01657nam a2200169 4500008004100000020001800041022001800059245007700077210006900154250000600223260001300229300000800242520112400250100001801374700001701392856007801409 2019 eng d a9780128132562 a978012813255500aFreshwater ecology: concepts and environmental applications of limnology0 aFreshwater ecology concepts and environmental applications of li a3 bElsevier a9983 a

Description: Freshwater Ecology, Third Edition, covers everything from the basic chemical and physical properties of water, to the advanced and unifying concepts of community ecology and ecosystem relationships found in continental waters. Giving students a solid foundation for both courses and future fieldwork, and updated to include key issues, including how to balance ecological and human health needs, GMOs, molecular tools, fracking, and a host of other environmental issues, this book is an ideal resource for both students and practitioners in ecology and related fields.
Key Features: 1. Provides an updated revision of this classic text, covering both basic scientific concepts and environmental applications.
2. Includes additional biography boxes with greater cultural diversity of the featured scientists
3. Covers expanded content on developing nations, ecosystem goods and services, properties of water, global change, impacts of fracking, molecular tools for classification and identification of aquatic organisms, a discussion of emergent diseases and aquatic habitats, and more

1 aDodds, W., K.1 aWhiles, M.R. uhttps://www.elsevier.com/books/freshwater-ecology/dodds/978-0-12-813255-501898nas a2200193 4500008004100000245010400041210006900145300003000214490000700244520125400251100001701505700002201522700001401544700001601558700002201574700002301596700001501619856007001634 2019 eng d00aPeriodical cicada emergence resource pulse tracks forest expansion in a tallgrass prairie landscape0 aPeriodical cicada emergence resource pulse tracks forest expansi ae02779. 10.1002/ecs2.27790 v103 a

Understanding factors that influence resource pulses is an important aspect of ecosystem ecology. We quantified below‐ to aboveground energy and nutrient fluxes during the 2015 periodical cicada emergence from forest habitats in a tallgrass prairie matrix and compared results to our prior studies of the 1998 emergence in the same watershed. We estimated 35.2 million cicadas emerged across 159 ha in 2015, almost 2× more than the 19.6 million across 98 ha in 1998. The 2015 emergence resulted in below‐ to aboveground fluxes of 9.4 metric tons of ash‐free dry mass and 1.12 metric tons of N, both ~2× greater than 1998. This corresponds to 59 kg C/ha and 7 kg N/ha in and adjacent to forested areas in 2015. Increased emergence in 2015 was a result of spatial expansion of cicadas, not higher densities. Periodical cicadas are expanding with forest habitats in this region. Cicadas expand into and oviposit in ~40% of available forest habitat during each emergence. Accordingly, we predict the 2032 emergence will span ~245 ha. Our study demonstrates how human alterations to a landscape, in this case forest expansion linked to fire suppression and reduced grazing, can alter the magnitude and extent of a resource pulse.

1 aWhiles, M.R.1 aSnyder, Bruce, A.1 aBrock, B.1 aBonjour, S.1 aCallaham, Mac, A.1 aMeyer, Clinton, K.1 aBell, Alex uhttps://esajournals.onlinelibrary.wiley.com/doi/10.1002/ecs2.277902718nas a2200421 4500008004100000245009300041210006900134300001400203490000700217520145600224100001501680700001801695700001901713700001901732700002501751700001701776700002501793700002501818700002301843700002201866700002301888700002201911700001701933700002201950700002301972700002401995700002602019700002102045700002302066700002202089700002402111700002102135700002302156700001702179700002602196700002102222856005302243 2018 eng d00aContinental-scale decrease in net primary productivity in streams due to climate warming0 aContinentalscale decrease in net primary productivity in streams a415 - 4200 v113 a

Streams play a key role in the global carbon cycle. The balance between carbon intake through photosynthesis and carbon release via respiration influences carbon emissions from streams and depends on temperature. However, the lack of a comprehensive analysis of the temperature sensitivity of the metabolic balance in inland waters across latitudes and local climate conditions hinders an accurate projection of carbon emissions in a warmer future. Here, we use a model of diel dissolved oxygen dynamics, combined with high-frequency measurements of dissolved oxygen, light and temperature, to estimate the temperature sensitivities of gross primary production and ecosystem respiration in streams across six biomes, from the tropics to the arctic tundra. We find that the change in metabolic balance, that is, the ratio of gross primary production to ecosystem respiration, is a function of stream temperature and current metabolic balance. Applying this relationship to the global compilation of stream metabolism data, we find that a 1 °C increase in stream temperature leads to a convergence of metabolic balance and to a 23.6% overall decline in net ecosystem productivity across the streams studied. We suggest that if the relationship holds for similarly sized streams around the globe, the warming-induced shifts in metabolic balance will result in an increase of 0.0194 Pg carbon emitted from such streams every year.

1 aSong, Chao1 aDodds, W., K.1 aRüegg, Janine1 aArgerich, Alba1 aBaker, Christina, L.1 aBowden, W.B.1 aDouglas, Michael, M.1 aFarrell, Kaitlin, J.1 aFlinn, Michael, B.1 aGarcia, Erica, A.1 aHelton, Ashley, M.1 aHarms, Tamara, K.1 aJia, Shufang1 aJones, Jeremy, B.1 aKoenig, Lauren, E.1 aKominoski, John, S.1 aMcDowell, William, H.1 aMcMaster, Damien1 aParker, Samuel, P.1 aRosemond, Amy, D.1 aRuffing, Claire, M.1 aSheehan, Ken, R.1 aTrentman, Matt, T.1 aWhiles, M.R.1 aWollheim, Wilfred, M.1 aBallantyne, Ford uhttp://www.nature.com/articles/s41561-018-0125-506735nas a2200373 4500008004100000245012300041210006900164300000800233490000700241520565500248100001505903700001405918700001305932700002105945700002005966700001805986700001706004700001906021700001706040700002006057700001906077700001606096700002006112700001606132700001906148700001806167700001906185700001706204700001506221700001606236700001706252700001806269856007406287 2018 eng d00aPartitioning assimilatory nitrogen uptake in streams: an analysis of stable isotope tracer additions across continents0 aPartitioning assimilatory nitrogen uptake in streams an analysis a1380 v883 a

Headwater streams remove, transform, and store inorganic nitrogen (N) delivered from surrounding watersheds, but excessive N inputs from human activity can saturate removal capacity. Most research has focused on quantifying N removal from the water column over short periods and in individual reaches, and these ecosystem-scale measurements suggest that assimilatory N uptake accounts for most N removal. However, cross-system comparisons addressing the relative role of particular biota responsible for incorporating inorganic N into biomass are lacking. Here we assess the importance of different primary uptake compartments on reach-scale ammonium (NH4+-N) uptake and storage across a wide range of streams varying in abundance of biota and local environmental factors. We analyzed data from 17 15N-NH4+tracer addition experiments globally, and found that assimilatory N uptake by autotrophic compartments (i.e., epilithic biofilm, filamentous algae, bryophytes/macrophytes) was higher but more variable than for heterotrophic microorganisms colonizing detrital organic matter (i.e., leaves, small wood, and fine particles). Autotrophic compartments played a disproportionate role in N uptake relative to their biomass, although uptake rates were similar when we rescaled heterotrophic assimilatory N uptake associated only with live microbial biomass. Assimilatory NH4+-N uptake, either estimated as removal from the water column or from the sum uptake of all individual compartments, was four times higher in open- than in closed-canopy streams. Using Bayesian Model Averaging, we found that canopy cover and gross primary production (GPP) controlled autotrophic assimilatory N uptake while ecosystem respiration (ER) was more important for the heterotrophic contribution. The ratio of autotrophic to heterotrophic N storage was positively correlated with metabolism (GPP: ER), which was also higher in open- than in closed-canopy streams. Our analysis shows riparian canopy cover influences the relative abundance of different biotic uptake compartments and thus GPP:ER. As such, the simple categorical variable of canopy cover explained differences in assimilatory N uptake among streams at the reach scale, as well as the relative roles of autotrophs and heterotrophs in N storage. Finally, this synthesis links cumulative N uptake by stream biota to reach-scale N demand and provides a mechanistic and predictive framework for estimating and modeling N cycling in other streams.

1 aTank, J.L.1 aMarti, E.1 aRiis, T.1 avon Schiller, D.1 aReisinger, A.J.1 aDodds, W., K.1 aWhiles, M.R.1 aAshkenas, L.R.1 aBowden, W.B.1 aCollins, S., M.1 aCrenshaw, C.L.1 aCrowl, T.A.1 aGriffiths, N.A.1 aGrimm, N.B.1 aHamilton, S.K.1 aJohnson, S.L.1 aMcDowell, W.H.1 aNorman, B.M.1 aRosi, E.J.1 aSimon, K.S.1 aThomas, S.A.1 aWebster, J.R. uhttps://esajournals.onlinelibrary.wiley.com/doi/full/10.1002/ecm.128000518nas a2200121 4500008004100000245013700041210006900178260005600247490001400303100001600317700001700333856004600350 2017 eng d00aInfluence of fishes on stream invertebrate community structure and insect emergence from permanent pools in a prairie stream network0 aInfluence of fishes on stream invertebrate community structure a aCarbondale, IL 62901bSouthern Illinois University0 vMS Thesis1 aBonjour, S.1 aWhiles, M.R. uhttps://opensiuc.lib.siu.edu/theses/2348/03056nas a2200409 4500008004100000022001400041245011300055210006900168300001200237490000700249520184200256653001802098653001802116653001502134653001702149653001202166653002102178100001902199700001802218700001802236700002102254700002502275700001702300700002502317700002302342700002202365700001602387700002302403700002402426700001902450700002302469700002202492700002302514700001702537700002602554856006602580 2016 eng d a0921-297300aBaseflow physical characteristics differ at multiple spatial scales in stream networks across diverse biomes0 aBaseflow physical characteristics differ at multiple spatial sca a119-1360 v313 a

Context Spatial scaling of ecological processes is facilitated by quantifying underlying habitat attributes. Physical and ecological patterns are often measured at disparate spatial scales limiting our ability to quantify ecological processes at broader spatial scales using physical attributes. Objective We characterized variation of physical stream attributes during periods of high biological activity (i.e., baseflow) to match physical and ecological measurements and to identify the spatial scales exhibiting and predicting heterogeneity. Methods We measured canopy cover, wetted width, water depth, and sediment size along transects of 1st–5th order reaches in five stream networks located in biomes from tropical forest to arctic tundra. We used hierarchical analysis of variance with three nested scales (watersheds, stream orders, reaches) to identify scales exhibiting significant heterogeneity in attributes and regression analyses to characterize gradients within and across stream networks. Results Heterogeneity was evident at one or multiple spatial scales: canopy cover and water depth varied significantly at all three spatial scales while wetted width varied at two scales (stream order and reach) and sediment size remained largely unexplained. Similarly, prediction by drainage area depended on the attribute considered: depending on the watershed, increases in wetted width and water depth with drainage area were best fit with a linear, logarithmic, or power function. Variation in sediment size was independent of drainage area. Conclusions The scaling of ecologically relevant baseflow physical characteristics will require study beyond the traditional bankfull geomorphology since predictions of baseflow physical attributes by drainage area were not always best explained by geomorphic power laws.

10aBoreal forest10aGeomorphology10aGrasslands10aNested ANOVA10aScaling10aTemperate forest1 aRüegg, Janine1 aDodds, W., K.1 aDaniels, M.D.1 aSheehan, Ken, R.1 aBaker, Christina, L.1 aBowden, W.B.1 aFarrell, Kaitlin, J.1 aFlinn, Michael, B.1 aHarms, Tamara, K.1 aJones, J.B.1 aKoenig, Lauren, E.1 aKominoski, John, S.1 aMcDowell, W.H.1 aParker, Samuel, P.1 aRosemond, Amy, D.1 aTrentman, Matt, T.1 aWhiles, M.R.1 aWollheim, Wilfred, M. uhttps://link.springer.com/article/10.1007%2Fs10980-015-0289-y02612nas a2200169 4500008004100000245010100041210006900142300001600211490000700227520203500234100001702269700001802286700001702304700002202321700001802343856008102361 2016 eng d00aA before-and-after assessment of patch-burn grazing and riparian fencing along headwater streams0 abeforeandafter assessment of patchburn grazing and riparian fenc a1543–15530 v533 a
  1. Fire and grazing are common in grasslands world-wide to maintain grass cover and cattle production. The effects of fire, cattle grazing and riparian fencing efficacy on prairie stream ecology are not well characterized at catchment scales.
  2. We examined alterations to stream water quality and biology from patch-burn grazing (PBG) in tallgrass prairie during a five-year, replicated, catchment scale experiment that used a Before-After/Control-Impact (BACI) design and was analysed by mixed-effects models. Treatments included two patch-burned control catchments (fire but no grazers) and PBG in two riparian-fenced and two unfenced catchments. We assessed the effectiveness of riparian fencing for mitigating potential water quality impacts by monitoring water quality and riparian usage by cattle via Global Positioning System.
  3. Riparian fences effectively excluded cattle; however, in unfenced pastures, cattle aggregated along streams 10–20% of the grazing season.
  4. After initiation of PBG, we detected large increases in some nutrients, Escherichia coli, algal biomass, primary productivity and community respiration in all catchments with PBG. Some water quality variables, such as E. coli concentrations, recovered quickly after cattle were removed from pasture, which indicated resiliency.
  5. Riparian fencing moderately reduced the impacts to stream variables, indicating either overland flow and/or subsurface flow allowed nutrients and bacteria to enter the streams.
  6. Synthesis and applications. Patch-burn grazing is a measurable disturbance that can alter the ecological condition of streams. Riparian fencing lessened the degree of impact, yet some water quality variables still exceeded regional reference conditions. Managers will need to assess the costs of riparian fencing compared to the moderate benefits that fencing provides to water quality.
1 aLarson, D.M.1 aDodds, W., K.1 aWhiles, M.R.1 aThompson, T.R., .1 aFulgoni, J.N. uhttps://besjournals.onlinelibrary.wiley.com/doi/full/10.1111/1365-2664.1269202429nas a2200121 4500008004100000245012900041210006900170490000700239520196500246100002202211700001702233856005702250 2015 eng d00aEffects of experimental forest removal on macroinvertebrate production and functional structure in tallgrass prairie streams0 aEffects of experimental forest removal on macroinvertebrate prod0 v343 a

Encroachment by woody vegetation is a major threat to tallgrass prairie streams, and converts them from open- to closed-canopy systems. This change presumably shifts the relative importance of basal resources from autochthonous to allochthonous and may alter functional feeding group composition and production of consumers. Riparian trees were removed from 2 headwater stream reaches on the Konza Prairie Biological Station to examine effects of forest encroachment and removal. Removal reaches were compared to reaches with naturally open and closed canopies before and after manipulation. Benthic organic matter and macroinvertebrates were sampled monthly for 1 y before (year 1) and after (year 2) riparian forest removal. Total secondary production in removal reaches ranged from 8.9 to 10.2 g ash-free dry mass (AFDM) m−2 y−1 in year 1, and increased significantly to 13.4 to 14.5 g AFDM m−2 y−1 in year 2. Scraper production in removal reaches was 2.8 to 3.9 g AFDM m−2 y−1 in year 1, and increased significantly to 6.0 to 8.7 g AFDM m−2 y−1 in year 2. Shredders did not respond negatively to the removal, but scrapers dominated production (45-60% of total) in open and removal reaches after manipulation. Total production in naturally open reaches was 7.6 to 12.6 g AFDM m−2 y−1 in year 1 and decreased to 6.5 to 9.8 g AFDM m−2 y−1 in year 2. Riparian forest removal altered macroinvertebrate production and functional structure, but higher production in removal reaches than in open reaches after manipulation suggested that natural conditions were not restored 1 y after removal. However, ordinations indicated communities in open and removal reaches became more similar after manipulation. Forest encroachment alters prairie stream structure and function, and riparian forest removal may be an effective restoration and management practice for remaining prairie streams.

1 aVanderymyde, J.M.1 aWhiles, M.R. uhttps://www.journals.uchicago.edu/doi/10.1086/68044202956nas a2200313 4500008004100000245012400041210006900165300001400234490000700248520203700255100001802292700001702310700001802327700001702345700001502362700001802377700001602395700001402411700001702425700001702442700001502459700001902474700001902493700001902512700001402531700001802545700001702563856006202580 2015 eng d00aLong-term changes in structure and function of a tropical headwater stream following a disease-driven amphibian decline0 aLongterm changes in structure and function of a tropical headwat a575 - 5890 v603 a

1. Taxonomic and functional diversity in freshwater habitats is rapidly declining, but we know little about how such declines will ultimately affect ecosystems. Neotropical streams are currently experiencing massive losses of amphibians, with many losses linked to the chytrid fungus, Batrachochytrium dendrobatidis (Bd). 2. We examined the ecological consequences of the disease-driven loss of amphibians from a Panamanian stream. We quantified basal resources, macroinvertebrates, N uptake and fluxes through food-web components and ecosystem metabolism in 2012 and 2014 and compared them to pre-decline (2006) and 2 year post-decline (2008) values from a prior study. 3. Epilithon biomass accrued after the decline, more than doubling between 2006 and 2012, but then decreased fivefold from 2012 to 2014. In contrast, suspended particulate organic matter (SPOM) concentrations declined continuously after the amphibian decline through 2014. 4. Biomass of filter-feeding, grazing and shredding macroinvertebrates decreased from 2006 to 2014, while collector–gatherers increased during the same time period. Macroinvertebrate taxa richness decreased from 2006 (52 taxa) to 2012 (30 taxa), with a subsequent increase to 51 taxa in 2014. 5. Community respiration, which initially decreased after the amphibian decline, remained lower than pre-decline in 2012 but was greater than pre-decline values in 2014. Gross primary production remained low and similar among years, while inline image uptake length in both 2012 and 2014 was longer than pre-decline. Nitrogen flux to epilithon increased after the decline and continued to do so through 2014, but N fluxes to fine particulate organic matter and SPOM decreased and remained low. 6. Our findings underscore the importance of studying the ecological consequences of declining biodiversity in natural systems over relatively long time periods. There was no evidence of functional redundancy or compensation by other taxa after the loss of amphibians, even after 8 years.

1 aRantala, H.M.1 aNelson, A.M.1 aFulgoni, J.N.1 aWhiles, M.R.1 aHall, R.O.1 aDodds, W., K.1 aVerburg, P.1 aHuryn, A.1 aPringle, C..1 aKilham, S.S.1 aLips, K.R.1 aColon-Gaud, C.1 aRugenski, A.T.1 aPeterson, S.D.1 aFritz, K.1 aMcLeran, K.E.1 aConnelly, S. uhttps://onlinelibrary.wiley.com/doi/abs/10.1111/fwb.1250502359nas a2200181 4500008004100000245008800041210006900129300000900198490000700207520178200214100001801996700001702014700001802031700001602049700002102065700001802086856007302104 2015 eng d00aPatch-burn grazing effects on the ecological integrity of tallgrass prairie streams0 aPatchburn grazing effects on the ecological integrity of tallgra a11480 v443 a

Conversion to agriculture, habitat fragmentation, and the loss of native grazers have made tallgrass prairie one of the most endangered ecosystems. One management option for the remaining prairie parcels, patch-burn grazing (PBG), applies a controlled burn to a portion of the prairie to attract cattle, creating a mosaic of more- and less-grazed patches. Although beneficial to cattle and grassland birds, the potential impacts of PBG on streams have not been studied, and a holistic approach is needed to ensure against adverse effects. We used a Before-After-Control-Impact design to assess potential impacts of PBG with and without riparian protection on tallgrass prairie headwater streams. We sampled stream macroinvertebrates and benthic organic matter 2 yr before and 2 yr during PBG treatments on two grazed watersheds with riparian fencing (fenced), two unfenced grazed watersheds (unfenced), and two ungrazed (control) watersheds. Very fine benthic organic matter increased significantly (51%) in unfenced streams compared with controls ( < 0.007), and fine particulate organic matter (<1 mm and >250 µm) increased 3-fold in the unfenced streams compared with controls ( = 0.008). The contribution of fine inorganic sediments to total substrata increased 28% in unfenced streams during PBG, which was significantly different from controls ( = 0.03). Additionally, the abundance of Ephemeroptera, Plecoptera, and Trichoptera taxa decreased from 7635 to 687 individuals m in unfenced streams, which was significantly lower than in control streams ( = 0.008). Our results indicate that PBG adversely influences prairie streams through sediment inputs and reductions in sensitive invertebrate taxa, but riparian fencing can alleviate these impacts.

1 aJackson, K.E.1 aWhiles, M.R.1 aDodds, W., K.1 aReeve, J.D.1 aVandermyde, J.M.1 aRantala, H.M. uhttps://dl.sciencesocieties.org/publications/jeq/abstracts/44/4/114802375nas a2200241 4500008004100000245010700041210006900148300001000217490000700227520167000234653001701904653001001921653001001931653001601941653001701957653001101974100001801985700001702003700001702020700001802037700002102055856005702076 2015 eng d00aThe Stream Biome Gradient Concept: factors controlling lotic systems across broad biogeographic scales0 aStream Biome Gradient Concept factors controlling lotic systems  a1 -190 v343 a

We propose the Stream Biome Gradient Concept as a way to predict macroscale biological patterns in streams. This concept is based on the hypothesis that many abiotic and biotic features of streams change predictably along climate (temperature and precipitation) gradients because of direct influences of climate on hydrology, geomorphology, and interactions mediated by terrestrial vegetation. The Stream Biome Gradient Concept generates testable hypotheses related to continental variation among streams worldwide and allows aquatic scientists to understand how results from one biome might apply to a less-studied biome. Some predicted factors change monotonically across the biome/climate gradients, whereas others have maxima or minima in the central portion of the gradient. For example, predictions across the gradient from drier deserts through grasslands to wetter forests include more permanent flow, less bare ground, lower erosion and sediment transport rates, decreased importance of autochthonous C inputs to food webs, and greater stream animal species richness. In contrast, effects of large ungulate grazers on streams are expected to be greater in grasslands than in forests or deserts, and fire is expected to have weaker effects in grassland streams than in desert and forest streams along biome gradients with changing precipitation and constant latitude or elevation. Understanding historic patterns among biomes can help describe the evolutionary template at relevant biogeographic scales, can be used to broaden other conceptual models of stream ecology, and could lead to better management and conservation across the broadest scales.

10abiogeography10abiome10alotic10amacro-scale10amacrosystems10astream1 aDodds, W., K.1 aGido, K., B.1 aWhiles, M.R.1 aDaniels, M.D.1 aGrudzinski, B.P. uhttps://www.journals.uchicago.edu/doi/10.1086/67975602431nas a2200373 4500008004100000245012200041210006900163300001500232490000700247520133300254100001801587700002401605700001901629700001501648700001601663700001801679700001601697700001701713700001801730700001901748700001901767700001301786700001901799700001701818700002101835700001801856700001801874700002001892700001401912700002401926700001901950700001401969856007401983 2014 eng d00aYou are not always what we think you eat: selective assimilation across multiple whole-stream isotopic tracer studies0 aYou are not always what we think you eat selective assimilation  a2757 -27670 v953 a

Analyses of 21 15N stable isotope tracer experiments, designed to examine food web dynamics in streams around the world, indicated that the isotopic composition of food resources assimilated by primary consumers (mostly invertebrates) poorly reflected the presumed food sources. Modeling indicated that consumers assimilated only 33–50% of the N available in sampled food sources such as decomposing leaves, epilithon, and fine particulate detritus over feeding periods of weeks or more. Thus, common methods of sampling food sources consumed by animals in streams do not sufficiently reflect the pool of N they assimilate. Isotope tracer studies, combined with modeling and food separation techniques, can improve estimation of N pools in food sources that are assimilated by consumers. Food web studies that use putative food samples composed of actively cycling (more readily assimilable) and refractory (less assimilable) N fractions may draw erroneous conclusions about diets, N turnover, and trophic linkages of consumers. By extension, food web studies using stoichiometric or natural abundance approaches that rely on an accurate description of food-source composition could result in errors when an actively cycling pool that is only a fraction of the N pool in sampled food resources is not accounted for.

1 aDodds, W., K.1 aCollins, Scott., L.1 aHamilton, S.K.1 aTank, J.L.1 aJohnson, S.1 aWebster, J.R.1 aSimon, K.S.1 aWhiles, M.R.1 aRantala, H.M.1 aMcDowell, W.H.1 aPeterson, S.D.1 aRiis, T.1 aCrenshaw, C.L.1 aThomas, S.A.1 aKristensen, P.B.1 aCheever, B.M.1 aFlecker, A.S.1 aGriffiths, N.A.1 aCrowl, T.1 aRosi-Marshall, E.J.1 aEl-Sabaawi, R.1 aMarti, E. uhttps://esajournals.onlinelibrary.wiley.com/doi/abs/10.1890/13-2276.102265nas a2200169 4500008004100000245007800041210006900119300001300188490000700201520172700208100001701935700001801952700001801970700001701988700001802005856007202023 2013 eng d00aEcosystem characteristics of remnant, headwater tallgrass prairie streams0 aEcosystem characteristics of remnant headwater tallgrass prairie a239 -2490 v423 a

North America has lost >95% of its native tallgrass prairie due to land conversion, making prairie streams one of the most endangered ecosystems. Research on the basic ecosystem characteristics of the remaining natural prairie streams will inform conservation and management. We examined the structure and function of headwater streams draining tallgrass prairie tracts at Osage Prairie in Missouri and the Konza Prairie Biological Station in Kansas and compared those values with literature values for streams draining agricultural watersheds in the region. We quantified physicochemical and biological characteristics for 2 yr. Streams at Osage and Konza were characterized by low nutrients and low suspended sediments (substantially lower than impacted sites in the region), slight heterotrophic status, and high temporal variability. Suspended sediments and nutrient concentrations were generally low in all prairie streams, but storms increased concentrations of both by 3- to 12-fold. Spring prescribed burns were followed by a slight increase in chlorophyll a and decreased nutrients, potentially due to greater light availability. Benthic macroinvertebrate communities at Osage showed seasonal patterns that were probably linked to variable hydrology. We found nine amphibian species using the Osage streams as habitat or breeding sites, but little usage at Konza was probably due to dry conditions and low discharge. Our study indicates that two remnant tallgrass prairie streams along a longitudinal gradient are fairly similar in terms of physicochemical features and have good water quality relative to agricultural watersheds but can differ considerably in macroinvertebrate and amphibian abundance.

1 aLarson, D.M.1 aDodds, W., K.1 aJackson, K.E.1 aWhiles, M.R.1 aWinders, K.R. uhttps://dl.sciencesocieties.org/publications/jeq/abstracts/42/1/23902311nas a2200217 4500008004100000245016300041210006900204300001300273490000800286520157200294653001601866653001001882653001701892653002801909653001901937100001901956700001701975700001701992700001802009856006602027 2013 eng d00aInfluence of macroconsumers, stream position, and nutrient gradients on invertebrate assemblage development following flooding in intermittent prairie streams0 aInfluence of macroconsumers stream position and nutrient gradien a169 -1820 v7143 a

Climate change in the US Great Plains is expected to result in less frequent but more severe floods. This will affect hydrologic cycles, stream organisms, and ultimately ecosystem structure and function. We examined factors influencing invertebrate assemblages following flooding in 3 reaches (20 pools) of Kings Creek, an intermittent prairie stream on the Konza Prairie Biological Station, using replicated macroconsumer enclosures (fishless, dace, shiners, ambient). Invertebrate densities and biomass increased rapidly following scouring, including rapid colonizing taxa and relatively long-lived taxa, but macroconsumers had no significant effects. Rather, distance, which was negatively correlated with the concentration of dissolved inorganic nitrogen, from the downstream confluence with a larger stream significantly influenced assemblage structure, with higher richness and greater nutrient concentrations closer to the confluence. Results support previous findings that recovery patterns following flooding in this grassland stream are strongly influenced by proximity to refuges. Furthermore, physical rather than biological factors appear more influential in structuring invertebrate assemblages in these frequently disturbed systems. Predicted increases in the intensity and duration of hydrologic disturbances will increase direct impacts on stream communities, relative to indirect effects through potential changes in macroconsumer communities. Human activities that alter refuges may further impede recovery following hydrologic disturbances.

10adisturbance10aFlood10aInvertebrate10aMacroconsumer Gradients10aPrairie stream1 aBertrand, K.N.1 aWhiles, M.R.1 aGido, K., B.1 aMurdock, J.N. uhttps://link.springer.com/article/10.1007%2Fs10750-013-1534-502614nas a2200133 4500008004100000245012800041210006900169260004900238490001400287520209900301100001802400700001702418856004502435 2013 eng d00aInfluences of patch-burn grazing and riparian protection on the ecological integrity of tallgrass prairie headwater streams0 aInfluences of patchburn grazing and riparian protection on the e aCarbondale, ILbSouthern Illinois University0 vMS Thesis3 a

Conversion to agriculture, land fragmentation, and removal of native grazers have made tallgrass prairies and the streams that drain them one of the most imperiled systems on earth. Patch-burn grazing (PBG), an increasingly common management practice on remaining prairie parcels, has been shown to benefit cattle and grassland birds. However, potential influences of this practice on streams are unknown. To address this, we sampled stream macroinvertebrates and benthic organic matter two years before and three years during PBG on two watersheds with riparian fencing (fenced), two grazed watersheds without riparian fencing (unfenced), and two ungrazed (control) watersheds. Very fine benthic organic matter increased 51% in unfenced watersheds after implementation of PBG, accompanied by a threefold increase in fine organic sediments in the same watersheds. Contribution of fine inorganic sediments to total substrata increased 28% in unfenced watersheds during PBG, while fine inorganic sediments decreased in both the control (18%) and fenced (16%) watersheds. Increases in the contribution of Chironomidae to total macroinvertebrate abundance (18% before, 49% during PBG) and biomass (10% before, 19% during PBG) were evident in unfenced streams. In contrast, abundance of sensitive EPT taxa decreased an order of magnitude from 7,635 to 687 individuals m-2 in unfenced streams, but did not change in fenced and control streams. Increases in tolerant taxa and fine organic and inorganic sediments, along with reductions in metrics of biotic integrity, suggest PBG adversely impacts prairie streams. However, the absence of negative responses in fenced watersheds indicates that riparian fencing can mitigate these impacts by serving as a buffer to prevent excess sedimentation. In order to properly manage remaining tallgrass prairie parcels, it is important to consider both the aquatic and terrestrial components of these systems, as they are tightly linked. Results from this study provide a basis for management and policy decisions regarding remaining grassland watersheds.

1 aJackson, K.E.1 aWhiles, M.R. uhttp://opensiuc.lib.siu.edu/theses/1345/03159nas a2200133 4500008004100000245010400041210006900145260004900214490001400263520266500277100002102942700001702963856004502980 2013 eng d00aMacroinvertebrate responses to removal of riparian woody vegetation along tallgrass prairie streams0 aMacroinvertebrate responses to removal of riparian woody vegetat aCarbondale, ILbSouthern Illinois University0 vMS Thesis3 a

Woody vegetation encroachment has become a major threat to tallgrass prairie streams mainly because of fire suppression. This process converts prairie streams from open to closed canopy systems. The effects of these riparian changes are poorly understood, but the relative importance of basal resources presumably shifts from primarily autochthonous to allochthonous with increasing canopy cover, potentially altering macroinvertebrate functional structure and production. To assess the effects of woody vegetation encroachment on stream ecosystem structure and function, riparian trees were removed from two headwater stream reaches on the Konza Prairie Biological Station (KPBS) in eastern Kansas. Experimental stream reaches were compared to streams with naturally open and closed canopies before and after the manipulation. Benthic organic matter and macroinvertebrates were collected monthly from each reach for one year before and one year after woody vegetation removal. Total community production in canopy removal reaches ranged from 8.9-10.2 g AFDM m-2 y-1 before riparian removal, and this increased significantly to 13.4-14.5 g AFDM m-2 y-1 after riparian removal. Scraper production in canopy removal reaches was 2.8-3.9 g AFDM m-2 y-1 before riparian removal, and increased significantly to 6.0-8.7 g AFDM m-2 y-1 after riparian removal, presumably due to enhanced food availability. Total community production in naturally open reaches ranged from 7.6-12.6 g AFDM m-2 y-1 before riparian removal and decreased to 6.5-9.8 g AFDM m-2 y-1 after riparian removal. Riparian forest removal altered macroinvertebrate production and functional structure, but higher macroinvertebrate production in canopy removal reaches compared to naturally open reaches suggested natural conditions were not restored one year after riparian removal. However, macroinvertebrate communities in naturally open and canopy removal reaches became more similar after riparian removal. Functional structure, based on production, in naturally open and canopy removal reaches after riparian removal was dominated by scrapers (45-60% of total production), with similar proportions of collector-gatherers (12-26%) and predators (15-25%). Collector-filterers and shredders contributed < 9% of total production in naturally open and canopy removal reaches after riparian removal. Results demonstrate that woody vegetation encroachment and riparian forest removal significantly influence tallgrass prairie stream structure and function. Information from this study can help inform and guide management, restoration, and conservation of remaining tallgrass prairie streams.

1 aVandermyde, J.M.1 aWhiles, M.R. uhttp://opensiuc.lib.siu.edu/theses/1068/00499nas a2200145 4500008004100000245009400041210006900135300001300204490000700217100001800224700001800242700001700260700001700277856005900294 2011 eng d00aDynamic influences of nutrients and grazing fish on periphyton during recovery from flood0 aDynamic influences of nutrients and grazing fish on periphyton d a331 -3450 v301 aMurdock, J.N.1 aDodds, W., K.1 aGido, K., B.1 aWhiles, M.R. uhttps://www.journals.uchicago.edu/doi/10.1899/10-039.102089nas a2200145 4500008004100000245012400041210006900165300001300234490000700247520155900254100001801813700001701831700001601848856007901864 2011 eng d00aPatterns of macroinvertebrate production, trophic structure, and energy flow along a tallgrass prairie stream continuum0 aPatterns of macroinvertebrate production trophic structure and e a887 -8980 v563 a

We estimated benthic organic matter standing stocks, macroinvertebrate production, food-web structure, and stream metabolism along a longitudinal continuum of Kings Creek at Konza Prairie Biological Station in Kansas. Benthic macroinvertebrates were sampled for 1 yr from three stream reaches (grass, shrub, gallery forest). Total habitat-weighted production ranged from 9.1 g to 31.9 g ash-free dry weight m−2 yr−1 with the grass headwaters accounting for the highest production. Functional group contributions to production were similar along the continuum, with collector–gatherers (40–56% of total) and predators (23–38%) dominating all reaches. Detrital pathways appeared to account for most energy flow in all reaches, and all reaches were net heterotrophic on all dates when metabolism was measured, except for the grass headwater reach in spring. Predators were well-represented and consumed 65–107% of total macroinvertebrate production, whereas scrapers (11–15%), shredders (2–4%), and filterers (< 1%) consumed relatively small percentages of available resources. Dominance of predators suggested top-down controls are important in this system. However, changes in energy flow through other groups reflected longitudinal variation in resource availability. This prairie stream continuum conforms to some predictions of conceptual stream continua models, but biotic interactions, which are often not considered, may override some predicted responses to changes in the physical template.

1 aWhiting, D.P.1 aWhiles, M.R.1 aStone, M.L. uhttps://aslopubs.onlinelibrary.wiley.com/doi/abs/10.4319/lo.2011.56.3.088702350nas a2200169 4500008004100000245011900041210006900160300001500229490000700244520176600251100001802017700001702035700001802052700001902070700001702089856007402106 2010 eng d00aConsumer return chronology alters recovery trajectory of stream ecosystem structure and function following drought0 aConsumer return chronology alters recovery trajectory of stream  a1048 -10620 v913 a

Consumers are increasingly being recognized as important drivers of ecological succession, yet it is still hard to predict the nature and direction of consumer effects in nonequilibrium environments. We used stream consumer exclosures and large outdoor mesocosms to study the impact of macroconsumers (i.e., fish and crayfish) on recovery of intermittent prairie streams after drying. In the stream, macroconsumers altered system recovery trajectory by decreasing algal and macroinvertebrate biomass, primary productivity, and benthic nutrient uptake rates. However, macroconsumer influence was transient, and differences between exclosures and controls disappeared after 35 days. Introducing and removing macroconsumers after 28 days resulted mainly in changes to macroinvertebrates. In mesocosms, a dominant consumer (the grazing minnow Phoxinus erythrogaster) reduced macroinvertebrate biomass but had little effect on algal assemblage structure and ecosystem rates during recovery. The weak effect of P. erythrogaster in mesocosms, in contrast to the strong consumer effect in the natural stream, suggests that both timing and diversity of returning consumers are important to their overall influence on stream recovery patterns. Although we found that consumers significantly altered ecosystem structure and function in a system experiencing rapid changes in abiotic and biotic factors following disturbance, consumer effects diminished over time and trajectories converged to similar states with respect to primary producers, in spite of differences in consumer colonization history. Thus, consumer impacts can be substantial in recovering ecosystems and are likely to be dependent on the disturbance regime and diversity of the consumer community.

1 aMurdock, J.M.1 aGido, K., B.1 aDodds, W., K.1 aBertrand, K.N.1 aWhiles, M.R. uhttps://esajournals.onlinelibrary.wiley.com/doi/abs/10.1890/08-2168.103055nas a2200157 4500008004100000245013200041210006900173300001300242520245800255100001702713700001902730700001802749700001802767700001702785856009502802 2010 eng d00aDisturbance mediated effects of stream fishes on ecosystem processes: concepts and results from highly variable prairie streams0 aDisturbance mediated effects of stream fishes on ecosystem proce a593 -6173 a

Stream fishes can have strong top-down and bottom-up effects on ecosystem processes. However, the dynamic nature of streams constrains our ability to generalize these effects across systems with different disturbance regimes and species composition. To evaluate the role of fishes following disturbance, we used a series of field and mesocosm experiments that quantified the influence of grazers and water column minnows on primary productivity, periphyton structure, organic matter pools, and invertebrate communities following either scouring floods or drying of prairie streams. Results from individual experiments revealed highly significant effects of fishes, but the direction or magnitude of effects varied among experiments. Meta-analyses across experiments indicated that grazers consistently reduced the relative amount of fine benthic organic matter (FBOM) and chironomid abundance within 2 weeks after disturbances. However, effect sizes (log response ratios) were heterogeneous across experiments for algal biomass and algal filament lengths measured more than 4 weeks after a disturbance and potentially associated with system productivity and grazer densities. A similar analysis of 3–4 experiments using water column minnows only found a consistent trend of decreasing FBOM in fish treatments relative to controls when measured less than 2 weeks after disturbances and increase in gross primary productivity measured more than 4 weeks after disturbance. These results, along with those of others, were used to develop a conceptual framework for predicting the potential role of fishes in streams following disturbances (flood and drying). Both theoretical and empirical research shows that recovery of stream ecosystem processes will depend on the resilience of autotrophic and heterotrophic communities following disturbance. Fish effects may vary among functional groups but are generally predicted to be greatest during early stages of succession when algal and invertebrate communities are less complex and their biomass is low relative to fish biomass. Our analysis underscores the context dependency of consumer effects on ecosystem structure and function in nonequilibrium conditions and suggests that factors regulating fish densities and colonization of algal and invertebrate taxa need to be evaluated to predict the consequences of biodiversity loss in streams with variable or human-modified disturbance regimes.

1 aGido, K., B.1 aBertrand, K.N.1 aMurdock, J.N.1 aDodds, W., K.1 aWhiles, M.R. uhttps://www.k-state.edu/fishecology/msreprints/Gido%20et%20al.2010%20AFSbook%20chapter.pdf02579nas a2200133 4500008004100000245011200041210006900153260004900222490001400271520208100285100001802366700001702384856004402401 2010 eng d00aMacroinvertebrate production, trophic structure, and energy flow along a tallgrass prairie stream continuum0 aMacroinvertebrate production trophic structure and energy flow a aCarbondale, ILbSouthern Illinois University0 vMS Thesis3 a

Conceptual models of stream continua predict that energy flow and consumer functional structure change predictably with the physical attributes of a stream. To quantify these relationships in a prairie landscape, I estimated macroinvertebrate production, benthic organic matter standing stocks, and resource consumption and egestion by consumer groups along a longitudinal continuum of Kings Creek, a tallgrass prairie stream draining the Konza Prairie Biological Station in Eastern Kansas. I sampled benthic macroinvertebrates for 1 year from three stream reaches, each bordered by distinct riparian vegetation. Riparian vegetation along the continuum ranged from grassy headwaters to shrubby mid-reaches to lower reaches bordered by gallery forest. Total habitat-weighted production ranged from 31.9 g ash-free dry mass (AFDM) m-2 y-1 in the grassy headwater reach to 9.1 g AFDM m-2 y-1 in the shrubby reach to 17.0 g AFDM m-2 y-1 in the gallery forest. Functional group contributions to production generally were similar along the continuum, with collector-gatherers (40%-56% of total) and Predators (23%-38%) dominating all reaches. Quantitative food webs indicated detrital pathways dominated energy flow in all reaches, with collector-gatherers accounting for most energy flow through primary consumers. Predators were well represented and consumed 75% - 135% of total macroinvertebrate production whereas shredders (2-4%), scrapers (11-15%), and filterers (<1%) consumed a small percentage of their particular resources. High production and consumption estimates for macroinvertebrate predators suggest top-down controls are important in this system. Although functional structure was fairly similar among reaches, changes in energy flow through some groups reflected longitudinal changes in resource availability. Results indicate that this tallgrass prairie stream ecosystem is intermediate in the context of predictions of conceptual stream continua models, and biotic interactions may override some predicted responses to changes in the physical template.

1 aWhiting, D.P.1 aWhiles, M.R. uhttp://opensiuc.lib.siu.edu/theses/120/02518nas a2200169 4500008004100000245009700041210006900138300001300207490000800220520195400228100001902182700001702201700001802218700001802236700001702254856007702271 2009 eng d00aDisturbance frequency and functional identity mediate ecosystem processes in prairie streams0 aDisturbance frequency and functional identity mediate ecosystem  a917 -9330 v1183 a

A major consequence of climate change will be the alteration of precipitation patterns and concomitant changes in the flood frequencies in streams. Species losses or introductions will accompany these changes, which necessitates understanding the interactions between altered disturbance regimes and consumer functional identity to predict dynamics of streams. We used experimental mesocosms and field enclosures to test the interactive effects of flood frequency and two fishes from distinct consumer groups (benthic grazers and water-column minnows) on recovery of stream ecosystem properties (algal form and biomass, invertebrate densities, metabolism and nutrient uptake rates). Our results generally suggest that periphyton communities under nutrient limitation are likely to recover more quickly when grazing and water-column minnows are present and these effects can diminish or reverse with time since the disturbance. We hypothesized that increased periphyton production and biomass was the result of increased nutrient turnover, but decreased light limitation and indirect effects on other trophic levels are alternative explanations. Recovery of stream ecosystem properties after a natural flood differed from mesocosms (e.g. lower algal biomass and no long algal filaments present) and species manipulations did not explain recovery of ecosystem properties; rather, ecosystem processes varied along a downstream gradient of increasing temperature and nutrient concentrations. Different results between field enclosures and experimental mesocosms are attributable to a number of factors including differences in algal and invertebrate communities in the natural stream and relatively short enclosure lengths (mean area=35.8 m2) compared with recirculating water in the experimental mesocosms. These differences may provide insight into conditions necessary to elicit a strong interaction between consumers and ecosystem properties.

1 aBertrand, K.N.1 aGido, K., B.1 aDodds, W., K.1 aMurdock, J.N.1 aWhiles, M.R. uhttps://onlinelibrary.wiley.com/doi/abs/10.1111/j.1600-0706.2008.16849.x01706nas a2200193 4500008004100000245011900041210006900160300001300229490000700242520107100249653001901320653002101339653001601360653001801376653001501394100002001409700001701429856006601446 2008 eng d00aLife history and production of the riffle beetle, Stenelmis crenata (Say) (Elmidae), in a tallgrass prairie stream0 aLife history and production of the riffle beetle Stenelmis crena a197 -2040 v303 a

We examined life history dynamics and estimated production of the riffle beetle, Stenelmis crenata (Say, 1824), in a tallgrass prairie stream. Stenelmis crenata had a univoltine life cycle with larvae present year-round. Recruitment of first instars occurred from June–October, larval growth was synchronised through the winter, pupation occurred in late spring, and adults first appeared in late May. Adults were most abundant (24 individuals/m2) during summer and were present in samples through October. For larval biomass and production estimates, a body length–mass relationship (ash-free dry mass [AFDM] = 0.0079*TL2.7595) was constructed. Mean annual density and biomass of larvae were 235 individuals/m2 and 90.7 mg AFDM/m2, respectively. Annual larval production was 493 mg/m2/y, representing a total of ∼101 g AFDM for the stream reach examined. Production estimates for S. crenata in this stream were high compared to other estimates for elmids, and this species comprised an appreciable portion of total scraper (13.5%) production.

10aaquatic insect10agrassland stream10aGrowth rate10aKonza Prairie10alife cycle1 aStagliano, D.M.1 aWhiles, M.R. uhttps://www.tandfonline.com/doi/abs/10.1080/0165042080233114101994nas a2200265 4500008004100000245007900041210006900120300001300189490000700202520119800209100001601407700001901423700001601442700001701458700001901475700001401494700001501508700001701523700001501540700001701555700001401572700001601586700001701602856010901619 2007 eng d00aDoes species diversity limitproductivity in natural grassland communities?0 aDoes species diversity limitproductivity in natural grassland co a680 -6890 v103 aTheoretical analyses and experimental studies of synthesized assemblages indicate that under particular circumstances species diversity can enhance community productivity through niche complementarity. It remains unclear whether this process has important effects in mature natural ecosystems where competitive feedbacks and complex environmental influences affect diversity–productivity relationships. In this study, we evaluated diversity–productivity relationships while statistically controlling for environmental influences in 12 natural grassland ecosystems. Because diversity–productivity relationships are conspicuously nonlinear, we developed a nonlinear structural equation modeling (SEM) methodology to separate the effects of diversity on productivity from the effects of productivity on diversity. Meta-analysis was used to summarize the SEM findings across studies. While competitive effects were readily detected, enhancement of production by diversity was not. These results suggest that the influence of small-scale diversity on productivity in mature natural systems is a weak force, both in absolute terms and relative to the effects of other controls on productivity.1 aGrace, J.B.1 aAnderson, T.M.1 aSmith, M.D.1 aSeabloom, E.1 aAndelman, S.J.1 aMeche, G.1 aWeiher, E.1 aAllain, L.K.1 aJutila, H.1 aSankaran, M.1 aKnops, J.1 aRitchie, M.1 aWhiles, M.R. uhttp://lter.konza.ksu.edu/content/does-species-diversity-limitproductivity-natural-grassland-communities02245nas a2200253 4500008004100000245007600041210006900117300001300186490000800199520145100207653001901658653001901677653001701696653002301713653001801736100001801754700001701772700001701789700002401806700001601830700001801846700001701864856011001881 2007 eng d00aStream insect occupancy-frequency patterns and metapopulation structure0 aStream insect occupancyfrequency patterns and metapopulation str a313 -3210 v1513 aAn understanding of the distribution patterns of organisms and the underlying factors is a fundamental goal of ecology. One commonly applied approach to visualize these is the analysis of occupancy-frequency patterns. We used data sets describing stream insect distributions from different regions of North America to analyze occupancy-frequency patterns and assess the effects of spatial scale, sampling intensity, and taxonomic resolution on these patterns. Distributions were dominated by satellite taxa (those occurring in ≤10% of sites), whereas the occurrence of core taxa (occurring in ≥90% of sites) determined the overall modality of occupancy-frequency patterns. The proportions of satellite taxa increased with spatial scale and showed positive relationships with sampling intensity (r 2=0.74–0.96). Furthermore, analyses of data sets from New York (USA) showed that generic-level assessments underestimated the satellite class and occasionally shifted occupancy-frequency distributions from unimodal to bimodal. Our results indicate that, regardless of species- or generic-level taxonomy, stream insect communities are characterized by satellite species and that the proportion of satellite species increases with spatial scale and sampling intensity. Thus, niche-based models of occupancy-frequency patterns better characterize stream insect communities than metapopulation models such as the core-satellite species hypothesis.10aaquatic insect10aCore-satellite10aDistribution10aSampling intensity10aspatial scale1 aHeatherly, T.1 aWhiles, M.R.1 aGibson, D.J.1 aCollins, Scott., L.1 aHuryn, A.D.1 aJackson, J.K.1 aPalmer, M.A. uhttp://lter.konza.ksu.edu/content/stream-insect-occupancy-frequency-patterns-and-metapopulation-structure01563nas a2200133 4500008004100000245006400041210006000105300001300165490000700178520111700185100001701302700001901319856009101338 2006 eng d00aThe ecological significance of tallgrass prairie arthropods0 aecological significance of tallgrass prairie arthropods a387 -4120 v513 aTallgrass prairie (TGP) arthropods are diverse and abundant, yet they remain poorly documented and there is still much to be learned regarding their ecological roles. Fire and grazing interact in complex ways in TGP, resulting in a shifting mosaic of resource quantity and quality for primary consumers. Accordingly, the impacts of arthropod herbivores and detritivores are expected to vary spatially and temporally. Herbivores generally do not control primary production. Rather, groups such as grasshoppers have subtle effects on plant communities, and their most significant impacts are often on forbs, which represent the bulk of plant diversity in TGP. Belowground herbivores and detritivores influence root dynamics and rhizosphere nutrient cycling, and above- and belowground groups interact through plant responses and detrital pathways. Large-bodied taxa, such as cicadas, can also redistribute significant quantities of materials during adult emergences. Predatory arthropods are the least studied in terms of ecological significance, but there is evidence that top-down processes are important in TGP.1 aWhiles, M.R.1 aCharlton, R.E. uhttp://lter.konza.ksu.edu/content/ecological-significance-tallgrass-prairie-arthropods01527nas a2200169 4500008004100000245006600041210006500107300001300172490000700185520099300192100001801185700001701203700001701220700001601237700001901253856008501272 2004 eng d00aLife on the edge: the ecology of Great Plains prairie streams0 aLife on the edge the ecology of Great Plains prairie streams a207 -2810 v543 aGreat Plains streams are highly endangered and can serve as model systems for studying disturbance ecology and related issues of resistance and resilience in temperate freshwaters. These streams exist in a precarious balance between flood and drying. In general, microbial activity recovers in days to weeks after drying or flooding, and invertebrate and fish species are quick to follow. In lower forested reaches, floods may be more intense but drying less common. Upstream reaches of prairie streams are characterized by frequent drying, little canopy cover, and limited leaf input. Life history and adaptations alter the ways in which stream organisms respond to these linear patterns. Human modification has altered these patterns, leading to large-scale loss of native grassland streams. The future for Great Plains streams is bleak, given the land-use changes and water-use patterns in the region and the large areas required to preserve intact, ecologically functional watersheds.1 aDodds, W., K.1 aGido, K., B.1 aWhiles, M.R.1 aFritz, K.M.1 aMatthews, W.J. uhttp://lter.konza.ksu.edu/content/life-edge-ecology-great-plains-prairie-streams02312nas a2200253 4500008004100000245010500041210006900146300001300215490000700228520150300235653001501738653001301753653001401766653001101780653002301791653001401814653001801828100001801846700001701864700001701881700001601898700001901914856012501933 2004 eng d00aQuality and quantity of suspended particles in rivers: Continent-scale patterns in the United States0 aQuality and quantity of suspended particles in rivers Continents a355 -3670 v333 aSuspended solids or sediments can be pollutants in rivers, but they are also an important component of lotic food webs. Suspended sediment data for rivers were obtained from a United States–wide water quality database for 622 stations. Data for particulate nitrogen, suspended carbon, discharge, watershed area, land use, and population were also used. Stations were classified by United States Environmental Protection Agency ecoregions to assess relationships between terrestrial habitats and the quality and quantity of total suspended solids (TSS). Results indicate that nephelometric determinations of mean turbidity can be used to estimate mean suspended sediment values to within an order of magnitude (r2 = 0.89). Water quality is often considered impaired above 80 mg TSS L−1, and 35% of the stations examined during this study had mean values exceeding this level. Forested systems had substantially lower TSS and somewhat higher carbon-to-nitrogen ratios of suspended materials. The correlation between TSS and discharge was moderately well described by an exponential relationship, with the power of the exponent indicating potential acute sediment events in rivers. Mean sediment values and power of the exponent varied significantly with ecoregion, but TSS values were also influenced by land use practices and geomorphological characteristics. Results confirm that, based on current water quality standards, excessive suspended solids impair numerous rivers in the United States.10aEcoregions10aLand use10apollution10aSeston10aSuspended sediment10aTurbidity10awater quality1 aDodds, W., K.1 aGido, K., B.1 aWhiles, M.R.1 aFritz, K.M.1 aMatthews, W.J. uhttp://lter.konza.ksu.edu/content/quality-and-quantity-suspended-particles-rivers-continent-scale-patterns-united-states02698nas a2200157 4500008004100000245012600041210006900167300001500236490000700251520208300258100002002341700001902361700001602380700001702396856012702413 2004 eng d00aScale dependence in the relationship between species richness and productivity: the role of spatial and temporal turnover0 aScale dependence in the relationship between species richness an a2701 -27080 v853 aRecent research in aquatic systems suggests that productivity–richness relationships change with spatial scale and that species turnover (i.e., spatial and temporal variation in species composition) plays an important role in generating this scale dependence. The generality of such scale dependence and the effects of variation in temporal scale remain unknown. We examined the extent to which the richness–productivity relationship in terrestrial plant communities depends on spatial or temporal scale and evaluated how spatial and temporal turnover (i.e., species turnover in space and time) generates scale dependence in these relationships using data from two Long-Term Ecological Research (LTER) sites (Jornada and Konza). We found a weak hump-shaped relationship (Jornada) and no relationship (Konza) between richness and productivity at the smallest focal scale (1 m2 at Jornada and 50 m2 at Konza) at each site, but strong hump-shaped relationships at the largest focal scale (49 m2 at Jornada and 200 m2 at Konza) for each site. Relationships between spatial turnover and productivity at each site mirrored the productivity–richness relationships that emerged at the larger spatial scale (i.e., a significant hump-shaped pattern). In contrast, temporal turnover was unrelated to productivity, and hence increasing temporal scale did not appreciably change the form of the productivity–richness relationship. Our study suggests that the way in which productivity–richness relationships change with spatial or temporal scale depends on the form and strength of the underlying relationship between species turnover and productivity. Moreover, we contend that a dominant effect of increasing productivity is the generation of dissimilarity in species composition among localities that comprise a region, rather than increasing the number of species that occur within local communities. Thus, understanding the mechanisms that cause species turnover to vary with productivity is critical to understanding scale dependence in richness–productivity relationships.1 aChalcraft, D.R.1 aWilliams, J.W.1 aSmith, M.D.1 aWhiles, M.R. uhttp://lter.konza.ksu.edu/content/scale-dependence-relationship-between-species-richness-and-productivity-role-spatial-and02437nas a2200217 4500008004100000245015100041210006900192300001300261490000700274520165000281653002501931653001601956653001701972653001301989653001502002653002502017100002002042700001802062700001702080856012202097 2003 eng d00aEcosystem significance of crayfishes and central stonerollers in a tallgrass prairie stream: Functional differences between co-occurring omnivores0 aEcosystem significance of crayfishes and central stonerollers in a423 -4410 v223 aThe ecosystem significance of crayfishes (Orconectes nais (Faxon) and O. neglectus (Faxon)) and central stoneroller minnows (Campostoma anomalum (Rafinesque)), was examined in a tallgrass prairie stream by estimating the trophic basis of production and consumption for each species. Annual ash-free dry mass production and production to biomass ratios of C. anomalum (260 mg m−2 y−1, 1.3) were lower than that of O. nais (719 mg m−2 y−1, 2.4) and O. neglectus (508 mg m−2 y−1, 2.1). Gut content analysis revealed no significant differences in the percentages of the various food items ingested by O. nais and O. neglectus, indicating they were functionally similar with respect to the types of organic matter processed in this system. We found a significant difference among seasons in the % of invertebrates in C. anomalum guts (p = 0.0001) and the % of algae in Orconectes spp. guts (p = 0.005), indicating the importance of measuring resource use throughout the growing season. Leaves contributed most to Orconectes spp. annual production (45%) followed by animal matter (30%), algae (19%), and amorphous detritus (6%). Algae contributed most to C. anomalum production (47%) followed by amorphous detritus (30%), animal matter (21%), and leaves (2%). Orconectes spp. consumed more leaf litter, filamentous green algae, and macroinvertebrates than C. anomalum, whereas C. anomalum consumed more diatoms. Crayfish and central stonerollers are both omnivores that function as important consumers and processors of algae and detritus in this tallgrass prairie stream, but each focuses on slightly different types of similar resources.10acentral stonerollers10aGrowth rate10agut contents10aomnivory10aOrconectes10asecondary production1 aEvans-White, M.1 aDodds, W., K.1 aWhiles, M.R. uhttp://lter.konza.ksu.edu/content/ecosystem-significance-crayfishes-and-central-stonerollers-tallgrass-prairie-stream02817nas a2200337 4500008004100000245014100041210006900182300001500251490000700266520177500273653001202048653001402060653001802074653001602092653001502108653001502123653001802138653001502156653000902171653001402180653002202194653001302216653001502229653001702244100001902261700002002280700001502300700001802315700001702333856012902350 2003 eng d00aEffects of fire, mowing and fertilization effects on density and biomass of macroinvertebrates in North American tallgrass prairie soils0 aEffects of fire mowing and fertilization effects on density and  a1079 -10930 v353 aThe responses of tallgrass prairie plant communities and ecosystem processes to fire and grazing are well characterized. However, responses of invertebrate consumer groups, and particularly soil-dwelling organisms, to these disturbances are not well known. At Konza Prairie Biological Station, we sampled soil macroinvertebrates in 1994 and 1999 as part of a long-term experiment designed to examine the effects and interactions of annual fire, mowing, and fertilization (N and P) on prairie soil communities and processes. For nearly all taxa, in both years, responses were characterized by significant treatment interactions, but some general patterns were evident. Introduced European earthworms (Aporrectodea spp. and Octolasion spp.) were most abundant in plots where fire was excluded, and the proportion of the total earthworm community consisting of introduced earthworms was greater in unburned, unmowed, and fertilized plots. Nymphs of two Cicada genera were collected (Cicadetta spp. and Tibicen spp.). Cicadetta nymphs were more abundant in burned plots, but mowing reduced their abundance. Tibicen nymphs were collected almost exclusively from unburned plots. Treatment effects on herbivorous beetle larvae (Scarabaeidae, Elateridae, and Curculionidae) were variable, but nutrient additions (N or P) usually resulted in greater densities, whereas mowing usually resulted in lower densities. Our results suggest that departures from historical disturbance regimes (i.e. frequent fire and grazing) may render soils more susceptible to increased numbers of European earthworms, and that interactions between fire, aboveground biomass removal, and vegetation responses affect the structure and composition of invertebrate communities in tallgrass prairie soils.10abiomass10aCicadidae10aCurculionidae10adisturbance10aearthworms10aElateridae10aFertilization10aFertilizer10afire10agrassland10ainsect herbivores10anitrogen10aPhosphorus10aScarabaeidae1 aCallaham, M.A.1 aBlair, John, M.1 aTodd, T.C.1 aKitchen, D.J.1 aWhiles, M.R. uhttp://lter.konza.ksu.edu/content/effects-fire-mowing-and-fertilization-effects-density-and-biomass-macroinvertebrates-north02599nas a2200193 4500008004100000245010000041210006900141300001500210490000700225520191900232653002602151653001502177653002202192653001502214100001402229700001702243700001902260856012602279 2002 eng d00aAboveground invertebrate responses to land management differences in a central Kansas grassland0 aAboveground invertebrate responses to land management difference a1142 -11520 v313 aMacroinvertebrate communities in a central Kansas grassland were examined to assess their responses to differences in land management and explore their viability for biological assessment of grasslands. Canopy (drop-trap) and ground-dwelling (pitfall traps) communities were quantitatively sampled from June-September 1998 and 1999. The responses of the whole arthropod community and two focal groups, Coleopteran families and Orthopteran species, to three land use types (brome fields, old fields, and native prairies) were examined. Vegetation analyses reflected clear differences among land use types. Bromus inermis Leyss, an exotic grass, and Andropogon gerardii Vitman, a native grass, dominated brome fields and native prairie sites, respectively. Old fields were composed of a mixture of native and exotic plant species. Coleopteran family richness and diversity were significantly greater in native prairies than brome fields (P < 0.05), whereas orthopteran species richness and diversity peaked in brome fields. Diversity and richness of all arthropod groups examined were significantly, positively correlated with plant species diversity and richness in drop-trap samples (P < 0.05). Coleopteran family diversity and richness in pitfall samples were positively correlated with abundance of native plants, but orthopteran species diversity and richness were negatively correlated with native plant abundance. Coleopteran and orthopteran responses to land use appeared linked to differences in management practices. Whereas coleopterans appeared most influenced by plant community composition, orthopterans showed sensitivity to mechanical disturbance associated with haying on native prairie. Plant and arthropod group diversities were not consistently correlated, demonstrating that arthropod groups can reflect differences in a landscape that may not be apparent from examining plant communities alone.10abiological assessment10aColeoptera10aindicator species10aOrthoptera1 aJonas, J.1 aWhiles, M.R.1 aCharlton, R.E. uhttp://lter.konza.ksu.edu/content/aboveground-invertebrate-responses-land-management-differences-central-kansas-grassland02245nas a2200157 4500008004100000245010800041210006900149300001200218490000800230520164700238653002201885100001901907700001701926700002001943856012401963 2002 eng d00aAnnual fire, mowing and fertilization effects on two cicadas (Homoptera:Cicadidae) in tallgrass prairie0 aAnnual fire mowing and fertilization effects on two cicadas Homo a90 -1010 v1483 aIn tallgrass prairie, cicadas emerge annually, are abundant and their emergence can be an important flux of energy and nutrients. However, factors influencing the distribution and abundance of these cicadas are virtually unknown. We examined cicada emergence in plots from a long-term (13 y) experimental manipulation involving common tallgrass prairie management practices. The plots were arranged in a factorial experimental design, incorporating annual burning, mowing and fertilization (10 g N m−2 and 1 g P m−2). One cicada species, Cicadetta calliope, responded positively to fire, but negatively to mowing, and was most abundant in plots that were burned, unmowed and fertilized. Increased density of C. calliope in this treatment combination is related, in part, to increased availability of oviposition sites aboveground. Furthermore, C. calliope females from fertilized plots were significantly larger in body size relative to females from unfertilized prairie. Another cicada species, Tibicen aurifera, emerged only from unburned plots. The mechanism underlying this negative response to fire is unclear, but may be related to the presence of standing dead vegetation or improved quality (i.e., N content) of belowground plant tissue in unburned plots. In contrast to C. calliope, the density of T. aurifera was not affected by mowing or fertilization. However, like C. calliope, the body size of T. aurifera females was significantly greater in fertilized plots. Cicada emergence resulted in N flux ranging from 0.05–0.16 g N m−2 in unburned plots, but N flux (as cicada biomass) from annually burned plots was negligible.10atallgrass prairie1 aCallaham, M.A.1 aWhiles, M.R.1 aBlair, John, M. uhttp://lter.konza.ksu.edu/content/annual-fire-mowing-and-fertilization-effects-two-cicadas-homopteracicadidae-tallgrass00618nas a2200145 4500008004100000245014100041210006900182300001100251490000700262653002200269100001600291700001700307700001900324856012900343 2002 eng d00aLife history, secondary production, and ecosystem significance of acridid grasshoppers in annually burned and unburned tallgrass prairie0 aLife history secondary production and ecosystem significance of  a40 -490 v4810atallgrass prairie1 aMeyer, C.K.1 aWhiles, M.R.1 aCharlton, R.E. uhttp://lter.konza.ksu.edu/content/life-history-secondary-production-and-ecosystem-significance-acridid-grasshoppers-annually02937nas a2200229 4500008004100000245009500041210006900136300001200205490000700217520214000224653003102364653001602395653001302411653003702424653001902461653001902480653002502499653002202524100002002546700001702566856012402583 2002 eng d00aMacroinvertebrate production and trophic structure in a tallgrass prairie headwater stream0 aMacroinvertebrate production and trophic structure in a tallgras a97 -1130 v213 aResearch on North American prairie stream communities has lagged behind other regions. We examined the ecosystem significance of the macroinvertebrate community of riffle/run habitats in Kings Creek, a 2nd-order tallgrass prairie stream at Konza Prairie Biological Station (Kansas, USA), by estimating secondary production, benthic organic matter standing stocks, and resource consumption and egestion by functional groups. Annual mean standing stock macroinvertebrate biomass was 2.3 g ash-free dry mass (AFDM)/m2, annual production was 19.7 g AFDM m-2 y-1, and the annual community production/biomass (P/B) ratio was 8.6. Macroinvertebrate production was higher than published estimates for forested streams of similar size, but much lower than that of a Sonoran desert stream. Distribution of production among functional groups was 30% for collector-gatherers, 9% for collector-filterers, 20% for scrapers, 23% for shredders, and 18% for predators, resembling estimates from some forested streams with the exception of higher scraper production. Although detritivorous groups were productive in this prairie stream, they appeared food limited. Consumption estimates indicated shredders and collector-gatherers annually ingested ∼80% and ∼240% of coarse particulate organic matter (CPOM) and fine particulate organic matter (FPOM) standing stocks, respectively. Thus, re-ingestion and/or diet shifts may be common, particularly among collector-gatherers, and the FPOM pool must turn over rapidly. Invertebrate predators also consumed a sizeable portion (∼52%) of prey, whereas scrapers (∼21%) and filterers (<1%) consumed relatively small portions of their respective resources, suggesting top-down influences on these groups. This study indicates that, during a period of relatively stable flow in this prairie stream, macroinvertebrate production and functional structure were roughly intermediate between North American forested and desert systems. Our results underscore the value of secondary production estimates for examining invertebrate communities in an ecosystem context10aAquatic macroinvertebrates10aEnergy flow10aFood web10aKonza Prairie Biological Station10aorganic matter10aPrairie stream10asecondary production10aTrophic structure1 aStagliano, D.M.1 aWhiles, M.R. uhttp://lter.konza.ksu.edu/content/macroinvertebrate-production-and-trophic-structure-tallgrass-prairie-headwater-stream02481nas a2200133 4500008004100000245013300041210006900174300001500243490000700258520191700265100001702182700001802199856013002217 2002 eng d00aRelationships between stream size, suspended particles, and filter-feeding macroinvertebrates in a Great Plains drainage network0 aRelationships between stream size suspended particles and filter a1589 -16000 v313 aSuspended fine particles (seston) are an important component of energy and nutrient cycling in streams, but they can also be pollutants. We examined seston dynamics and filter-feeding macroinvertebrate communities in sites representing headwaters to large rivers in the Kansas River drainage, northeastern KS. Seston samples were collected at least seasonally during low to moderate flows for one year beginning in the summer of 1999, and quality was assessed by determining organic content and C to N ratio. A rapid bioassessment approach was used to examine filter-feeders. Relationships between stream size and seston concentrations were markedly influenced by anthropogenic activities. There was no relationship between total seston concentration and stream size across all sites (r = 0.14, p > 0.05), but a significant, positive relationship was evident when impounded and suburban sites were excluded (r = 0.73, p < 0.01); this same trend was evident for organic and inorganic components. Seasonal patterns of C to N ratio were evident, with generally lower values during winter and highest values in summer. However, seasonal patterns were dampened in suburban sites and virtually absent below impoundments. Filter-feeder richness was correlated with average organic seston concentrations (r = 0.8, p < 0.01), but this relationship was also obscured by impoundments and suburban development. In particular, impoundments had a dramatic, negative effect on richness. Abundance of most hydropsychid caddisfly taxa was positively correlated with organic seston concentration. Results indicate there are significant patterns regarding seston, filter-feeders, and stream size in this Great Plains river system, but patterns are strongly influenced by human activities. These relationships are relevant to management issues regarding suspended particles and the potential development of bioassessment techniques.1 aWhiles, M.R.1 aDodds, W., K. uhttp://lter.konza.ksu.edu/content/relationships-between-stream-size-suspended-particles-and-filter-feeding-macroinvertebrates02485nas a2200169 4500008004100000245012600041210006900167300001300236490000800249520184200257100001702099700001902116700001602135700001402151700001902165856013102184 2001 eng d00aEmergence of periodical cicadas (Magicicada cassini ) from a Kansas riparian forest: densities, biomass and nitrogen flux0 aEmergence of periodical cicadas Magicicada cassini from a Kansas a176 -1870 v1453 aThe 1998 emergence of 17-y periodical cicadas (Magicicada cassini) on Konza Prairie Research Natural Area (KPRNA), Kansas, was quantified using emergence trap transects and counts of emergence holes. Emergence density, biomass (emergence production) and associated nitrogen flux were estimated for the entire 100 ha gallery forest of Kings Creek, the major drainage network on KPRNA. Emergence commenced on 22 May 1998 and lasted for 24 d, with 87% of the individuals emerging within the first 9 d. Males dominated early during the emergence, and the sex ratio for the entire population was estimated at 54:46 male:female. Average emergence abundance and biomass estimated from trap transects located in low areas where cicadas were most abundant were 152/m2 and 34.9 g ash-free dry mass (AFDM)/m2, respectively. Based on emergence hole counts, average density and biomass for the 59 ha of gallery forest where cicadas emerged were 27.2 individuals/m2 and 6.3 g AFDM/m2, and emergence hole densities >100/m2 were evident in low areas of the drainage. Emergence density generally decreased with increasing elevation in the catchment. Belowground to aboveground N flux associated with M. cassini emergence in high density areas was ∼3 g N/m2, and the average for the entire emergence area was 0.63 g N/m2. The total number of individuals that emerged from the Kings Creek riparian forest was estimated at 19.6 million, which represents 4.6 metric tons AFDM and ∼0.5 metric tons N. This linear, fragmented, gallery forest of the Flint Hills supports a high density of M. cassini, and an emergence event constitutes a significant belowground to aboveground flux of energy and nutrients. Thus, the periodical cicada may be an exception to the notion that insects generally do not represent important resource pools at the ecosystem level.1 aWhiles, M.R.1 aCallaham, M.A.1 aMeyer, C.K.1 aBrock, B.1 aCharlton, R.E. uhttp://lter.konza.ksu.edu/content/emergence-periodical-cicadas-magicicada-cassini-kansas-riparian-forest-densities-biomass-and02602nas a2200229 4500008004100000245010700041210006900148300001300217490000800230520182600238653001402064653002102078653001802099653002602117653002002143100001902163700001702182700001602199700001402215700001902229856012402248 2000 eng d00aFeeding ecology and emergence production of annual cicadas (Homoptera: Cicadidae) in tallgrass prairie0 aFeeding ecology and emergence production of annual cicadas Homop a535 -5420 v1233 aThe emergence phenology and feeding ecology of annual cicadas in tallgrass prairie are poorly documented. However, these large insects are abundant, and their annual emergence represents a potentially important flux of energy and nutrients from belowground to aboveground. We conducted a study at Konza Prairie Research Natural Area in eastern Kansas to characterize and quantify cicada emergence and associated energy and nutrient fluxes. We established emergence trap transects in three habitat types (upland prairie, lowland prairie, and riparian forest), and collected cicadas every 3 days from May to September. A subset of trapped cicadas was used for species- and sex-specific mass, nutrient, and stable isotope analyses. Five species were trapped during the study, of which three were dominant. Cicadetta calliope and Tibicen aurifera exhibited significantly higher emergence production in upland prairie than in lowland prairie, and were not captured in forested sites at all. T. dorsata emerged from all three habitat types, and though not significant, showed a trend of greater abundance in lowland grasslands. Two less abundant species, T. pruinosa and T. lyricen, emerged exclusively from forested habitats. Nitrogen fluxes associated with total cicada emergence were estimated to be ∼4 kg N ha–1 year–1 in both grassland habitats, and 1.01 kg N ha–1 year–1 in forested sites. Results of stable isotope analyses showed clear patterns of resource partitioning among dominant cicada species emerging from grassland sites. T. aurifera and C. calliope had δ13C and δ15N signatures indicative of feeding on shallowly rooted C4 plants such as the warm-season grasses dominant in tallgrass prairie ecosystems, whereas T. dorsata signatures suggested preferential feeding on more deeply rooted C3 plants.10agrassland10aInsect emergence10aNutrient flux10aresource partitioning10aStable isotopes1 aCallaham, M.A.1 aWhiles, M.R.1 aMeyer, C.K.1 aBrock, B.1 aCharlton, R.E. uhttp://lter.konza.ksu.edu/content/feeding-ecology-and-emergence-production-annual-cicadas-homoptera-cicadidae-tallgrass02621nas a2200169 4500008004100000245010900041210006900150300001300219490000700232520201400239100001602253700001702269700001402286700001502300700001402315856012202329 2000 eng d00aPatterns of species density and productivity at different spatial scales in herbaceous plant communities0 aPatterns of species density and productivity at different spatia a417 -4270 v893 aA major challenge in evaluating patterns of species richness and productivity involves acquiring data to examine these relationships empirically across a range of ecologically significant spatial scales. In this paper, we use data from herb-dominated plant communities at six Long-Term Ecological Research (LTER) sites to examine how the relationship between plant species density and above-ground net primary productivity (ANPP) differs when the spatial scale of analysis is changed. We quantified this relationship at different spatial scales in which we varied the focus and extent of analysis: (1) among fields within communities, (2) among fields within biomes or biogeographic regions, and (3) among communities within biomes or biogeographic regions. We used species density (D=number of species per m2) as our measure of diversity to have a comparable index across all sites and scales. Although we expected unimodal relationships at all spatial scales, we found that spatial scale influenced the form of the relationship. At the scale of fields within different grassland communities, we detected a significant relationship at only one site (Minnesota old-fields), and it was negative linear. When we expanded the extent of analyses to biogeographic regions (grasslands or North America), we found significant unimodal relationships in both cases. However, when we combined data to examine patterns among community types within different biogeographic regions (grassland, alpine tundra, arctic tundra, or North America), we did not detect significant relationships between species density and ANPP for any region. The results of our analyses demonstrate that the spatial scale of analysis – how data are aggregated and patterns examined – can influence the form of the relationship between species density and productivity. It also demonstrates the need for data sets from a broad spectrum of sites sampled over a range of scales for examining challenging and controversial ecological hypotheses.1 aGross, K.L.1 aWhiles, M.R.1 aGough, L.1 aInouye, R.1 aCox, S.B. uhttp://lter.konza.ksu.edu/content/patterns-species-density-and-productivity-different-spatial-scales-herbaceous-plant02549nas a2200325 4500008004100000245006100041210006100102300001300163490000600176520164900182653002001831653001401851653001901865653002001884653001101904653002201915100001801937700002201955700001801977700001301995700001702008700001502025700001702040700001802057700001602075700001502091700001702106700001702123856008302140 2000 eng d00aQuantification of the nitrogen cycle in a prairie stream0 aQuantification of the nitrogen cycle in a prairie stream a574 -5890 v33 aNitrogen (N) was added for 35 days in the form of 15NH4Cl to Kings Creek on Konza Prairie, Kansas. Standing stocks of N in key compartments (that is, nutrients, detritus, organisms) were quantified, and the amount of labeled N entering the compartments was analyzed. These data were used to calculate turnover and flux rates of N cycling through the food web, as well as nutrient transformation rates. Inorganic N pools turned over much more rapidly in the water column of this stream than in pelagic systems where comparable measurements have been made. As with other systems, the mass of ammonium was low but it was the key compartment mediating nutrient flux through the ecosystem, whereas dissolved organic N, the primary component of N flux through the system, is not actively cycled. Nitrification was also a significant flux of N in the stream, with rates in the water column and surface of benthos accounting for approximately 10% of the total ammonium uptake. Primary consumers assimilated 67% of the inorganic N that entered benthic algae and microbes. Predators acquired 23% of the N that consumers obtained. Invertebrate collectors, omnivorous crayfish (Orconectes spp.), and invertebrate shredders dominated the N flux associated with primary consumers. Mass balance calculations indicated that at least 23% of the 309 mg of 15N added during the 35 days of release was retained within the 210-m stream reach during the release. Overall, the rates of turnover of N in organisms and organic substrata were significantly greater when C:N was low. This ratio may be a surrogate for biological activity with regard to N flux in streams.10aaquatic insects10aC:N ratio10anitrogen cycle10anitrogen export10astream10aTrophic structure1 aDodds, W., K.1 aEvans-White, M.A.1 aGerlanc, N.M.1 aGray, L.1 aGudder, D.A.1 aKemp, M.J.1 aLo'pez, A.L.1 aStagliano, D.1 aStrauss, E.1 aTank, J.L.1 aWhiles, M.R.1 aWollheim, W. uhttp://lter.konza.ksu.edu/content/quantification-nitrogen-cycle-prairie-stream01028nas a2200133 4500008004100000245007500041210006900116300001300185490000700198520055900205100001700764700001700781856009600798 1988 eng d00aA technique for the collection and study of subterranean invertebrates0 atechnique for the collection and study of subterranean invertebr a375 -3760 v333 a

The study of invertebrate communities in ground, well, or cave water is hampered due to the difficulty of observing them in their native habitat. Many collection techniques are destructive and do not give a true indication of actual populations. We have found that the header box of an artificial stream system will serve successfully as an artificial "cave" for the collection and study of subterranean invertebrates. Using this technique, we were able to collect two species of aquatic invertebrates previously unknown to Konza Prairie

1 aHooker, K.L.1 aWhiles, M.R. uhttp://lter.konza.ksu.edu/content/technique-collection-and-study-subterranean-invertebrates