@article {KNZ001771, title = {Above- and below-ground responses of native and invasive prairie grasses to future climate scenarios}, journal = {Botany}, volume = {94}, year = {2016}, pages = {471 - 479}, abstract = {

More intense and frequent droughts, coupled with elevated temperatures, are projected for grasslands worldwide. Although it has been suggested that alterations in temperature and precipitation will increase the success of biological invasions, studies that combine these climate change scenarios are limited. These changes in climate may increase the success of non-native, invasive plant species directly, as these species often possess traits that are favored by variable climates, or indirectly through negative impacts on native vegetation or alterations in soil microbial communities, such as arbuscular mycorrhizal (AM) fungi. The goal of our research was to assess above- and below-ground production and mycorrhizal fungal abundance of functionally similar native and invasive non-native grass species under projected climate-change scenarios. We assessed plant biomass, intra-radical AM root colonization, and relative abundance of extra-radical fungal biomass of two native (Schizachyrium scoparium (Michx.) Nash, Pascopyrum smithii (Rydb.) {\'A}.L{\"o}ve) and two invasive (Bothriochloa ischaemum (L.) Keng, Bromus inermis Leyss.) grass species subjected to increased temperature and decreased soil water availability. Regardless of temperature or soil moisture, the invasive grasses in our study displayed greater seedling growth as compared with paired native species. Invasive grasses were also generally characterized by greater intra-radical colonization by AM fungi, compared with native species. Our data suggest that invasive grasses will continue to be problematic and successfully out-compete native grasses following increased temperatures and reduced water availability, as projected by climate-change models.

}, keywords = {LTER-KNZ, Bothriochloa ischaemum, Bromus imermis, Climate change, Invasive species, Pascopyrum smithii, Schizachyrium scoparium}, doi = {10.1139/cjb-2015-0238}, url = {http://www.nrcresearchpress.com/doi/10.1139/cjb-2015-0238}, author = {E.B. Duell and G.T. Wilson and Hickman, K.R.} } @article {KNZ001663, title = {Experimental evidence that invasive grasses use allelopathic biochemicals as a potential mechanism for invasion: Chemical warfare in nature}, journal = {Plant and Soil}, volume = {385}, year = {2014}, pages = {165 -179}, abstract = {

Background and aims Bothriochloa spp. are non-native warm-season grasses invading native grasslands of the southern and central Great Plains, altering ecological services these grasslands supply. Our study investigated potential allelopathic effects of the invasive grass species B. ischaemum on native grass germination, growth, and survival. Methods Leachate or litter from Andropogon gerardii (native) or B. ischaemum were applied to two native grass species (A. gerardii; Schizachyrium scoparium). Leachate and litter were also added to B. ischaemum and a water control was included. Germination, above- and belowground biomass, and survival were determined. Results Application of B. ischaemum leachate or litter significantly reduced the germination, growth, and survival of both A. gerardii and S. scoparium but had no conspecific effects, while A. gerardii treatments had no effect on any species. Conclusions Bothriochloa spp. may gain a competitive advantage through allelopathic biochemicals. It is unclear if these allelopathic effects directly hinder competitors or indirectly hinder them through alterations in soil microbial communities, however, reductions in germination of native seeds strongly support direct allelopathic effects. Greater phenolic content in native grass leachates suggest allelopathic biochemical production may not be unique to non-native species and may be a mechanism for maintenance of plant species biodiversity in native systems.

}, keywords = {LTER-KNZ, Allelopathy, Bothriochloa spp, Invasive species, Leachate, Leaf litter, Yellow bluestem}, doi = {10.1007/s11104-014-2209-3}, url = {https://link.springer.com/article/10.1007\%2Fs11104-014-2209-3}, author = {Greer, M.J. and G.T. Wilson and Hickman, K.R. and Wilson, S.} } @inbook {KNZ001435, title = {Applying soil ecological knowledge to restore ecosystem services}, booktitle = {Soil Ecology and Ecosystem Services}, year = {2012}, pages = {377 -393}, publisher = {Oxford University Press}, organization = {Oxford University Press}, address = {Oxford, UK}, abstract = {Ecological restoration is human-facilitated improvement of a degraded environment. This chapter synthesizes the relevance of soil ecological knowledge to restoration along a continuum of ecosystem degradation and in the context of novel ecosystems. At one end of the continuum, mining can result in severe soil degradation and contamination with metals. Restoration of mined sites often focuses on decontamination, and success can be affected by soil heterogeneity, organic matter content, and refugia for soil biota that possess biodegradation pathways. Former agricultural sites can exhibit a wide range of soil and ecosystem legacies, with restoration goals ranging from simply reducing erosion with perennial plants to establishing a suite of historic ecosystem attributes and services through the re-introduction of many species. Although recovery of soil structure and function can coincide with plant establishment, knowledge of soil processes and plant{\textendash}soil feedbacks have been applied to promote resource heterogeneity and plant diversity, and to reduce non-native species in restored agricultural systems. Even in relatively undisturbed sites with high legacy of native plants and soil, invasions of undesirable species may occur. Restoration of invaded systems may necessitate knowledge of how invaders impact resource availability and capture, as well as potentially complex multi-trophic interactions and feedbacks with soil. Last, restoration of novel ecosystems with new and self-sustaining assemblages of plant species in no-analog environments may require sophisticated consideration of biogeochemistry, plant population and community dynamics, and soil ecology to reintroduce and sustain native species long extirpated from local environments.}, keywords = {LTER-KNZ, agriculture, Invasive species, mining; novel ecosystem, plant{\textendash}soil feedback, restoration, soil ecological knowledge}, doi = {10.1093/acprof:oso/9780199575923.003.0032}, url = {http://dx.doi.org/10.1093/acprof:oso/9780199575923.003.0032}, author = {S.G. Baer and Heneghan, L. and Eviner, V.}, editor = {Wall, D.} } @article {KNZ001327, title = {Retrospective analysis of fish community change during a half-century of landuse and streamflow changes}, journal = {Journal of the North American Benthological Society}, volume = {29}, year = {2010}, pages = {970 -987}, abstract = {

Ecological thresholds that lead to alternative community states can be exceeded through gradual perturbation or as a result of sudden disturbance. Many Great Plains streams have experienced dramatic changes in their hydrologic regime resulting from water and landuse changes that began as early as 1880. These changes, combined with the presence of many invasive species, have substantially altered the fish communities in this area. We quantified temporal changes in fish communities in 3 large river basins in relation to putative anthropogenic stressors, including increased sediment supply derived from row-crop agriculture (beginning in 1880), habitat fragmentation caused by reservoir construction (beginning in the 1950s), and reduced discharge caused by groundwater withdrawal (beginning in the 1960s). We hypothesized that these abiotic regime shifts, coupled with species invasions, would shift the system from a fish community dominated by lotic (flowing water) species to one dominated by lentic (still water) species. Further, we predicted that the timing and intensity of community change would vary across basins that experienced different types and levels of stressors. Restructuring of fish communities across the 3 river basins was driven primarily by similar increases in lentic species, with only a few declines in several large-river species. Current fish communities in these basins share \<50\% of the species recorded in historic collections, and these differences were driven by species extirpations and invasions. The greatest levels of community divergence over time occurred in western Kansas basins that experienced the most intense groundwater withdrawals and fragmentation by reservoirs. An alarming result from this analysis was the recent (after 1991) expansion of several invasive species in the Arkansas and lower Kansas River basins and the decline or extirpation of several native species where flow regimes are less heavily altered. Accelerating changes in the biota and habitat identified by our retrospective analysis highlight potential complications for restoring the habitat and native fish communities to a previous state.

}, keywords = {LTER-KNZ, biotic homogenization, Hydrology, Invasive species, presence{\textendash}absence data, retrospective analysis, streamflow modification}, doi = {10.1899/09-116.1}, url = {https://www.journals.uchicago.edu/doi/10.1899/09-116.1}, author = {K. B. Gido and W. K. Dodds and Eberle, M.E.} } @article {KNZ001258, title = {Connectivity of the American agricultural landscape: Assessing the national risk of crop pest and disease spread}, journal = {Bioscience}, volume = {59}, year = {2009}, pages = {141 -151}, abstract = {

More than two-thirds of cropland in the United States is devoted to the production of just four crop species\—maize, wheat, soybeans, and cotton\—raising concerns that homogenization of the American agricultural landscape could facilitate widespread disease and pest outbreaks, compromising the national food supply. As a new component in national agricultural risk assessment, we employed a graph-theoretic approach to examine the connectivity of these crops across the United States. We used county crop acreage to evaluate the landscape resistance to transmission\—the degree to which host availability limits spread in any given region\—for pests or pathogens dependent on each crop. For organisms that can disperse under conditions of lower host availability, maize and soybean are highly connected at a national scale, compared with the more discrete regions of wheat and cotton production. Determining the scales at which connectivity becomes disrupted for organisms with different dispersal abilities may help target rapid-response regions and the development of strategic policies to enhance agricultural landscape heterogeneity.

}, keywords = {LTER-KNZ, geographic information systems, graph theory, Invasive species, landscape connectivity, networks}, doi = {https://doi.org/10.1525/bio.2009.59.2.7}, url = {https://academic.oup.com/bioscience/article/59/2/141/228297}, author = {Margosian, M.L. and Garrett, K.A. and Hutchinson, J.M.S. and With, K.A.} }