson R. and Wilson, Paul B. and Woelfl, Stefan and Xenopoulos, Marguerite A. and Yates, Adam G. and Yoshimura, Chihiro and Yule, Catherine M. and Zhang, Yixin X. and Zwart, Jacob A.} } @phdthesis {KNZ001966, title = {Grassland sensitivity to extreme drought: Assessing the role of dominant species physiology and community functional composition}, volume = {PhD Dissertation}, year = {2019}, school = {Colorado State University}, type = {Ph.D. Thesis}, address = {Fort Collins, CO}, keywords = {LTER-KNZ}, url = {https://mountainscholar.org/bitstream/handle/10217/197274/GriffinNolan_colostate_0053A_15495.pdf?sequence=1}, author = {Griffin-Nolan, Robert} } @mastersthesis {KNZ001967, title = {Growing up prairie: Ecological drivers of grassland songbird nestling development}, volume = {MS Thesis}, year = {2019}, school = {Kansas State University}, type = {M.S. Thesis}, address = {Manhattan, KS}, keywords = {LTER-KNZ}, url = {https://krex.k-state.edu/dspace/handle/2097/40070}, author = {Winnicki, Sarah} } @article {KNZ001750, title = {Gene expression differs in codominant prairie grasses under drought}, journal = {Molecular Ecology Resources}, volume = {18}, year = {2018}, pages = {334-346}, abstract = {

Grasslands of the Central US are expected to experience severe droughts and other climate extremes in the future, yet we know little about how these grasses will respond in terms of gene expression. We compared gene expression in Andropogon gerardii and Sorghastrum nutans, two closely related co-dominant C4 grasses responsible for the majority of ecosystem function, using RNA-seq. We compared Trinity assemblies within each species to determine annotated functions of transcripts responding to drought. Subsequently, we compared homologous annotated gene-groups across the two species using cross-species meta-level analysis and functional clustering based on key terms. The majority of variation was found between species, as opposed to between drought and watered treatments. However, there is evidence for differential responses; Andropogon allocated gene expression differently compared to Sorghastrum, suggesting Andropogon focuses on stress alleviation (such as oxygen radical scavenging) rather than prevention. In contrast, Sorghastrum may employ a drought avoidance strategy by modulating osmotic response, especially with hormonal regulation. We found Sorghastrum tended to be more sensitive within 10 key gene-groups related to stress, abscisic acid, and trichomes, suggesting gene expression may mechanistically parallel sensitivity at the physiological level. Our findings corroborate phenotypic and physiological differences in the field, and may help explain the phenotypic mechanisms of these two species in the tallgrass prairie community under future drought scenarios.

}, keywords = {LTER-KNZ}, doi = {10.1111/1755-0998.12733}, url = {https://onlinelibrary.wiley.com/doi/full/10.1111/1755-0998.12733}, author = {Hoffman, Ava M. and M.D. Smith} } @article {KNZ001911, title = {Genetic and environmental influences on stomates of big bluestem (Andropogon gerardii)}, journal = {Environmental and Experimental Botany}, volume = {155}, year = {2018}, pages = {477 - 487}, abstract = {

Big bluestem (Andropogon gerardii) is a dominant C4 prairie grass that has wide distribution and several genetically distinct ecotypes. Many of the ecotypic adaptations are related to water availability in the native environment. Stomates facilitate photosynthetic gas exchange and regulate water loss from the plant. As such, stomatal size and density represent possible adaptations to conserve water. We hypothesized drought-tolerant ecotypes of big bluestem would have fewer or smaller stomates compared to more mesic ecotypes. Five ecotypes of big bluestem were planted in four common gardens from western Kansas to southern Illinois, USA to determine genetic and environmental influences on stomates. Leaves of all ecotypes of A. gerardii were largely hypostomatous and genetics was a greater influence than environment for stomatal size and density. The drought-tolerant Sand bluestem had larger stomates on abaxial surfaces of leaves, but a lower density compared to most other ecotypes. The most mesic Illinois ecotype and the Kaw cultivar had the greatest density of stomates on abaxial surfaces of leaves. Sand Bluestem had a greater density of stomates on adaxial surfaces of leaves compared to all other ecotypes. Gas exchange measures followed patterns of stomate distribution, where abaxial CO2 uptake rates were greater than adaxial CO2 uptake rates, although differences between leaf surfaces was more pronounced in stomatal density than in CO2 uptake. There were minor differences in size and density of stomates among sites that corresponded with precipitation, although these differences were minor, illustrating the genetic underpinnings of stomates in big bluestem. There is a genetic predisposition for drought-tolerant ecotypes to have fewer stomates, illustrating an evolutionary adaptation to drought tolerance in an important prairie species.

}, keywords = {LTER-KNZ}, doi = {10.1016/j.envexpbot.2018.07.018}, url = {https://linkinghub.elsevier.com/retrieve/pii/S0098847218300807}, author = {Varvel, Nick A. and Hilt, Christina J. and Johnson, Loretta C. and Galliart, Matthew and S.G. Baer and Maricle, Brian R.} } @article {KNZ001810, title = {Global synthesis of the temperature sensitivity of leaf litter breakdown in streams and rivers}, journal = {Global Change Biology}, volume = {23}, year = {2017}, pages = {3064-3075}, abstract = {

Streams and rivers are important conduits of terrestrially derived carbon (C) to atmospheric and marine reservoirs. Leaf litter breakdown rates are expected to increase as water temperatures rise in response to climate change. The magnitude of increase in breakdown rates is uncertain, given differences in litter quality and microbial and detritivore community responses to temperature, factors that can influence the apparent temperature sensitivity of breakdown and the relative proportion of C lost to the atmosphere vs. stored or transported downstream. Here, we synthesized 1025 records of litter breakdown in streams and rivers to quantify its temperature sensitivity, as measured by the activation energy (Ea, in eV). Temperature sensitivity of litter breakdown varied among twelve plant genera for which Ea could be calculated. Higher values of Ea were correlated with lower-quality litter, but these correlations were influenced by a single, N-fixing genus (Alnus). Ea values converged when genera were classified into three breakdown rate categories, potentially due to continual water availability in streams and rivers modulating the influence of leaf chemistry on breakdown. Across all data representing 85 plant genera, the Ea was 0.34 \± 0.04 eV, or approximately half the value (0.65 eV) predicted by metabolic theory. Our results indicate that average breakdown rates may increase by 5\–21\% with a 1\–4 \°C rise in water temperature, rather than a 10\–45\% increase expected, according to metabolic theory. Differential warming of tropical and temperate biomes could result in a similar proportional increase in breakdown rates, despite variation in Ea values for these regions (0.75 \± 0.13 eV and 0.27 \± 0.05 eV, respectively). The relative proportions of gaseous C loss and organic matter transport downstream should not change with rising temperature given that Ea values for breakdown mediated by microbes alone and microbes plus detritivores were similar at the global scale.

}, keywords = {LTER-KNZ}, doi = {10.1111/gcb.13609}, url = {https://onlinelibrary.wiley.com/doi/abs/10.1111/gcb.13609}, author = {Follstad-Shah, J.J. and Kominoski, John S. and Ard{\'o}n, Marcelo and W. K. Dodds and Gessner, Mark O. and Griffiths, Natalie A. and Hawkins, Charles P. and Johnson, Sherri L. and Lecerf, Antoine and LeRoy, Carri J. and Manning, David W. P. and Rosemond, Amy D. and Sinsabaugh, Robert L. and Swan, Christopher M. and Webster, Jackson R. and Lydia H. Zeglin} } @article {KNZ001845, title = {Grasshopper Sparrows Ecology}, journal = {Birding}, volume = {2}, year = {2017}, pages = {40-47}, keywords = {LTER-KNZ}, url = {http://publications.aba.org/}, author = {Kanning, Saraiya} } @mastersthesis {KNZ001832, title = {Grassland soil microbial responses to long-term management of N availability}, volume = {MS Thesis}, year = {2017}, school = {Kansas State University}, type = {M.S. Thesis}, address = {Manhattan, KS}, abstract = {

Anthropogenic actions have significantly increased biological nitrogen (N) availability on a global scale. In tallgrass prairies, this phenomenon is exacerbated by land management changes, such as fire suppression. Historically, tallgrass prairie fire removed N through volatilization, but fire suppression has contributed to increased soil N availability as well as woody encroachment. Because soil microbes respond to N availability and plant growth, these changes may alter microbial composition and important microbially-mediated functions. Grassland management affects the soil environment on multiple time scales including short (fertilization or fire event), seasonal (growing vs. non-growing season), and long-term (decadal plant turnover and nutrient accumulation), therefore my goal was to understand community variability at different time scales affecting the population and community dynamics of soil microbes. I predicted soil microbes would be sensitive to environmental changes at all time scales, seasonal variation would reflect increased plant rhizodeposit-supported populations during summer and decomposers during winter, and long-term fire suppression and chronic fertilization would drive soil microbial community turnover associated with accumulation of plant litter and N.

To address these predictions, soils were collected from the Belowground Plot Experiment (BGPE) at Konza Prairie Biological Station: a 30-y factorial field manipulation of N fertilization and burning. Surface soils (0-15 cm) were sampled monthly between Nov 2014 \– Dec 2015, including one week post-fire (April) and post-fertilization (June). Genomic DNA was extracted from each sample for qPCR and PCR for Illumina MiSeq library sequencing of the prokaryotic 16S rRNA gene and fungal ITS, to estimate population and community dynamics of soil microbes. Soil environmental characteristics and plant communities were measured in July 2015 to evaluate correlations between plant and microbial communities, and environmental variability.

Soil microbial responses to short-term fire/fertilization events were minimal, while microbial population sizes fluctuate seasonally and synchronously, and microbial community composition varied more with management history than at shorter time scales. Bacterial populations increased 10x during growing-season plant rhizodeposition, while fungal populations were less dynamic, but decreased in fall, possibly reflecting a shift to subsistence on soil organic matter. In contrast, microbial community composition was seasonally stable, but distinct between long-term management treatments, which may indicate accumulation of niche-defining plant or soil properties over decades. Prokaryotic communities responded to altered N availability via both fertilization and loss due to fire, with the highest abundance of \"copiotrophic\" (r-selected) taxa in unburned, fertilized soils. Fungal communities responded to N fertilization with higher abundance of arbuscular mycorrhizal fungi, pathogens, and saprotrophs, possibly due to changes in nutrient stoichiometry and litter availability in fertilized plots. However, fungal response to fire was largely independent of N availability, and plant community differences were correlated with fungal, but not bacterial, community composition, highlighting the likely nutritional codependence of fungi and plants, and fungal competitive advantages for plant litter substrates. The timing of changes in soil microbial communities is critical for plant nutrition and nutrient cycling in prairies, and this novel dataset on the temporal resolution of microbial responses to environmental variability contributes to the broader understanding of ecosystem responses to global change.

}, keywords = {LTER-KNZ, Communities, grassland, management, nitrogen, Soil microbes}, url = {http://krex.k-state.edu/dspace/handle/2097/36228}, author = {Carson, Christine} } @article {KNZ001758, title = {Grazing by bison is a stronger driver of plant ecohydrology in tallgrass prairie than fire history}, journal = {Plant and Soil}, volume = {411}, year = {2017}, pages = {423-436}, abstract = {

Background and Aims: Fire and grazing are important disturbances in grasslands, yet we know little about how they impact a variety of plant physiological processes such as plant ecohydrology. Here, we assessed the impact of fire history and grazing by Bison bison on the source of water uptake and niche overlap in common grassland species at the Konza Prairie Biological Station, a temperate mesic grassland located in northeastern Kansas, USA. Methods: We used the stable isotopic signature of soil and xylem water to evaluate water uptake in Andropogo n gerardii, Vernonia baldwinii, Amorpha canescens,and Rhus glabra within varying grazing (grazed, ungrazed), fire (0,1,2 or 3 years since last burn), topography (upland, lowland), and month (July, August) contrasts over 3 years (2013\–2015). Results: The presence of grazers, not fire history, altered water uptake patterns in these common grassland species. Particularly, grazing increased the proportion of shallow water utilized by A. gerardii and R. glabra, reducing niche overlap with other co-occurring species. However, these responses varied intra-annually and were often modulated by topography. Conclusions: These results suggest that grazing can alter aspects of grassland ecohydrology at small scales, which may extend to impact community and ecosystem processes at larger spatial scales.

}, keywords = {LTER-KNZ, fire, Herbivory, Mesic grassland, Niche overlap, Source water, Stable isotopes}, doi = {10.1007/s11104-016-3048-1}, url = {https://link.springer.com/article/10.1007\%2Fs11104-016-3048-1}, author = {O{\textquoteright}Keefe, K. and Jesse B. Nippert} } @article {KNZ001870, title = {Groundwater declines are linked to changes in Great Plains stream fish assemblages}, journal = {Proceedings of the National Academy of Sciences}, volume = {114}, year = {2017}, pages = {7373 - 7378}, abstract = {

Groundwater pumping for agriculture is a major driver causing declines of global freshwater ecosystems, yet the ecological consequences for stream fish assemblages are rarely quantified. We combined retrospective (1950\–2010) and prospective (2011\–2060) modeling approaches within a multiscale framework to predict change in Great Plains stream fish assemblages associated with groundwater pumping from the United States High Plains Aquifer. We modeled the relationship between the length of stream receiving water from the High Plains Aquifer and the occurrence of fishes characteristic of small and large streams in the western Great Plains at a regional scale and for six subwatersheds nested within the region. Water development at the regional scale was associated with construction of 154 barriers that fragment stream habitats, increased depth to groundwater and loss of 558 km of stream, and transformation of fish assemblage structure from dominance by large-stream to small-stream fishes. Scaling down to subwatersheds revealed consistent transformations in fish assemblage structure among western subwatersheds with increasing depths to groundwater. Although transformations occurred in the absence of barriers, barriers along mainstem rivers isolate depauperate western fish assemblages from relatively intact eastern fish assemblages. Projections to 2060 indicate loss of an additional 286 km of stream across the region, as well as continued replacement of large-stream fishes by small-stream fishes where groundwater pumping has increased depth to groundwater. Our work illustrates the shrinking of streams and homogenization of Great Plains stream fish assemblages related to groundwater pumping, and we predict similar transformations worldwide where local and regional aquifer depletions occur.

}, keywords = {LTER-KNZ}, doi = {10.1073/pnas.1618936114}, url = {https://www.pnas.org/content/114/28/7373}, author = {Perkin, Joshuah S. and K. B. Gido and Falke, Jeffrey A. and Fausch, Kurt D. and Crockett, Harry and Johnson, Eric R. and Sanderson, John} } @article {KNZ001869, title = {Gene expression patterns of two dominant tallgrass prairie species differ in response to warming and altered precipitation}, journal = {Scientific Reports}, volume = {6}, year = {2016}, pages = {25522}, abstract = {

To better understand the mechanisms underlying plant species responses to climate change, we compared transcriptional profiles of the co-dominant C4 grasses, Andropogon gerardii Vitman and Sorghastrum nutans (L.) Nash, in response to increased temperatures and more variable precipitation regimes in a long-term field experiment in native tallgrass prairie. We used microarray probing of a closely related model species (Zea mays) to assess correlations in leaf temperature (Tleaf) and leaf water potential (LWP) and abundance changes of ~10,000 transcripts in leaf tissue collected from individuals of both species. A greater number of transcripts were found to significantly change in abundance levels with Tleaf and LWP in S. nutans than in A. gerardii. S. nutans also was more responsive to short-term drought recovery than A. gerardii. Water flow regulating transcripts associated with stress avoidance (e.g., aquaporins), as well as those involved in the prevention and repair of damage (e.g., antioxidant enzymes, HSPs), were uniquely more abundant in response to increasing Tleaf in S. nutans. The differential transcriptomic responses of the co-dominant C4 grasses suggest that these species may cope with and respond to temperature and water stress at the molecular level in distinct ways, with implications for tallgrass prairie ecosystem function.

}, keywords = {LTER-KNZ}, doi = {10.1038/srep25522}, url = {https://www.nature.com/articles/srep25522}, author = {M.D. Smith and Hoffman, A.M. and M.L. Avolio} } @mastersthesis {KNZ001734, title = {Grasshopper sparrows on the move: patterns and causes of within-season breeding dispersal in a declining grassland songbird}, volume = {MS Thesis}, year = {2016}, school = {Kansas State University}, type = {M.S. Thesis}, address = {Manhattan, KS}, keywords = {LTER-KNZ}, url = {http://krex.k-state.edu/dspace/handle/2097/32705}, author = {Williams, E.J.} } @article {KNZ001689, title = {Global environmental change and the nature of aboveground net primary productivity responses: insights from long-term experiments}, journal = {Oecologia}, volume = {177}, year = {2015}, month = {Jan-04-2015}, pages = {935 - 947}, abstract = {

Many global change drivers chronically alter resource availability in terrestrial ecosystems. Such resource alterations are known to affect aboveground net primary production (ANPP) in the short term; however, it is unknown if patterns of response change through time. We examined the magnitude, direction, and pattern of ANPP responses to a wide range of global change drivers by compiling 73 datasets from long-term (\>5 years) experiments that varied by ecosystem type, length of manipulation, and the type of manipulation. Chronic resource alterations resulted in a significant change in ANPP irrespective of ecosystem type, the length of the experiment, and the resource manipulated. However, the pattern of ecosystem response over time varied with ecosystem type and manipulation length. Continuous directional responses were the most common pattern observed in herbaceous-dominated ecosystems. Continuous directional responses also were frequently observed in longer-term experiments (\>11 years) and were, in some cases, accompanied by large shifts in community composition. In contrast, stepped responses were common in forests and other ecosystems (salt marshes and dry valleys) and with nutrient manipulations. Our results suggest that the response of ANPP to chronic resource manipulations can be quite variable; however, responses persist once they occur, as few transient responses were observed. Shifts in plant community composition over time could be important determinants of patterns of terrestrial ecosystem sensitivity, but comparative, long-term studies are required to understand how and why ecosystems differ in their sensitivity to chronic resource alterations.

}, keywords = {LTER-KNZ, Aboveground productivity, Hierarchical response framework (HRF), Long-Term Ecological Research (LTER) Network, Nutrient addition, Precipitation manipulation}, issn = {0029-8549}, doi = {10.1007/s00442-015-3230-9}, url = {https://link.springer.com/article/10.1007\%2Fs00442-015-3230-9}, author = {M.D. Smith and Kimberly J. La Pierre and Scott. L. Collins and Alan K. Knapp and Gross, K.L. and Barrett, J.E. and Frey, S.D. and Gough, L. and Miller, R.J. and Morris, J.T. and Rustad, L.E. and Yarie, J.} } @article {KNZ001788, title = {Grassland productivity limited by multiple nutrients}, journal = {Nature Plants}, volume = {1}, year = {2015}, pages = {15080}, abstract = {

Terrestrial ecosystem productivity is widely accepted to be nutrient limited1. Although nitrogen (N) is deemed a key determinant of aboveground net primary production (ANPP)2,3, the prevalence of co-limitation by N and phosphorus (P) is increasingly recognized4,​5,​6,​7,​8. However, the extent to which terrestrial productivity is co-limited by nutrients other than N and P has remained unclear. Here, we report results from a standardized factorial nutrient addition experiment, in which we added N, P and potassium (K) combined with a selection of micronutrients (K+μ), alone or in concert, to 42 grassland sites spanning five continents, and monitored ANPP. Nutrient availability limited productivity at 31 of the 42 grassland sites. And pairwise combinations of N, P, and K+μ co-limited ANPP at 29 of the sites. Nitrogen limitation peaked in cool, high latitude sites. Our findings highlight the importance of less studied nutrients, such as K and micronutrients, for grassland productivity, and point to significant variations in the type and degree of nutrient limitation. We suggest that multiple-nutrient constraints must be considered when assessing the ecosystem-scale consequences of nutrient enrichment.

}, keywords = {LTER-KNZ}, doi = {10.1038/nplants.2015.80}, url = {https://www.nature.com/articles/nplants201580}, author = {Fay, P.A. and Prober, S.M. and Harpole, W.S. and Knops, J.M.H. and J.D. Bakker and E.T. Borer and Lind, E.M. and MacDougall, A.S. and Seabloom, E.W. and Wragg, P.D. and P. Adler and D.M. Blumenthal and Buckley, Y.M. and Chu, C. and Cleland, E.E. and Scott. L. Collins and Davies, K.F. and G. Du and Feng, X. and Firn, J. and Gruner, D.S. and Hagenah, N. and Hautier, Y. and Heckman, R.W. and Jin, V.L. and Kirkman, K.P. and Klein, J. and L. Ladwig and Li, Q. and McCulley, R.L. and Melbourne, B.A. and Mitchell, C.E. and Joslin L. Moore and J.W. Morgan and A. Risch and sch{\"u}tz, M. and Stevens, C.J. and Wedin, D.A. and Yang, L.H.} } @article {KNZ001553, title = {Geographic variation in growth and phenology of two dominant Central US grasses: Consequences for climate change}, journal = {Journal of Plant Ecology}, volume = {7}, year = {2014}, pages = {211 -221}, abstract = {

Aims The rate of climate change may exceed many plant species\’ migration rates, particularly for long-lived perennial species that dominate most ecosystems. If bioclimatic envelopes shift more rapidly than dominant species can migrate, individuals located peripheral to biomes or in adjacent biomes may become a significant source of traits for future dominant populations (DPs). Thus, traits of individuals from peripheral populations (PPs) may affect future ecosystem functioning more than those of today\’s DPs. Methods We assessed key traits of individuals collected from populations that currently dominate two central US grasslands, the shortgrass steppe (Bouteloua gracilis) and the tallgrass prairie (Andropogon gerardii). We compared these to individuals from PPs in a reciprocal-transplant common garden experiment with gardens at the Shortgrass Steppe Long Term Ecological Research site in Colorado and the Konza Prairie Biological Station Long Term Ecological Research site in Kansas. DPs and PPs were subjected to high and reduced water availability in common gardens located in each biome. Traits measured included the following: individual plant biomass, reproductive allocation, specific leaf area (SLA) and plant\–water relations. We focused on the climate-change relevant comparisons of traits from PPs versus DPs expressed under the climate of DPs. Important Findings PPs of B. gracilis differed from DPs primarily in phenological traits. Under a semiarid shortgrass steppe climate, PPs initiated flowering later in the season, produced fewer reproductive tillers and were more sensitive to water stress. Biomass differences between populations were minimal. For A. gerardii, biomass in PPs was 50\% lower than in DPs under the mesic tallgrass prairie climate and reproductive tillers were considerably smaller, despite higher SLA in PPs. Biomass of PPs was less sensitive to water stress, however. From these results, we conclude that key traits of PPs differed from DPs in both grassland types, but potential effects on reproductive phenology were greater for the bioclimatic shift in which a mesic biome becomes arid, whereas aboveground productivity may be affected more when a semiarid biome becomes more mesic.

}, keywords = {LTER-KNZ, grassland, phenology, productivity, traits, water stress}, doi = {10.1093/jpe/rtt036}, url = {https://academic.oup.com/jpe/article/7/3/211/905746}, author = {Giuliani, A.L. and Kelly, E.F. and Alan K. Knapp} } @inbook {KNZ001656, title = {Grassland Ecology}, booktitle = {Plant Sciences - Ecology and the Environment}, volume = {8}, number = {Springer Reference Series}, year = {2014}, pages = {389-423}, publisher = {Springer-Verlag Berlin Heidelberg}, organization = {Springer-Verlag Berlin Heidelberg}, keywords = {LTER-KNZ}, author = {John M. Blair and Jesse B. Nippert and J. M. Briggs}, editor = {Monson, R} } @article {KNZ001505, title = {Genetic diversity of a dominant C4 grass is altered with increased precipitation variability}, journal = {Oecologia}, volume = {171}, year = {2013}, pages = {571 -581}, abstract = {

Climate change has the potential to alter the genetic diversity of plant populations with consequences for community dynamics and ecosystem processes. Recent research focused on changes in climatic means has found evidence of decreased precipitation amounts reducing genetic diversity. However, increased variability in climatic regimes is also predicted with climate change, but the effects of this aspect of climate change on genetic diversity have yet to be investigated. After 10 years of experimentally increased intra-annual variability in growing season precipitation regimes, we report that the number of genotypes of the dominant C4 grass, Andropogon gerardii Vitman, has been significantly reduced in native tallgrass prairie compared with unmanipulated prairie. However, individuals showed a different pattern of genomic similarity with increased precipitation variability resulting in greater genome dissimilarity among individuals when compared to unmanipulated prairie. Further, we found that genomic dissimilarity was positively correlated with aboveground productivity in this system. The increased genomic dissimilarity among individuals in the altered treatment alongside evidence for a positive correlation of genomic dissimilarity with phenotypic variation suggests ecological sorting of genotypes may be occurring via niche differentiation. Overall, we found effects of more variable precipitation regimes on population-level genetic diversity were complex, emphasizing the need to look beyond genotype numbers for understanding the impacts of climate change on genetic diversity. Recognition that future climate change may alter aspects of genetic diversity in different ways suggests possible mechanisms by which plant populations may be able to retain a diversity of traits in the face of declining biodiversity.

}, keywords = {LTER-KNZ, AFLP, Andropogon gerardii, Dice dissimilarity, dominant species, Genotypic structure}, doi = {10.1007/s00442-012-2427-4}, url = {https://link.springer.com/article/10.1007\%2Fs00442-012-2427-4}, author = {M.L. Avolio and Beaulieu, J. and M.D. Smith} } @article {KNZ001528, title = {Genetic variation and mating success in managed American plains bison}, journal = {Journal of Heredity}, volume = {104}, year = {2013}, pages = {182 -191}, abstract = {

The American plains bison (Bison bison) was pushed to the brink of extinction in the late 1800s but has since rebounded. Less than 5\% of animals currently exist in conservation herds that are critical for maintaining genetic variability. Here, we use 25 microsatellite loci to assess genetic diversity and patterns of mating success over a 3-year period in a managed conservation herd at Konza Prairie Biological Station, Kansas (total number of individuals genotyped = 587). Heterozygosity was comparable to and allelic diversity higher than that in 11 other wild and managed herds for which similar estimates are available. Parentage analyses revealed that males within the oldest age classes (5\–7 years) sired \>90\% of calves over the study period, consistent with a polygynous breeding system. Asymmetries in siring success also were observed within age classes, with the same males enjoying high siring success over multiple seasons. Empirical results of paternity will facilitate future modeling and empirical efforts to determine how demographic factors, population size, and variation in siring success interact to determine the retention (or loss) of genetic diversity in natural and managed herds, thus allowing informed recommendations for management practices and conservation efforts of this symbolic North American species.

}, keywords = {LTER-KNZ}, doi = {10.1093/jhered/ess095}, url = {https://academic.oup.com/jhered/article/104/2/182/802105}, author = {Ungerer, M.C. and Weitekamp, C.A. and Anthony Joern and Towne, G. and J. M. Briggs} } @article {KNZ001658, title = {Genotypic diversity of a dominant C4 grass across a long-term fire frequency gradient}, journal = {Journal of Plant Ecology}, volume = {6}, year = {2013}, pages = {448 -458}, abstract = {

Aims and Methods Diversity-disturbance research has focused on community diversity, but disturbance frequency could impact diversity within species as well, with important consequences for community diversity and ecosystem function. We examined patterns of genetic diversity of a dominant grass species, Andropogon gerardii, in native North American tallgrass prairie sites located in eastern Kansas that have been subjected to a gradient of fire frequency treatments (burned every 1, 2, 4 or 20 years) since the 1970s. In addition, we were able to assess the relationships between genetic diversity of A. gerardii, species diversity and productivity across this range of fire frequencies. Important Findings We found no significant relationships between genetic diversity of A. gerardii at the local scale (1 m2 plot level) and disturbance frequency (burned 2 to 32 times over a 38-year period). However, at the site level (i.e. across all plots sampled within a site, ~100 m2) there were differences in genotype richness and composition, as well as genomic dissimilarity among individuals of A. gerardii. Genotype richness was greatest for the site burned at an intermediate (4-year) frequency and lowest for the infrequently (20-year) burned site. In addition, genotypes found in the frequently burned sites were more similar from each other than expected by random chance than those found in the infrequently burned sites. Genotype composition of A. gerardii was not significantly different between the frequently burned sites (annual vs. 2 year) but did differ between frequently burned and infrequently burned sites (1 and 2 year vs. 4 and 20 year, etc.). Together, these results suggest site-level ecological sorting of genotypes in intact prairie across a broad gradient of disturbance frequencies, likely driven by alterations in environmental conditions. Frequent fire promotes the abundance of dominant grass species, reduces plant community diversity and impacts ecosystem processes such as productivity. Our study suggests that genetic diversity within dominant grass species also may be affected by disturbance frequency, which could have important implications for how species are able to respond to disturbance.

}, keywords = {LTER-KNZ, Andropogon gerardii, disturbance frequency, genetic relatedness, genetic-species diversity relationship, genotype richness, intermediate disturbance hypothesis, productivity, tallgrass prairie}, doi = {10.1093/jpe/rtt006}, url = {https://academic.oup.com/jpe/article/6/6/448/980977}, author = {Chang, C.C. and M.D. Smith} } @article {KNZ001488, title = {Global diversity of drought tolerance and grassland climate-change resilience}, journal = {Nature Climate Change}, volume = {3}, year = {2013}, pages = {63 -67}, abstract = {

Drought reduces plant productivity, induces widespread plant mortality and limits the geographic distribution of plant species1, 2, 3, 4, 5, 6, 7. As climates warm and precipitation patterns shift in the future8, 9, understanding the distribution of the diversity of plant drought tolerance is central to predicting future ecosystem function and resilience to climate change10, 11, 12. These questions are especially pressing for the world\’s 11,000 grass species13, which dominate a large fraction of the terrestrial biosphere14, yet are poorly characterized with respect to responses to drought. Here, we show that physiological drought tolerance, which varied tenfold among 426 grass species, is well distributed both climatically and phylogenetically, suggesting most native grasslands are likely to contain a high diversity of drought tolerance. Consequently, local species may help maintain ecosystem functioning in response to changing drought regimes without requiring long-distance migrations of grass species. Furthermore, physiologically drought-tolerant species had higher rates of water and carbon dioxide exchange than intolerant species, indicating that severe droughts may generate legacies for ecosystem functioning. In all, our findings suggest that diverse grasslands throughout the globe have the potential to be resilient to drought in the face of climate change through the local expansion of drought-tolerant species.

}, keywords = {LTER-KNZ, Climate-change ecology, Drought, Grassland ecology}, doi = {10.1038/nclimate1634}, url = {https://www.nature.com/articles/nclimate1634}, author = {Craine, J.M. and Ocheltree, T.W. and Jesse B. Nippert and Towne, E.G. and Skibbe, A.M. and Kembel, S.W. and Fargione, J.E.} } @article {KNZ001572, title = {Grass fires - an unlikely process to explain the magnetic properties of prairie soils}, journal = {Geophysical Journal International}, volume = {195}, year = {2013}, pages = {1566 -1575}, abstract = {

It has been proposed that grass fires affect the magnetic properties of soils by combining generally reducing soil conditions with elevated temperatures. To explore this supposition, we analysed surface and subsurface samples from loessic soils and compared their differences in magnetic properties as a function of fire intensity. Fire intensity was established based on types of burnt vegetation, which ranged from low-intensity fires in short-grass areas to high-intensity fires in tall-grass and forested areas. We measured low-field magnetic susceptibility (χ), a common proxy for the abundance of magnetic minerals, frequency-dependent susceptibility (χFD), a proxy for the presence of ultrafine-grained superparamagnetic minerals, and susceptibility of anhysteretic remanent magnetization (χARM), a magnetic parameter highly dependent on the presence of fine, single-domain magnetic particles. Although intense fires led to an increase in frequency-dependent susceptibility and low-field magnetic susceptibility, moderately intense fires did not produce significant changes in magnetic properties. Observed magnetic changes are limited to sites that were very heavily burnt in forest areas. Grass fires are therefore an unlikely mechanism to explain a measurable component of the magnetic enhancement in prairie soils.

}, keywords = {LTER-KNZ, Environmental magnetism, North America, Rock and mineral magnetism}, doi = {10.1093/gji/ggt349}, url = {https://academic.oup.com/gji/article/195/3/1566/625447}, author = {Roman, S.A. and Johnson, W.C. and Geiss, C.E.} } @phdthesis {KNZ001669, title = {Grassland invasion by non-native grass species: ecological issues of multiple species at multiple trophic levels}, volume = {PhD. Dissertation}, year = {2013}, school = {Oklahoma State University}, type = {Ph.D. Thesis}, address = {Stillwater, OK}, abstract = {

Invasion of native grasslands by non-native grasses is of great economic and ecologic concern. Non-native grasses have potential to alter ecosystem functions, habitat quality, disturbance regimes, and feedback loops. These alterations can have bottom-up or top-down effects that may negatively influence grasslands at multiple trophic levels. I conducted three integrated studies to assess non-native grass invasion: 1) on the competitive interactions between native vs. non-native grass species with community-level implications; 2) possible utilization of allelopathic biochemicals as an invasion mechanism; and 3) possible alterations in the small mammal communities with implications for ecosystem-level function. My first study indicated that both invasive and native species varied in mycorrhizal dependency along a continuum from obligately to facultatively dependent. Native species biomass production was consistently reduced when planted into \&$\#$39;away\&$\#$39; soil, as compared to \&$\#$39;home\&$\#$39; soil. Increased biomass production of native grasses was consistently observed following additions of native prairie soil to steam-pasteurized soil from the invaded sites, indicating invasive feedbacks may occur through alterations in biotic communities. My second study indicated that Bothriochloa spp. may gain a competitive advantage through the use of allelopathic biochemicals. However, it is unclear if these allelopathic effects directly hinder competitors, or indirectly hinder competitors through alterations of soil microbial communities. Determination of allelopathic biochemicals was not definitive. Data from my third study indicate that invasion of B. ischaemum into the native grasslands lowered all abundance metrics for deer mice (Peromyscus maniculatus), while increasing all abundance metrics for hispid cotton rats (Sigmodon hispidus), as compared to native grassland controls. Species-specific models show cotton rats select vegetation that supplies aerial predator avoidance and deer mice select habitat that increases foraging efficency. Alterations in these small mammal communities may have profound effects on ecosystem functioning. Our research indicates non-native grass invasion alters native communities on multiple trophic levels. I propose management practices for restoration may be most successful if determined on a species-specific and site-specific basis, as different species appear to use different mechanisms for successful invasion into native prairies.

}, keywords = {LTER-KNZ}, url = {https://shareok.org/handle/11244/14859}, author = {Greer, M.J.} } @phdthesis {KNZ001570, title = {Grassland restoration in a changing world: consequences of practices and variable environments}, volume = {PhD. Dissertation}, year = {2013}, school = {Kansas State University}, type = {Ph.D. Thesis}, address = {Manhattan, KS}, abstract = {

The feasibility of restoration, which traditionally targets historical conditions, is questionable in the context of global change. To address this, my dissertation investigated (Chapter 2) the patterns of restoration establishment along a chronosequence of restored prairies with respect to nearby remnant prairies, (Chapters 3-4) responses of plant communities in restorations initiated using different methods (levels of species richness and sowing density) to drought, which is projected to increase in frequency, and (Chapters 5-6) the effects of propagule source and variation (mixing among sources) on restoration establishment and the generality of restoration outcomes across variable environments using reciprocal common gardens of multi-species restoration seedings. Chapter 2, published in Restoration Ecology, showed that restoration led to the recovery of desirable characteristics within several years, but restorations utilizing primarily fall-collected seeds likely diminished the representation of early phenology species, so biodiversity may be further enhanced by including early phenology species in seeding mixes. Chapters 3 and 4, published respectively in Ecological Applications and Applied Vegetation Science, examined the establishment of native plant communities after seeding and their responses to experimentally imposed drought. Both high seed mixture richness and high density seeding resulted in greater establishment of native, seeded species compared to low richness and low density treatments, and exotic species were less prevalent in high richness and high density treatments. However, we found little evidence of differential drought resistance, recovery, and resilience among treatments. This result coupled with increases in exotic species following drought suggest that other forms of active management may be needed to produce restored plant communities that are robust to climate change. Chapter 5 (published in Ecosphere) and Chapter 6 found that seed source affects individual species establishment, community structure, and productivity. However, there was no consistent advantage for any source, including local sources, across sites or species. This suggests that source effects on single species or effects observed at single locations should not be broadly generalized. Together, this dissertation shows that restoration can recover many characteristics of native prairies and that manipulation of seeding practices (seed mixture richness, seeding density, seed source) influence grassland establishment in terms of productivity, community structure, invasion, and the abundance and survival of individual species.

}, keywords = {LTER-KNZ, chronosequence, Climate change, common garden, local adaptation, tallgrass}, url = {http://hdl.handle.net/2097/15357}, author = {Carter, D.L.} } @phdthesis {KNZ001571, title = {Grazing and drought in tallgrass prairie: the role of belowground bud banks in vegetation dynamics}, volume = {PhD. Dissertation}, year = {2013}, school = {Kansas State University}, type = {Ph.D. Thesis}, address = {Manhattan, KS}, abstract = {

Grazing and drought are instrumental in the development and maintenance of perennial grasslands. In this research I tested the belowground bud bank contribution to tallgrass prairie resistance and resilience when perturbed by grazing and drought. First, I tested the bud bank role in vegetation response to and recovery from severe drought (Chapter 2). I compared above- and belowground responses of experimentally droughted plots to ambient controls and irrigated plots during two years of severe drought and two years of recovery. I found that although aboveground net primary productivity declined 30-60\% during drought, bud bank density and demography were insensitive to drought. These results suggest that grassland resistance and resilience when perturbed by drought may be mediated by stability of belowground bud banks. Second, I investigated vegetation and soil nutrient legacies following release from long-term grazing (Chapter 3). I documented a relatively rapid shift in aboveground vegetation within four years of grazer exclusion, with productivity, stem density, and diversity becoming relatively more similar to ungrazed than grazed prairie. The density and composition of the belowground bud bank and soil seed bank shifted more slowly, remaining more similar to grazed than ungrazed prairie. Responses of soil nutrients to removal of grazers varied, and in some cases was affected by recent fire history. These results demonstrate the contribution of belowground propagules to the maintenance of a diverse plant community both during grazing and after grazers are removed. Finally, I examined short-term vegetation responses to both drought and grazing (Chapter 4). Despite extreme drought and simulated grazing that reduced productivity and increased mortality of individual stems, the dominant C4 grasses maintained a stable bud bank. Aboveground net primary productivity and bud bank density of sedges and forbs, however, were reduced by both drought and grazing. This differential response of species to extreme drought and grazing led to shifts in community composition and species diversity over one growing season. Across drought and grazing treatments, live rhizome biomass was highly correlated with bud bank density and may be a useful, more easily measured index of bud bank density.

}, keywords = {LTER-KNZ, Bud bank, Grazing; Drought, Resistance and resilience, Seed bank, tallgrass prairie}, url = {http://hdl.handle.net/2097/16622}, author = {VanderWeide, B.L.} } @phdthesis {KNZ001480, title = {Genetic diversity of Andropogon gerardii: Impacts of altered precipitation patterns on a dominant species}, volume = {PhD Dissertation}, year = {2012}, pages = {1 -258}, school = {Yale University}, type = {Ph.D. Thesis}, address = {New Haven, CT}, abstract = {

Global change is expected to shift climatic regimes and cause whole communities of organisms to experience novel environments. Key aspects of forecast climate change are alterations in both the amount of precipitation and the variability of precipitation regimes. The ability of a population to adapt will depend on the genetic diversity of the population, and the traits of the genotypes present in the population. Here, I assess the response a dominant C4 tallgrass population to novel environmental conditions resulting from forecast climate change by studying whether more variable precipitation patterns affect the genetic diversity of Andropogon gerardii. I then investigate the potential mechanisms driving the observed response. Ultimately, the way in which population genetic diversity is affected by more variable precipitation patterns will shed insight into how this important species will adapt to future climate change. First, I developed the tools to study the genetic diversity of A. gerardii at the plant neighborhood scale, the scale at which individuals compete for resources. I designed amplified fragment length polymorphism primers for A. gerardii and determined the appropriate scale at which to sample individuals to accurately capture genetic diversity. I also examined how genetic diversity is measured in ecological studies by comparing genotype-based measures and genome-based measures of diversity. Ultimately, I argue that genome-based measures should be included in future studies alongside genotypic-based measures because they capture a greater spectrum of genetic differences among individuals. Next, using what I established for studying genetic diversity, I examined how a decade of altered precipitation patterns affected the genetic diversity of A. gerardii. To do this I worked within the Rainfall Manipulation Plots (RaMPs) experiment at Konza Prairie Biological Station in Kansas, which experimentally imposes ambient and more variable precipitation patterns. After ten years of experimentally increased intra-annual variability in growing season precipitation regimes, I report that the number of genotypes of the dominant C4 grass, Andropogon gerardii Vitman, has been significantly reduced in native tallgrass prairie compared with unmanipulated prairie. However, individuals showed a different pattern of genomic similarity with increased precipitation variability \– there was greater genome dissimilarity among individuals when compared to unmanipulated prairie. In my next two chapters, I aim to understand the mechanism that drove the observed shift in genetic diversity. First, I studied phenotypic differences among six common genotypes of Andropogon gerardii across three different environmental conditions to study genotype \× environmental interactions. I consistently detected differences among the focal genotypes for all traits measured across environmental treatments, however, I observed no genotype \× year interactions, and phenotypic differences among genotypes were diminished within environmental conditions. To assess potential mechanisms underlying the changes observed in population structure of this species, I continued to study five of the same genotypes, three of which had greater abundances or were only present in plots receiving more variable rainfall patterns. In a greenhouse study, I investigated how both changes in the size and variability of watering events affected ecophysiological, growth, biomass allocation and fitness traits. I found genotype \× water amount interactions for traits related to leaf level physiology and biomass allocation; genotypes that performed better under low soil moisture conditions were outperformed by other genotypes under high soil moisture conditions. For the three genotypes that had greater abundance in plots that received a decade of altered rainfall regimes, I found evidence of phenotypic trait divergence as well as greater plasticity for ecophysiological traits. Lastly, I investigated correlations between species and genetic diversity in tallgrass prairie across an experimental manipulation of soil moisture. I found species and genetic diversity were not correlated, and that genotypic richness was negatively related to soil moisture variability, but measures of species diversity were not related to soil moisture. My results suggest that a lack relationship between species and genetic diversity at the populations scale could be because species and genetic diversity are responding differently to environmental resources. Ultimately, my dissertation is an in-depth examination of how environmental conditions affect the genetic diversity of a dominant species. I found that for genetically diverse species, such as dominant species, microevolution might be an important aspect of adaptation to novel environmental conditions experienced with climate change.

}, keywords = {LTER-KNZ}, url = {http://search.proquest.com/docview/1272028956}, author = {M.L. Avolio} } @phdthesis {KNZ001477, title = {Growth and survival during drought: The link between hydraulic architecture and drought tolerance in grasses}, volume = {PhD Dissertation}, year = {2012}, pages = {1 -1117}, school = {Kansas State University}, type = {Ph.D. Thesis}, address = {Manhattan, KS}, abstract = {

The pathway for the movement of water through plants, from the soil matrix to the atmosphere, constitutes the hydraulic architecture of a plant. The linkage between the hydraulic architecture of woody plants and drought tolerance has received considerable attention, but much less work has been done on grasses. I investigated the linkage between the hydraulic architecture of grasses to physiological patterns of water use across a range of species and conditions. The rate of stomatal conductance (g[subscript]s) and photosynthesis (A) increased acropetally along the leaves of 5 grass species, which is a unique feature of this growth form. The internal structure of leaves also changed acropetally in order to minimize the pressure gradient across the mesophyll that would otherwise occur as a result of increasing g[subscript]s. The resistance to water movement through the mesophyll represented 80-90\% of leaf resistance in six genotypes of Sorghum bicolor L. (Moench). This resistance was most important in controlling g[subscript]s and A when water was readily available, but as soil-moisture decreased it was the efficient transport of water through the xylem that was most important in maintaining plant function. I also investigated the relationship between hydraulic architecture and stomatal responses of grasses to increasing Vapor Pressure Deficit (D). Grasses with a larger proportion of their hydraulic resistance within the xylem were less sensitive to increasing D and plants with high root conductance maintained higher rates of gas exchange D increased. Finally, I investigated the tolerance of grasses to extreme drought events to test if there was a trade-off between drought tolerance and growth in grasses. Plants with drought tolerant leaf traits typically sacrificed the ability to move water efficiently through their leaves. Having drought tolerant leaves did not limit the plants ability to have high rates of gas exchange, and, in fact, the most drought tolerant plants had the high rates of g[subscript]s when expressed on a mass basis. Leaf-level drought tolerance did contribute to species\’ occurrence, as the drought intolerant species I studied are not commonly found in low precipitation systems. The results presented here highlight the importance of studying the hydraulic architecture of plants to provide a better understanding of what controls plant function across a range of environmental conditions.

}, keywords = {LTER-KNZ, Drought Tolerance, Grass Anatomy, Grass Physiology, Plant Hydraulic Architecture, Stomatal Conductance}, url = {http://hdl.handle.net/2097/13803}, author = {Ocheltree, T.W.} } @mastersthesis {KNZ001470, title = {A generalist grasshopper species (Melanoplus femurrubrum) is adapted to variable environments along a latitudinal gradient}, volume = {MS Thesis}, year = {2011}, school = {Kansas State University}, type = {M.S. Thesis}, address = {Manhattan, KS}, abstract = {

Temperature and food quality vary across broad latitudinal gradients, greatly affecting performance by insect herbivores. The contribution of each varies latitudinally so that geographically distinct populations are challenged by differences in nutritional needs and energetic demands. While there has been extensive work studying diet selectivity and nutritional ecology of insect herbivores, few studies have focused on how insect herbivores adapt across such vast environmental gradients. The generalist-feeding grasshopper, Melanoplus femurrubrum (DeGreer), has a broad geographic range that extends across much of North America, making this species ideal for comparative investigations of intrinsic performance responses to extensive but predictable patterns of environmental variation. I compared responses by six populations collected from populations located from Texas to North Dakota (USA) using a common garden experimental design to investigate clinal responses in grasshopper performance. I examined responses in: (1) body size, (2) thermoregulation and adaptive coloration, (3) developmental and growth rates, (4) metabolic rates, (5) total consumption and rates, (6) diet ratio selection, and (7) digestive processing efficiencies across the latitudinal gradient. Grasshopper body size followed the Converse Bergmann\’s Rule with decreasing body size as latitude increased. Temperature influenced all other responses, but responses to diet were not always significant or directional. Latitudinal trends for development and growth rates were observed but mass-specific metabolic rates were similar for all populations. Total consumption was body size dependent but independent of diet type. Mass-specific consumption varied but no single directional trend was detected. There was a shift in carbohydrate-biased diet preference at low latitude toward protein-biased diet ratios at higher latitudes, suggesting adaptations to different energetic demands by these populations. However, post-ingestive (digestive) efficiencies demonstrated variable responses with northern populations observing highest efficiencies for some indices but not all. Overall, this research documents phenotypic plasticity to environmental variability to some degree for digestive efficiencies, but ecotypic responses in body size and diet preference among M. femurrubrum populations were observed.

}, keywords = {LTER-KNZ, body size, latitudinal gradient, Melanoplus femurrubrum, nutritional ecology, Performance, Temperature}, url = {http://hdl.handle.net/2097/13093}, author = {Parsons, S.} } @article {KNZ001337, title = {Genetic parentage and local population structure in the socially monogamous Upland Sandpiper}, journal = {Condor}, volume = {113}, year = {2011}, pages = {119 -128}, abstract = {

For a single lineage of birds, the diversity of mating systems and parental care among shorebirds (Charadrii) is high, which has made them an important group for investigations of the evolution of social mating systems. From 2003 to 2007, we studied a population of the Upland Sandpiper (Bartramia longicauda) at Konza Prairie Biological Station in northeastern Kansas. Our objectives were to determine the genetic mating system of this socially monogamous shorebird and to determine whether spatial patterns of philopatry and nest placement might affect opportunities for extra-pair mating. We used six microsatellite markers to estimate rates of extra-pair paternity in 58 family groups (107 parents, 184 offspring). We found that 30\% of broods contained extra-pair offspring, representing 15\% of chicks, the highest rate of extra-pair paternity ever reported in a socially monogamous shorebird. High rates of extra-pair paternity were not due to the degree of relatedness between partners in mated pairs, and they did not result in greater diversity among broods with extra-pair young. We used a spatial genetic-autocorrelation analysis and found evidence for relatedness among females nesting \<1 km apart. The Upland Sandpiper might have a high rate of extra-pair paternity because related females nest synchronously and in close proximity, but the probability of extra-pair young was not related to nest density or distance to nearest nest. Female-biased natal philopatry is unusual among birds but is consistent with the mate-defense mating system of the Upland Sandpiper.

}, keywords = {LTER-KNZ, Bartramia longicauda, dispersal, Extra-pair paternity, genetic structure, mating systems, natal philopatry, shorebirds, Upland Sandpiper}, doi = {10.1525/cond.2011.100100}, url = {https://doi.org/10.1525/cond.2011.100100}, author = {Casey, A.E. and Sandercock, B.K. and Wisely, S.M.} } @article {KNZ001395, title = {Genomic and resistance gene homolog diversity of the dominant tallgrass prairie species across the U.S. Great Plains precipitation gradient}, journal = {PLoS ONE}, volume = {6:e17641}, year = {2011}, abstract = {

Background Environmental variables such as moisture availability are often important in determining species prevalence and intraspecific diversity. The population genetic structure of dominant plant species in response to a cline of these variables has rarely been addressed. We evaluated the spatial genetic structure and diversity of Andropogon gerardii populations across the U.S. Great Plains precipitation gradient, ranging from approximately 48 cm/year to 105 cm/year. Methodology/Principal Findings Genomic diversity was evaluated with AFLP markers and diversity of a disease resistance gene homolog was evaluated by PCR-amplification and digestion with restriction enzymes. We determined the degree of spatial genetic structure using Mantel tests. Genomic and resistance gene homolog diversity were evaluated across prairies using Shannon\&$\#$39;s index and by averaging haplotype dissimilarity. Trends in diversity across prairies were determined using linear regression of diversity on average precipitation for each prairie. We identified significant spatial genetic structure, with genomic similarity decreasing as a function of distance between samples. However, our data indicated that genome-wide diversity did not vary consistently across the precipitation gradient. In contrast, we found that disease resistance gene homolog diversity was positively correlated with precipitation. Significance Prairie remnants differ in the genetic resources they maintain. Selection and evolution in this disease resistance homolog is environmentally dependent. Overall, we found that, though this environmental gradient may not predict genomic diversity, individual traits such as disease resistance genes may vary significantly.

}, keywords = {LTER-KNZ, Amplified fragment length polymorphism, Cloning, Hexaploidy, Maize, Plant genomics, Plant pathology, Ploidy, Population genetics}, doi = {10.1371/journal.pone.0017641}, url = {https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0017641}, author = {Rouse, M.N. and Saleh, A.A. and Seck, A. and Keeler, K.H. and Travers, S.E. and Hulbert, S.H. and Garrett, K.A.} } @article {KNZ001359, title = {Grasshopper fecundity responses to grazing and fire in a tallgrass prairie}, journal = {Environmental Entomology}, volume = {40}, year = {2011}, pages = {979 -988}, abstract = {

Grasshopper abundance and diversity vary with management practices such as fire and grazing. Understanding how grasshopper life history traits such as fecundity respond to management practices is key to predicting grasshopper population dynamics in heterogeneous environments. Landscape-level experimental fire and bison grazing treatments at the Konza Prairie Biological Station (Manhattan, KS) provide an opportunity to examine how management affects grasshopper fecundity. Here we report on grasshopper fecundity for nine common species at Konza Prairie. From 2007 to 2009, adult female grasshoppers were collected every 3 wk from eight watersheds that varied in fire and grazing treatments. Fecundity was measured by examining female reproductive tracts, which contain a record of past and current reproductive activity. Body size was a poor predictor of fecundity for all species. Despite large differences in vegetation structure and composition with management regime (grazing and fire interval), we observed little effect of management on grasshopper fecundity. Habitat characteristics (grasshopper density, vegetation biomass, and vegetation quality; measured in 2008 and 2009) were better predictors of past fecundity than current fecundity, with species-specific responses. Fecundity increased throughout the summer, indicating that grasshoppers were able to acquire sufficient nutritional resources for egg production in the early fall when vegetation quality is generally low. Because fecundity did not vary across management treatments, population stage structure may be more important for determining population level reproduction than management regime at Konza Prairie.

}, keywords = {LTER-KNZ, Konza Prairie Biological Station, life-history, management, Orthoptera, reproduction}, doi = {10.1603/EN10146}, url = {https://academic.oup.com/ee/article-abstract/40/5/979/412531?redirectedFrom=fulltext}, author = {Laws, A. and Anthony Joern} } @article {KNZ001336, title = {Grasshoppers (Orthoptera: Acrididae) select vegetation patches in local-scale responses to foliar nitrogen but not phosphorus in native grassland}, journal = {Insect Science}, volume = {18}, year = {2010}, pages = {533 -540}, abstract = {

Key elements such as nitrogen (N) and phosphorus (P) are often limiting relative to the nutritional needs of herbivores that feed on them. While N often limits insect herbivores in natural terrestrial ecosystems, the effect of P is poorly studied in the field, even though compelling hypotheses from the ecological stoichiometry literature predict its importance. We evaluated small-scale spatial distributions of, and herbivory by, grasshoppers among neighboring plots that vary in foliar-N and -P in tallgrass prairie. Grasshopper densities were 67\% greater in N-fertilized plots but detected no effect to grasshopper densities from P-fertilizer. Leaf damage to the dominant grass Andropogon gerardii was 32\% greater in N-fertilized plots, but no response to foliar-P was detected. Herbivore damage to a common forb, goldenrod (Solidago missouriensis), was not strongly linked by fertilizer treatments, although there was increased leaf damage in N-fertilizer treatments when no P was applied (a significant N \× P interaction). Under field conditions at local scales, we conclude that spatially heterogeneous distributions of grasshoppers are primarily affected by foliar-N in host plants with little evidence that P-levels contribute to the spatial patterns.

}, keywords = {LTER-KNZ, Andropogon gerardii, ecological stoichiometry, insect herbivory, Konza Prairie, N-P fertilization experiment, Solidago missouriensis}, doi = {10.1111/j.1744-7917.2010.01376.x}, url = {https://onlinelibrary.wiley.com/doi/abs/10.1111/j.1744-7917.2010.01376.x}, author = {Loaiza, V. and Jonas, J.L. and Anthony Joern} } @book {KNZ001233, title = {Grasses and Grassland Ecology}, year = {2009}, pages = {320 -}, publisher = {Oxford University Press}, organization = {Oxford University Press}, address = {Oxford, UK}, keywords = {LTER-KNZ}, author = {D.J. Gibson} } @proceedings {KNZ001267, title = {Groundwater CO2: Is it responding to atmospheric CO2?}, volume = {II}, year = {2009}, pages = {995 -998}, keywords = {LTER-KNZ}, author = {G. L. Macpherson} } @article {KNZ001229, title = {Geographic patterns of song similarity in the Dickcissel (Spiza americana)}, journal = {Auk}, volume = {125}, year = {2008}, pages = {953 -964}, abstract = {

Song sharing among neighboring males is a well-known, frequent outcome of song learning in oscine passerines and some other groups, but only limited investigations of the spatial scale of this phenomenon have been pursued. On the basis of recordings of 1,043 individuals, we investigated song sharing in Dickcissels (Spiza americana) at local and regional scales at sites from northern Kansas to northern Oklahoma. Classification of song elements revealed decreasing song similarity with increasing distances between individual birds at small to intermediate scales, to ~10 km. At the largest spatial scales (10\–300 km between sites), there was very little similarity among sites and no obvious tendency for a decrease in similarity with increasing distances among our 30 sites. At our intensively sampled site, analyses of quantitative measurements showed that, at least for our most widely shared song element, frequency and duration were more similar in closer birds. Thus, distance between birds influences both quantitative and qualitative song similarity in Dickcissels. Variability existed among sites in the shape of the song-sharing decay curve, which indicates that other factors besides distance also govern song-sharing patterns. We found high repeatability of individual songs for both second-year (SY) and after-second-year (ASY) males throughout the season, and high conformity to the local song neighborhood in both SY and ASY males from their first recording soon after arrival in May. Returning ASY males sang the same song they had produced the previous breeding season.

}, keywords = {LTER-KNZ, culture, dialect, Dickcissel, Passeriformes, song sharing, spatial scale, Spiza americana}, doi = {10.1525/auk.2008.07164}, url = {https://academic.oup.com/auk/article/125/4/953/5148170}, author = {Schook, D.M. and Collins, M.D. and Jensen, W.E. and Williams, P.J. and Bader, N.E. and Parker, T.H.} } @article {KNZ001140, title = {Grassland establishment under varying resource availability: A test of positive and negative feedback}, journal = {Ecology}, volume = {89}, year = {2008}, pages = {1859 -1871}, abstract = {

The traditional logic of carbon (C) and nitrogen (N) interactions in ecosystems predicts further increases or decreases in productivity (positive feedback) in response to high and low fertility in the soil, respectively; but the potential for development of feedback in ecosystems recovering from disturbance is less well understood. Furthermore, this logic has been challenged in grassland ecosystems where frequent fires or grazing may reduce the contribution of aboveground litter inputs to soil organic matter pools and nutrient supply for plant growth, relative to forest ecosystems. Further, if increases in plant productivity increase soil C content more than soil N content, negative feedback may result from increased microbial demand for N making less available for plant growth. We used a field experiment to test for feedback in an establishing grassland by comparing aboveground net primary productivity (ANPP) and belowground pools and fluxes of C and N in soil with enriched, ambient, and reduced N availability. For eight years annual N enrichment increased ANPP, root N, and root tissue quality, but root C:N ratios remained well above the threshold for net mineralization of N. There was no evidence that N enrichment increased root biomass, soil C or N accrual rates, or storage of C in total, microbial, or mineralizable pools within this time frame. However, the net nitrogen mineralization potential (NMP) rate was greater following eight years of N enrichment, and we attributed this to N saturation of the microbial biomass. Grassland developing under experimentally imposed N limitation through C addition to the soil exhibited ANPP, root biomass and quality, and net NMP rate similar to the ambient soil. Similarity in productivity and roots in the reduced and ambient N treatments was attributed to the potentially high nitrogen-use efficiency (NUE) of the dominant C4 grasses, and increasing cover of legumes over time in the C-amended soil. Thus, in a developing ecosystem, positive feedback between soil N supply and plant productivity may promote enhanced long-term N availability and override progressive N limitation as C accrues in plant and soil pools. However, experimentally imposed reduction in N availability did not feed back to reduce ANPP, possibly due to shifts in NUE and functional group composition.

}, keywords = {LTER-KNZ}, doi = {10.1890/07-0417.1}, url = {https://esajournals.onlinelibrary.wiley.com/doi/abs/10.1890/07-0417.1}, author = {S.G. Baer and John M. Blair} } @phdthesis {KNZ001096, title = {Genesis and spatial distribution of uplandsoils in east central Kansas}, volume = {PhD Dissertation}, year = {2007}, pages = {1 -704}, school = {Kansas State University}, type = {Ph.D. Thesis}, address = {Manhattan, KS}, abstract = {

Upland soils in east central Kansas have a complex genesis, often contain one or more paleosols, and form in multiple parent materials including loess, colluvium, residuum, and alluvium. Quaternary loess/paleosol investigations have largely ignored this region of Kansas, as the total loess thickness on uplands is \<2 m thick. In this study, the objectives are to examine the morphology and genesis of the soils of interest and how these characteristics vary within soil profiles, across landscapes, and throughout the current series mapping extent. The series of interest include the Irwin, Konza, Dwight, and Ladysmith soil series. Methods used in this study include field descriptions and sampling, terrain analysis, micromorphological investigations, and laboratory characterization, including silt and clay mineralogy. Accelerator mass spectrometry (AMS) was used for numerical dating and determination of stable carbon isotope values (δ13C) for selected paleosols. Radiocarbon ages ranged from 24,000 to 19,000 yr BP and δ13C values were between -19 and -17 \‰ (PDB), indicating that the paleosols were formed in Gilman Canyon loess or the Severance formation, under a mix of C3 and C4 vegetation. Terrain analysis results illustrated that, in given drainage areas, the soil series were mapped on a wide range of slope positions. Field observations and terrain analysis confirmed no relationships between mollic epipedon thickness, solum thickness, paleosol thickness, or depth to the paleosol with respect to landform. Micromorphological investigations revealed increasing soil development with depth, i.e., the presence of two paleosols beneath the modern soil. Mean particle size and mineralogy vary geographically within individual series. Pedogenic carbonate accumulations and redoximorphic concentrations are common features of the soils of interest, and less common features include sodium and gypsum accumulations, slickensides, and redoximorphic depletions. Results from this study will be provided to the USDA-NRCS for use in future soil survey updates, and will contribute to Quaternary loess/paleosol knowledge in Kansas and the Great Plains.

}, keywords = {LTER-KNZ, genesis, kansas, Loess, mapping, Paleosols, soil}, url = {http://hdl.handle.net/2097/288 }, author = {Presley, D.R.} } @article {KNZ001146, title = {Global-scale similarities in nitrogen release patterns during long-term decomposition}, journal = {Science}, volume = {315}, year = {2007}, pages = {361 -364}, abstract = {Litter decomposition provides the primary source of mineral nitrogen (N) for biological activity in most terrestrial ecosystems. A 10-year decomposition experiment in 21 sites from seven biomes found that net N release from leaf litter is dominantly driven by the initial tissue N concentration and mass remaining regardless of climate, edaphic conditions, or biota. Arid grasslands exposed to high ultraviolet radiation were an exception, where net N release was insensitive to initial N. Roots released N linearly with decomposition and exhibited little net N immobilization. We suggest that fundamental constraints on decomposer physiologies lead to predictable global-scale patterns in net N release during decomposition.}, keywords = {LTER-KNZ}, doi = {10.1126/science.1134853}, author = {Parton, W.J. and Silver, W.L. and Burke, I.C. and Grassens, L. and Harmon, M.E. and Currie, W.S. and King, J.Y. and Adair, E.C. and Brandt, L.A. and Hart, S.C. and Fasth, B.} } @article {KNZ001098, title = {Grasshopper (Orthoptera: Acrididae) communities respond to fire, bison grazing and weather in North Americantallgrass prairie: A long-term study}, journal = {Oecologia}, volume = {153}, year = {2007}, pages = {699 -711}, abstract = {

Because both intrinsic and extrinsic factors influence insect population dynamics, operating at a range of temporal and spatial scales, it is difficult to assess their contributions. Long-term studies are ideal for assessing the relative contributions of multiple factors to abundance and community dynamics. Using data spanning 25 years, we investigate the contributions of weather at annual and decadal scales, fire return interval, and grazing by bison to understand the dynamics of abundance and community composition in grasshopper assemblages from North American continental grassland. Each of these three primary drivers of grassland ecosystem dynamics affects grasshopper population and community dynamics. Negative feedbacks in abundances, as expected for regulated populations, were observed for all feeding guilds of grasshoppers. Abundance of grasshoppers did not vary in response to frequency of prescribed burns at the site. Among watersheds that varied with respect to controlled spring burns and grazing by bison, species composition of grasshopper assemblages responded significantly to both after 25 years. However, after more than 20 years of fire and grazing treatments, the number of years since the last fire was more important than the managed long-term fire frequency per se. Yearly shifts in species composition (1983\–2005), examined using non-metric multidimensional scaling and fourth-corner analysis, were best explained by local weather events occurring early in grasshopper life cycles. Large-scale patterns were represented by the Palmer Drought Severity Index and the North Atlantic Oscillation (NAO). The NAO was significantly correlated with annual mean frequencies of grasshoppers, especially for forb- and mixed-feeding species. Primary grassland drivers\—fire, grazing and weather\—contributing both intrinsic and extrinsic influences modulate long-term fluctuations in grasshopper abundances and community taxonomic composition.

}, keywords = {LTER-KNZ, Fire frequency, Insect populations, Konza Prairie, Long-Term Ecological Research Program, Weather}, doi = {10.1007/s00442-007-0761-8}, url = {https://link.springer.com/article/10.1007/s00442-007-0761-8}, author = {Jonas, J.L. and Anthony Joern} } @article {KNZ001070, title = {Growth responses of twodominant C4 grass species to altered water availability}, journal = {InternationalJournal of Plant Sciences}, volume = {167}, year = {2006}, pages = {1001 -1010}, abstract = {Identifying key ecophysiological traits that differ among dominant plant species and can be linked to species-specific responses to drought would improve our ability to forecast community and ecosystem responses to global climate change. The mesic grasslands of the central plains of North America are dominated by two C4 grass species, Andropogon gerardii and Sorghastrum nutans, which purportedly differ in their tolerance of water stress. Individuals of these two species were grown in the field under rain-out shelters and subjected to wet (watered every 2{\textendash}3 d) or dry (repeatedly subjected to wilting before watering) soil moisture regimes. A range of ecophysiological traits potentially important for tolerating water stress were concurrently measured. Although few traits differed between the species in the wet treatment, several traits were identified in the dry treatment that may enable A. gerardii to better tolerate drought. These were greater allocation to roots, reduced allocation to flowering, more rapid leaf turnover, and more rapid recovery of photosynthesis after wilting. The latter two traits may be particularly important for coping with increased variability in rainfall regimes in the future and are consistent with recently documented responses of A. gerardii to experimental increases in soil moisture variability.}, keywords = {LTER-KNZ, Andropogon gerardii, biomass allocation, Climate change, leaf turnover, photosynthesis, Sorghastrum nutans, water stress}, doi = {10.1086/505611}, author = {Swemmer, A.M. and Alan K. Knapp and M.D. Smith} } @article {KNZ00992, title = {Geographic variation in Brown-headed Cowbird (Molothrus ater) parasitism on Dickcisssels (Spiza americana) in Great Plains tallgrass prairie}, journal = {Auk}, volume = {122}, year = {2005}, pages = {648 -660}, abstract = {The incidence of brood parasitism by Brown-headed Cowbirds (Molothrus ater; hereafter {\textquotedblleft}cowbirds{\textquotedblleft}) within host species typically reflects the continental pattern in cowbird abundance across North America, where parasitism is heaviest in the Great Plains. However, we found considerable variation in cowbird parasitism on Dickcissel (Spiza americana) nests within a subregion of the Great Plains (the Flint Hills), where the highest levels of cowbird parasitism on grassland bird nests had been previously reported. Local parasitism frequencies on Dickcissel nests varied latitudinally across the Flint Hills, ranging from 0\% to 92\% of nests parasitized. Interestingly, we found no obvious patterns in habitat or host attributes that were associated with this steep geographic gradient in brood parasitism. Cowbird parasitism on Dickcissel nests was not correlated with the vertical density of local prairie vegetation, mean nest distance to edge, proportion of forest to grassland habitat surrounding study sites (<=5 to 10 km), geographic variation in host abundance, or Dickcissel density or nest initiation dates. Parasitism frequencies and intensities (number of cowbird eggs per parasitized nest) on Dickissel nests were only significantly related to variation in local female cowbird density. Dickcissel clutch size and apparent fledging success were negatively correlated with local cowbird parasitism levels. Geographic patterns in cowbird abundance within and among regions should be considered when establishing conservation areas for grassland birds or other cowbird hosts of concern.}, keywords = {LTER-KNZ, brood parasitism, brown-headed cowbird, Dickcissel, geographic variation, Molothrus ater, Spiza americana}, doi = {10.1642/0004-8038(2005)122[0648:GVIBCM]2.0.CO;2}, author = {Jensen, W.E. and Cully, J.F.} } @article {KNZ00943, title = {Generality in ecology: testing North American grassland rules in South African savannas}, journal = {Frontiers in Ecology and the Environment}, volume = {9}, year = {2004}, pages = {483 -491}, abstract = {Ecology has emerged as a global science, and there is a pressing need to identify ecological rules {\textendash} general principles that will improve its predictive capability for scientists and its usefulness for managers and policy makers. Ideally, the generality and limits of these ecological rules should be assessed using extensive, coordinated experiments that ensure consistency in design and comparability of data. To improve the design of these large-scale efforts, existing data should be used to test prospective ecological rules and to identify their limits and contingencies. As an example of this approach, we describe prospective rules for grassland responses to fire and rainfall gradients, identified from long-term studies of North American grasslands and tested with existing data from long-term experiments in South African savanna grasslands. Analyses indicated consistent effects of fire on the abundance of the dominant (grasses) and subdominant (forbs) flora on both continents, but no common response of grass or forb abundance across a rainfall gradient. Such analyses can inform future research designs to refine and more explicitly test ecological rules.}, keywords = {LTER-KNZ}, doi = {10.1890/1540-9295(2004)002[0483:GIETNA]2.0.CO;2}, author = {Alan K. Knapp and M.D. Smith and Scott. L. Collins and Zambatis, N. and Peel, M. and Emery, S.M. and Wojdak, J. and Horner-Devine, M.C. and Biggs, H. and Kruger, J. and Andelman, S.J.} } @article {KNZ00955, title = {Gibberella konza (Fusarium konzum) sp nov from prairie grasses, a new species in the Gibberella fujikuroi species complex}, journal = {Mycologia}, volume = {95}, year = {2004}, pages = {943 -954}, abstract = {The Gibberella fujikuroi species complex (Fusarium section Liseola and allied taxa) is composed of an increasingly large number of morphological, biological and phylogenetic species. Most of the known species in this group have been isolated from agricultural ecosystems or have been described from a small number of isolates. We sampled Fusarium communities from native prairie grasses in Kansas and recovered a large number of isolates that superficially resemble F. anthophilum. We used a combination of morphological, biological and molecular characters to describe a new species, Gibberella konza (Gibberella fujikuroi mating population I [MP-I]), from native prairie grasses in Kansas. Although female fertility for field isolates of this species appears to be low, G. konza is heterothallic, and we developed reliably female fertile mating population tester strains for this species. The F. konzum anamorph is differentiated from F. anthophilum and from other Fusarium species in section Liseola by mating compatibility, morphology, AFLP fingerprint profile and differences in β-tubulin DNA sequence.}, keywords = {LTER-KNZ, AFLP, biological species, DNA sequence, Fusarium anthophilum, mating population, β-tubulin}, url = {http://www.mycologia.org/content/95/5/943.short}, author = {Zeller, K.A. and Summerell, B.A. and Bullock, S. and Leslie, J.F.} } @phdthesis {KNZ00958, title = {Granivory in the prairie of central North America}, volume = {PhD Dissertation}, year = {2004}, pages = {1 -111}, school = {Kansas State University}, type = {Ph.D. Thesis}, address = {Manhattan, KS}, keywords = {LTER-KNZ}, author = {Reed, A.W.} } @article {KNZ00879, title = {Grazing management effects on plant species diversity in tallgrass prairie}, journal = {Journal of Range Management}, volume = {57}, year = {2004}, pages = {58 -65}, abstract = {A 6-year study was conducted in tallgrass prairie to assess the effects of grazing management (cattle stocking densities and grazing systems) on plant community composition and diversity. Treatments included sites grazed season-long (May to October) at 3 stocking densities (3.8, 2.8, and 1.8 hectares per animal unit), ungrazed control sites, and sites under a late-season rest rotation grazing system at this same range of stocking densities. Plant communities were sampled twice each season using a nearest-point procedure. Native plant species diversity, species richness, and growth form diversity were significantly higher in grazed compared to ungrazed prairie, and diversity was greatest at the highest stocking density. This enhancement of plant species diversity under grazing was not a result of increased frequency of weedy/exotic species. There were no significant effects of grazing system on plant diversity, nor any significant stocking density {\texttimes} grazing system interactions, indicating that animal density is a key management variable influencing plant species diversity and composition in tallgrass prairie and that effects of animal density override effects of grazing systems. Increasing cattle stocking densities decreased the abundance of the dominant perennial tall grasses, and increased abundance of the C4 perennial mid-grasses. The frequency of perennial forbs was relatively stable across grazing treatments. Abundance of annual forbs varied among years and grazing treatments. In half of the years sampled, annual forbs showed the highest frequency under intermediate stocking density. Patterns of responses among plant groups suggest that some species may respond principally to direct effects of grazers and others may respond to indirect effects of grazers on competitive relationships or on the spatial patterns of fuel loads and fires. Thus, this study suggests that large grazer densities, fire, and annual climatic variability interact to influence patterns of plant community composition and diversity in tallgrass prairie. Effects of varying management such as stocking densities and grazing systems on plant species diversity and the relative abundances of different plant growth forms or functional groups may have important consequences for grassland community stability and ecosystem function.}, keywords = {LTER-KNZ, Biodiversity, cattle grazing, Flint Hills, grazing systems, plant ecology, range management, stocking rates}, doi = {10.2111/1551-5028(2004)057[0058:GMEOPS]2.0.CO;2}, author = {Hickman, K.R. and D.C. Hartnett and Cochran, R.C. and Owensby, C.E.} } @inbook {KNZ00836, title = {Grasslands of the North American Great Plains}, booktitle = {Phenology: An Integrative Environmental Science}, year = {2003}, pages = {157 -174}, publisher = {Kluwer}, organization = {Kluwer}, address = {New York}, abstract = {The study of appearances of growth, development, and senescence in grassland communities is not an enterprise commonly pursued. Phenology of mid-latitude grasslands is, nevertheless, too large and diverse a collection of phenomena to cover within a single chapter, as it ought to embrace at once the vast Kazakh steppe, the chalk grasslands of southern England, and myriad other grassy landscapes. Thus, the view here shall be on the grasslands of the North American Great Plains, with particular reference to the tallgrass prairie as a type model.}, keywords = {LTER-KNZ, Anthesis, Great Plains, tallgrass prairie, transient maxima hypothesis}, url = {http://link.springer.com/chapter/10.1007/978-94-007-0632-3_11}, author = {Henebry, G.M.}, editor = {Schwartz, M.D.} } @article {KNZ00823, title = {Genetic diversity and competitive abilities of Dalea purpurea (Fabaceae) from remnant and restored grasslands}, journal = {International Journal of Plant Science}, volume = {163}, year = {2002}, pages = {979 -990}, abstract = {Allozyme and randomly amplified polymorphic DNA (RAPD) analyses were used to characterize the genetic relationships of Dalea purpurea from remnant and restored Illinois tallgrass prairies and a large remnant tallgrass prairie in Kansas. The remnant Illinois populations were less genetically diverse than the restored Illinois populations and the Kansas population. These restored Illinois populations were established with at least two seed sources that were locally collected. There was little population divergence ( ), which is consistent with other perennial forbs, while the genetic relationships among populations reflected geographic proximity. In a greenhouse competition experiment, differences in performance between seedlings was not related to the remnant or restored status of Illinois populations, but plants from Kansas were significantly smaller than Illinois plants. Genetic diversity and competitive ability were not associated with the size of the original source population. Our data indicate that using multiple local seed sources for restoration projects will maintain the local gene pool while enhancing the regional genetic diversity of this species.}, keywords = {LTER-KNZ, conservation genetics, local seed source, restoration ecology, tallgrass prairie}, doi = {10.1086/342709}, author = {Gustafson, D.J. and D.J. Gibson and Nickert, D.L.} } @mastersthesis {KNZ00764, title = {Gallery forest expansion in tallgrass prairie: mechanisms facilitating oak seedling and juvenile success}, volume = {MS Thesis}, year = {2001}, pages = {1 -75}, school = {Kansas State University}, type = {M.S. Thesis}, address = {Manhattan, KS}, keywords = {LTER-KNZ, tallgrass prairie}, author = {Danner, B.T.} } @article {KNZ00763, title = {Growth dynamics of gallery forest oak seedlings (Quercus macrocarpa Michx. and Quercus muhlenbergii Engelm.) from gallery forests: implications for forest expansion into grasslands}, journal = {Trees}, volume = {15}, year = {2001}, pages = {271 -277}, abstract = {Seedling growth dynamics of Quercus macrocarpa Michx. and Quercus muhlenbergii Engelm. were compared over a 3-month period under optimal growth conditions. These two species are the dominant trees at the western limit of the eastern deciduous forest, and are typically confined to gallery forests along stream beds in tallgrass prairie. Since tallgrass prairie is characterized by a highly variable climate and is prone to periodic drought, we hypothesized that these oaks would have rapid root growth and produce deep taproots as seedlings, enabling them to avoid drought stress and persist in this region. These traits may also facilitate forest expansion into the more xeric tallgrass prairie if fires are suppressed. Taproots of Q. macrocarpa and Q. muhlenbergii grew to approximately 140 cm and 100 cm in length, respectively, after 104 days. In both species, 65\% or more of seedling biomass was allocated below ground, and root/total biomass was significantly greater in Q. muhlenbergii at 0{\textendash}20 and 21{\textendash}40 days after germination. The seedling taproot elongation rates reported here are much greater than rates reported in other eastern deciduous forest trees. Long-term precipitation data and soil moisture patterns from tallgrass prairie, when combined with rapid taproot elongation rates, suggest that soil moisture may not limit oak establishment or growth in tallgrass prairie in most years, although water uptake by roots was not measured in this study. Other factors, such as fire, herbivory, and seed predation and dispersal may be equally important in constraining the distribution of these species to gallery forests.}, keywords = {LTER-KNZ, Gallery forests, Quercus, Seedling, Taproot}, doi = {10.1007/s004680100103}, author = {Danner, B.T. and Alan K. Knapp} } @phdthesis {KNZ00736, title = {Genetic and competition studies of Andropogon gerardii , Sorghastrum nutans and Dalea purpurea from remnant and restored tallgrass prairies}, volume = {PhD Dissertation}, year = {2000}, pages = {1 -228}, school = {Southern Illinois University}, type = {Ph.D. Thesis}, address = {Carbondale, IL}, keywords = {LTER-KNZ}, author = {Gustafson, D.J.} } @inbook {KNZ00657, title = {Geomorphology of the Konza Prairie}, booktitle = {Grassland Dynamics: Long-Term Ecological Research in Tallgrass Prairie}, year = {1998}, pages = {35 -47}, publisher = {Oxford University Press}, organization = {Oxford University Press}, address = {New York}, keywords = {LTER-KNZ, tallgrass prairie}, author = {Oviatt, C.G.}, editor = {Alan K. Knapp and J. M. Briggs and D.C. Hartnett and Scott. L. Collins} } @book {KNZ001010, title = {Grassland Dynamics: Long-Term Ecological Research in Tallgrass Prairie}, year = {1998}, pages = {364 -364}, publisher = {Oxford University Press}, organization = {Oxford University Press}, address = {New York}, keywords = {LTER-KNZ, tallgrass prairie}, author = {Alan K. Knapp and J. M. Briggs and D.C. Hartnett and Scott. L. Collins} } @inbook {KNZ00652, title = {Grasslands, Konza Prairie and long-term ecological Research}, booktitle = {Grassland Dynamics: Long-Term Ecological Research in Tallgrass Prairie}, year = {1998}, pages = {3 -15}, publisher = {Oxford University Press}, organization = {Oxford University Press}, address = {New York}, keywords = {LTER-KNZ, tallgrass prairie}, author = {Alan K. Knapp and Seastedt, T.R.}, editor = {Alan K. Knapp and J. M. Briggs and D.C. Hartnett and Scott. L. Collins} } @article {KNZ00593, title = {Gradient models, gradient analysis and hierarchical structure in plant communities}, journal = {Oikos}, volume = {78}, year = {1997}, pages = {23 -30}, abstract = {Two general models of plant community structure, the community-unit and the continuum, have dominated the thinking of American community ecologists. Hypotheses derived from these and other models of plant community structure rarely have been tested, however. Traditionally, analyses of gradient structure have focused primarily on whether or not the boundaries of species response curves are clustered, which does not provide a complete picture of gradient structure. In this study, we statistically analyzed three characteristics of plant community structure along gradients (1) pattern of boundaries of species distributions, (2) pattern of modes of species response curves, and (3) whether or not species distributions exhibit hierarchical structure. In combination, these characteristics yield eight different models of vegetation structure along gradients. To determine if vegetation corresponds to any of these models, we sampled species composition using belt transects of contiguous quadrats in a total of 42 wetland sites in Minnesota and the southern Great Plains, USA. Boundaries of species distributions were clustered in 10 of 42 cases, modes of species response curves were clustered in 19 of 42 cases, and species distributions exhibited hierarchical structure in all 42 cases. Results varied between sites. Overall, four models of community structure were supported. None of the sites sampled supported the models often associated with the continuum or the community-unit. These results confirmed the need to explore alternative models of gradient structure, and suggested that more than one model of vegetation structure may be needed to represent community structure along gradients.}, keywords = {LTER-KNZ}, doi = {10.2307/3545796}, author = {Hoagland, B.W. and Scott. L. Collins} } @mastersthesis {KNZ00575, title = {Genesis and morphology of soils on the Konza Prairie Research Natural Area, Riley and Geary Counties, KS}, volume = {MS Thesis}, year = {1996}, pages = {1 -166}, school = {Kansas State University}, type = {M.S. Thesis}, address = {Manhattan, KS}, abstract = {

The Konza Prairie Research Natural Area (KPRNA) is a 3487 ha tract of tallgrass prairie set aside for long-term ecological research. The purpose of this study is to describe the morphology of soils, investigate processes of soil genesis, and record the distribution of soils for one watershed (N4D) within KPRNA. The soils for the N4D watershed are mapped at a scale of 1:2,000. The soil map depicts the aerial distribution of soils in the study area. In the study area, there are four soil-landscape associations: (1) soils on the less sloping summits; (2) steeply sloping soils on side slopes; (3)soils on foot slopes; and (4) soils on terraces and flood plains. Parent material stratigraphy is much more complex than previous studies had shown. Soils on Summits developed in a thin mantle of loess overlying welded paleosols formed in hillslope sediment over residuum from Permian cherty limestone. The dominant pedogenic processes in the composite modern soil and paleosol formed in hillslope sediment are leaching of carbonate and translocation of clay resulting in formation of an argillic horizon. The extent of weathering observed in the paleosol suggests a longer period of soil formation than that of the composite modern soil and paleosol formed in hillslope sediment. Soils on side slopes have formed in hillslope sediment over residuum weathered from shale. On the steeply sloping side slopes, the soils exhibit no evidence of clay translocation. The lack of clay translocation and abundance of carbonates indicate that these soils are not highly weathered. Translocation and redistribution of carbonate was the dominant pedogenic process. In contrast, soils developed in similar parent materials on more gently sloping side slopes are leached more deeply and have argillic horizons. Soils on foot slopes have also formed in hillslope sediment over residuum. The depth to the lithologic discontinuity between the hillslope sediment and residuum is deeper for the soils on foot slopes compared to soils on side slopes. For soils on foot slopes, the dominant pedogenic process involves the translocation of clay and subsequent formation of an argillic horizon. There are multiple levels of terraces and flood plains in the study area. The parent material is alluvium. Buried soils on both terraces and flood plains suggest periods of stability and soil formation followed by periods of additional deposition. The dominant pedogenic processes have been organic matter accumulation and redistribution of carbonates.

}, keywords = {LTER-KNZ}, url = {http://www.agronomy.k-state.edu/events/national_collegiate_soils_contest/Wehmueller\%20MS\%20Thesis\%201996\%20Selected\%20Pages.pdf}, author = {Wehmueller, W.A.} } @inbook {KNZ00565, title = {Global grassland ecosystem modelling: development and test of ecosystem models for grassland systems}, booktitle = {Global Change: Effects on Coniferous Forests and Grasslands}, year = {1996}, pages = {229 -270}, publisher = {Wiley and Sons}, organization = {Wiley and Sons}, address = {Chichester}, keywords = {LTER-KNZ}, author = {Parton, W.J. and Coughenour, M.B. and Scurlock, J.M.O. and Ojima, D.S. and Gilmanov, T.G. and Scholes, R.J. and Schimel, D.S. and Kirchner, T.B. and Menaut, J.C. and Seastedt, T.R. and Moya, E.G. and Kamnalrut, A. and Kinyamario, J.I. and Hall, D.O.}, editor = {Breymeyer, A.I. and Hall, D.O. and Melillo, J.M. and Agren, G.I.} } @proceedings {KNZ00501, title = {Gas exchange and reproduction of Spiranthes vernalis (Orchidaceae) in a Kansas tallgrass prairie}, year = {1995}, pages = {21 -24}, keywords = {LTER-KNZ, tallgrass prairie}, url = {http://images.library.wisc.edu/EcoNatRes/EFacs/NAPC/NAPC14/reference/econatres.napc14.sjohnson.pdf}, author = {Johnson, S.R.}, editor = {D.C. Hartnett} } @article {KNZ00507, title = {Gas exchange characteristics of Typha latifolia L. from nine sites across North America}, journal = {Aquatic Biology}, volume = {49}, year = {1995}, pages = {203 -215}, abstract = {Gas exchange characteristics were measured in the field for nine populations of Typha latifolia L. from Florida to Minnesota in North America. These populations spanned a substantial gradient in growing season length and environmental conditions. The purpose of this study was to assess geographic variability in stomatal conductance (gst) in T. latifolia populations, as well as to identify key environmental and plant factors that may affect gst and, potentially, trace gas emissions through stomata. Midday rates of net photosynthesis (A) and gst were measured under full sunlight conditions at each site, and more intensive measurements of diurnal and seasonal variability were made at selected sites. In general, A varied less than gst (1.5 vs. 3 fold) among sites with maximum A (27.4 μmol m-2 s-1) and gst (1076.7 mmol m-2 s-1) measured at the southern sites. We found that A and gst in T. latifolia increased significantly with increasing temperature and light level, and varied diurnally and seasonally. Moreover, stomata closed completely at night, in contrast to some other wetland plants. Both A and gst also increased significantly along the length of leaves from the base of plants to the upper canopy. Finally, although gst was quite variable, A did not appear to be limited by gst under typical field conditions. It was concluded that generalizations that stomata in wetland plants are relatively unresponsive to environmental factors are not consistent with field responses measured in T. latifolia. As a result, because gst may influence trace gas flux in this species, spatial and temporal variations in gst need to be considered when emissions are estimated.}, keywords = {LTER-KNZ}, doi = {10.1016/0304-3770(94)00433-M}, author = {Alan K. Knapp and Yavitt, J.B.} } @mastersthesis {KNZ00515, title = {Geomorphology of the N4D watershed, Konza Prairie Research Natural Area, Riley and Geary Counties, Kansas}, volume = {MS Thesis}, year = {1995}, pages = {1 -60}, school = {Kansas State University}, type = {M.S. Thesis}, address = {Manhattan, KS}, keywords = {LTER-KNZ}, author = {Ross, K.L.} } @inbook {KNZ00483, title = {Grassland ecosystem and landscape dynamics}, booktitle = {The Changing Prairie}, year = {1995}, pages = {128 -156}, publisher = {Oxford University Press}, organization = {Oxford University Press}, keywords = {LTER-KNZ}, author = {Scott. L. Collins and Glenn, S.M.}, editor = {Anthony Joern and Keeler, K.K.} } @article {KNZ00398, title = {Gallwasp (Hymenoptera: Cynipidae) mortality in a spring tallgrass prairie fire}, journal = {Environmental Entomology}, volume = {22}, year = {1993}, pages = {1333 -1337}, abstract = {The life history of the cynipid gall wasp, Antistrophus silphii Gillette, leaves it vulnerable to mortality in spring fires in the habitat of its host plant, Silphium integrifolium var. laeve Torrey and Gray. This article examines the mortality of gall wasp larvae during a prescribed bum at the Konza Prairie Research Natural Area in the tallgrass prairie of northeast Kansas. The three goals of the study were to determine (1) if A: silphii galls are most frequently found on the tallest S. integrifolium shoots, (2) if there is a relationship between growing season gall height and overwinter lodging, and (3) if gall wasps can survive fire at the heights at which they are found after overwinter lodging. A 1988 survey found that galls were relatively rare on short shoots (<100 cm), were most abundant on middle-length shoots (100{\textendash}140 cm), and occurred at random on long shoots (>140 cm), suggesting that gall wasps avoided short shoots but that gall placement did not maximize gall height. A 1992 survey found that growing season gall height was not related to overwinter lodging of galled shoots, indicating that any gall wasp shoot selection patterns affecting later gall height were disrupted by winter lodging. Gall wasps placed at post-overwinter lodging heights were unable to survive an experimental fire, but a few gall wasps survived when placed above the range of naturally-occurring gall heights. A. silphii and other species with similar life histories must re-establish after fire by immigration, with subsequent population levels affected by indirect effects of fire on host-plant quality.}, keywords = {LTER-KNZ, Antistrophus silphii, fire, mortality}, doi = {http://dx.doi.org/10.1093/ee/22.6.1333 }, author = {Fay, P.A. and Samenus, R.J.J.} } @article {KNZ00412, title = {Gas exchange dynamics in C3 and C4 grasses: consequences of differences in stomatal conductance}, journal = {Ecology}, volume = {74}, year = {1993}, pages = {113 -123}, abstract = {In full sunlight (photosynthetic photon flux density, 0.4{\textemdash}0.7. μm, PPFD), stomatal conductance to water vapor (g) and transpiration rates (E) are usually higher, and water use efficiency lower, in C3 than C4 species. In the C3 grass Bromus inermis, the difference in conductance between full sun (photosynthetic photon flux [PPFD] > 1500 μmol{\textdegree}m{\textemdash}2{\textdegree}S{\textemdash}1) and shade (PPFD {\textdegree} 400 μmol{\textdegree}m{\textemdash}2{\textdegree}s{\textemdash}1) was twice as large as in the C4 species Sorghastrum nutans (226.7 vs. 97.8 mmol.m{\textemdash}2.S{\textemdash}1, respectively). Similar differences were measured in four additional C3 and C4 grasses. Variability in PPFD incident on leaves is very common in grasslands, and stomata are known to respond relatively rapidly to fluctuations in this resource. This study evaluated the consequences of different responses in stomatal conductance between C3 and C4 grasses during periods of sunlight variability. Photosynthesis (A, measured as CO2 uptake) and g varied substantially in both B. inermis and S. nutans as PPFD fluctuated between sun and shade levels (4{\textemdash}10 min intervals). Time constants derived form first{\textemdash}order equations describing responses in g after abrupt changes in PPFD indicated that g approached steady{\textemdash}state levels more rapidly in S. nutans than in B. inermis. However, because of the greater magnitude of change in g between sun and shade PPFD in B. inermis, the absolute rate of change in g in this C3 grass was twice as rapid compared to S. nutans (25.7 vs. 12.4 mmol{\textdegree}m{\textemdash}2{\textdegree}s{\textemdash}1{\textdegree}min{\textemdash}1 for reductions in g, respectively). New steady{\textemdash}state levels in g were achieved in 12{\textemdash}13 min after a change in PPFD in S. nutans and 15{\textemdash}19 min in B. inermis. A statistically based two{\textemdash}state (sun/shade) simulation model was used to quantify costs in A and E of the nonsteady{\textemdash}state responses measured for both species as PPFD varied. Costs were calculated as the difference between model output of A or E based on field responses and model output based on hypothetical gas exchange responses in which A and g changed instantaneously. Results suggested that even though the absolute rate of change in g changed was greater in the C3 grass, costs in E during periods of short{\textemdash}term (2{\textemdash}6 min) variations in PPFD were as much as sixfold higher than in the C4 species. Lower cost in E in C4 species during periods of variable PPFD (due to inherently smaller alterations in g) is a previously unrecognized consequence of the C4 photosynthetic pathway. C4 species, and grasses in particular, often are most successful in high{\textemdash}PPFD, water{\textemdash}limited environments in which leaf{\textemdash}level variability in PPFD occurs daily from cloud cover and within{\textemdash}canopy shading. In these environments, stomatal responses that conserve water under nonsteady{\textemdash}state conditions may contribute significantly to the success of C4 species.}, keywords = {LTER-KNZ}, doi = {10.2307/1939506}, author = {Alan K. Knapp} } @book {KNZ00415, title = {GIS Applications in Mammalogy}, year = {1993}, pages = {41 -}, publisher = {Special Publication of the Oklahoma Museum of Natural History}, organization = {Special Publication of the Oklahoma Museum of Natural History}, keywords = {LTER-KNZ}, author = {McLaren, S.B. and J. Brown} } @article {KNZ00372, title = {Geographic information systems for modeling bison impact on Konza Prairie, Kansas}, journal = {GIS/LIS Proceedings}, volume = {2}, year = {1992}, pages = {618 -623}, keywords = {LTER-KNZ, Information Systems}, author = {Nellis, M.D. and J.D. Bathgate and J. M. Briggs} } @article {KNZ00365, title = {Geographic variation in length of tail of white-footed mice (Peromyscus leucopus) in Kansas}, journal = {Journal of Mammalogy}, volume = {73}, year = {1992}, pages = {789 -793}, keywords = {LTER-KNZ}, doi = {10.2307/1382196~}, author = {Kaufman, D.M. and D.W. Kaufman} } @proceedings {KNZ00369, title = {Ground-water chemistry under tallgrass prairie, Central Kansas, USA}, year = {1992}, pages = {809 -812}, keywords = {LTER-KNZ, tallgrass prairie}, author = {G. L. Macpherson}, editor = {Kharaka, Y.K. and Maest, A.S.} } @phdthesis {KNZ00356, title = {The growth and physiological responses of Silphium integrifolium to gall insect attack}, volume = {PhD Dissertation}, year = {1992}, pages = {1 -102}, school = {Kansas State University}, type = {Ph.D. Thesis}, address = {Manhattan, KS}, keywords = {LTER-KNZ, insect}, author = {Fay, P.A.} } @article {KNZ00373, title = {Growth and transition: Remote sensing and geographic information systems at Kansas State University}, journal = {Photogrammetric Engineering and Remote Sensing}, volume = {58}, year = {1992}, pages = {1159 -1161}, abstract = {

Remote sensing and geographic information systems education and research at Kansas State University have grown tremendously in the past decade. Dramatic improvements in hardware and software have enhanced offerings in a wide range of spatial analysis (including remote sensing) courses. Success in extramural funding through such agencies as the U.S. Agency for International Development and the National Science Foundation have created a major research thrust in Kansas State University\&$\#$39;s Geography and Biology programs relative to the application of remote sensing and geographic information systems for natural resource assessment and landscape ecology. The State of Kansas initatives have also enhanced Kansas State University\&$\#$39;s role in providing a significant contribution in remote sensing/geographic information systems research and education

}, keywords = {LTER-KNZ, Information Systems}, author = {Nellis, M.D. and J. M. Briggs and Seyler, H.L.} } @mastersthesis {KNZ00339, title = {Geomorphology and geomorphic history of the Konza Prairie Research Natural Area, Riley and Geary Counties, Kansas}, volume = {MS Thesis}, year = {1991}, pages = {1 -121}, school = {Kansas State University}, type = {M.S. Thesis}, address = {Manhattan, KS}, keywords = {LTER-KNZ}, author = {Smith, G.N.} } @article {KNZ00304, title = {Glomus Mortonii sp. Nov., a previously undescribed species in the Glomaceae isolated from the tallgrass prairie in Kansas}, journal = {Mycotoxon}, volume = {42}, year = {1991}, pages = {9 -15}, keywords = {LTER-KNZ, tallgrass prairie}, author = {Bentivenga, S.P. and Hetrick, B.A.D.} } @proceedings {KNZ00325, title = {Grassland mammal communities and fire}, year = {1991}, publisher = {Region 6, Mountain-Prairie Region, United States Fish and Wildlife Service}, address = {Denver, CO}, keywords = {LTER-KNZ, fire}, author = {D.W. Kaufman and Kaufman, G.A.} } @article {KNZ00165, title = {Genetic variation in leaf morphology and plant and tissue water relations during drought in Cercis canadensis . L}, journal = {Forest Science}, volume = {34}, year = {1988}, pages = {200 -207}, abstract = {

Genetic variation in plant and tissue water relations in response to drought, and in leaf morphology, were examined in greenhouse-grown Cercis canadensis L. (eastern redbud) seedlings originating from seed obtained in three contrasting habitats: a relatively xeric Kansas prairie, a Kansas gallery forest understory, and a relatively mesic Indiana understory. Kansas prairie redbud maintained significantly greater leaf conductance (gwv) during a 13-day drought than did Kansas and Indiana understory redbud, despite similar decreases in leaf water potential in all three sources. Moreover, Kansas paririe redbud had significantly lower osmotic potentials at full and zero turgor compared to Indiana redbud at both the early and later stages of drought. Kansas understory redbud was the only source to undergo a signigicant decrease in relative water content at zero turgor and the bulk modulus of elasticity during drought. Kansas prairie redbud leaver were smaller and thicker and had higher specific leaf mass (i.e., more xerophytic) than understory redbud leaves. Kansas understory redbud had intermediate characteristics in terms of gwv at the early to middle stages of drought, osmotic potentials at high and low leaf water potential, and leaf area and thickness compared to Kansas prairie and Indiana understory redbud. These results suggest that genetically controlled physiological and morphological adaptation has occurred in redbud that should facilitate its survival in greatly contrasting habitats. ADDITIONAL KEY WORDS: Ecophysiology, Kansas prairie, gallery forest, Indiana understory, leaf morphology

}, keywords = {LTER-KNZ, Water relations}, author = {Abrams, M.D.} } @article {KNZ00172, title = {Grasshopper (Insecta: Orthoptera: Acrididae) assemblages of tallgrass prairie: influence of fire frequency, topography, and vegetation}, journal = {Canadian Journal of Zoology}, volume = {66}, year = {1988}, pages = {1495 -1501}, abstract = {

Grasshopper assemblages were sampled by sweep net in native tallgrass prairie at Konza Prairie, Kansas, in 1982-1986 to assess the influences of fire, topography, and vegetation on local species composition. Species composition at 38 sites was analyzed by ordination (detrended correspondence analysis). Frequency of fire and topographic location were reflected along the first two principal axes, respectively. Grass-feeding grasshoppers were more numerous than forb- and mixed-feeding grasshoppers throughout the prairie, but forb and mixed feeders became relatively more frequent as fire frequency decreased. Local species richness of grasshoppers was greater on sites burned infrequently than on sites burned annually or biennially, and on upland than on lowland sites. Local species richness was positively correlated with local plant species richness and diversity, reflecting in part that local relative abundance of forb-feeding grasshoppers was positively correlated with local relative abundance of forbs. Collectively these results are consistent in suggesting that through their effects on local plant communities, fire frequency and topography are major factors influencing the composition of local grasshopper assemblages in tallgrass prairie

}, keywords = {LTER-KNZ, tallgrass prairie}, doi = {10.1139/z88-219}, author = {Evans, E.W.} }