@article {6070, title = {Prairie stream metabolism recovery varies based on antecedent hydrology across a stream network after a bank-full flood}, journal = {Limnology and Oceanography}, volume = {67}, year = {2022}, pages = {1986-1999}, keywords = {LTER-KNZ}, doi = {10.1002/lno.12182}, url = {https://onlinelibrary.wiley.com/doi/10.1002/lno.12182}, author = {Ruffing, Claire M. and Veach, A.M. and Schechner, Anne and R{\"u}egg, Janine and Trentman, Matt T. and W. K. Dodds} } @article {KNZ001724, title = {Increasing fish taxonomic and functional richness affects ecosystem properties of small headwater prairie streams}, journal = {Freshwater Biology}, volume = {61}, year = {2016}, pages = {887{\textendash}898}, abstract = {

1. Stream fish can regulate their environment through direct and indirect pathways, and the relative influence of communities with different taxonomic and functional richness on ecosystem properties likely depends on habitat structure. Given this complexity, it is not surprising that observational studies of how stream fish communities influence ecosystems have shown mixed results. 2. In this study, we evaluated the effect of an observed gradient of taxonomic (zero, one, two or three species) and functional (zero, one or two groups) richness of fishes on several key ecosystem properties in experimental stream mesocosms. Our study simulated small (less than two metres wide) headwater prairie streams with a succession of three pool-riffle structures (upstream, middle and downstream) per mesocosm. Ecosystem responses included chlorophyll a from floating algal mats and benthic algae, benthic organic matter, macroinvertebrates (all as mass per unit area), algal filament length and stream metabolism (photosynthesis and respiration rate). Ecosystem responses were analysed individually using general linear mixed models. 3. Significant treatment (taxonomic and functional richness) by habitat (pools and riffles) interactions were found for all but one ecosystem response variable. After accounting for location (upstream, middle and downstream) effects, the presence of one or two grazers resulted in shorter mean algal filament lengths in pools compared to no-fish controls. These observations suggest grazers can maintain short algal filaments in pools, which may inhibit long filaments from reaching the surface. Accordingly, floating algal mats decreased in mid- and downstream locations in grazer treatment relative to no-fish controls. 4. At the scale of the entire reach, gross primary productivity and respiration were greater in treatments with two grazer species compared to mixed grazer/insectivore or control treatments. 5. The distribution of stream resources across habitat types and locations within a reach can therefore be influenced by the taxonomic and functional composition of fishes in small prairie streams. Thus, disturbances that alter diversity of these systems might have unexpected ecosystem-level consequences.

}, keywords = {LTER-KNZ}, doi = {10.1111/fwb.12752}, url = {https://onlinelibrary.wiley.com/doi/abs/10.1111/fwb.12752}, author = {Martin, E.D. and K. B. Gido and Bello, N. and W. K. Dodds and Veach, A.M.} } @article {KNZ001762, title = {Spatial and successional dynamics of microbial biofilm communities in a grassland stream ecosystem}, journal = {Molecular Ecology}, volume = {25}, year = {2016}, pages = {4674 - 4688}, abstract = {Biofilms represent a metabolically active and structurally complex component of freshwater ecosystems. Ephemeral prairie streams are hydrologically harsh and prone to frequent perturbation. Elucidating both functional and structural community changes over time within prairie streams provides a general understanding of microbial responses to environmental disturbance. We examined microbial succession of biofilm communities at three sites in a third-order stream at Konza Prairie over a 2- to 64-day period. Microbial abundance (bacterial abundance, chlorophyll a concentrations) increased and never plateaued during the experiment. Net primary productivity (net balance of oxygen consumption and production) of the developing biofilms did not differ statistically from zero until 64 days suggesting a balance of the use of autochthonous and allochthonous energy sources until late succession. Bacterial communities (MiSeq analyses of the V4 region of 16S rRNA) established quickly. Bacterial richness, diversity and evenness were high after 2 days and increased over time. Several dominant bacterial phyla (Beta-, Alphaproteobacteria, Bacteroidetes, Gemmatimonadetes, Acidobacteria, Chloroflexi) and genera (Luteolibacter, Flavobacterium, Gemmatimonas, Hydrogenophaga) differed in relative abundance over space and time. Bacterial community composition differed across both space and successional time. Pairwise comparisons of phylogenetic turnover in bacterial community composition indicated that early-stage succession (<=16 days) was driven by stochastic processes, whereas later stages were driven by deterministic selection regardless of site. Our data suggest that microbial biofilms predictably develop both functionally and structurally indicating distinct successional trajectories of bacterial communities in this ecosystem.}, keywords = {LTER-KNZ}, doi = {10.1111/mec.13784}, url = {https://onlinelibrary.wiley.com/doi/abs/10.1111/mec.13784}, author = {Veach, A.M. and Stagen, J.C. and Brown, S.P. and W. K. Dodds and A. Jumpponen} } @phdthesis {KNZ001704, title = {Dynamics of microbial community structure and function in a tallgrass prairie ecosystem}, volume = {PhD. Dissertation}, year = {2015}, school = {Kansas State University}, type = {Ph.D. Thesis}, address = {Manhattan, KS}, abstract = {

Due to agricultural practices and urbanization, tallgrass prairie ecosystems have become threatened as \< 5\% of its historical coverage exists today. The small remainder of praire that does exist is further threatened by the encroachment of woody plant species. Woody plant encroachment may not only alter prairie ecosystem function, but also prairie microbial communities responsible for these functional processes. Further, prairies are high disturbance ecosystems, especially prairie streams which are hydrologically harsh. They support communities that frequently undergo succession due to recurring flood and drought conditions, yet little is known about the response of microbial communities to these disturbances. In my dissertation, I first address the degree of woody vegetation expansion in riparian corridors (parallel to streams) in watersheds with variable fire frequency and grazing. I found that the rate of riparian woody expansion declines with higher fire intervals and is not affected by grazing, but even annual burns may not prevent woody plant expansion in riparian zones from occurring. Second, I quantified the effect of using restorations of riparian corridors, through removal of woody plants, on physical, chemical, and microbial community (bacteria and fungi) dynamics across stream to upslope soils. Removal restoration causes a decrease in NH$_{4}$$^{+}$ and soil water content, and causes streams and upslope soils to become similar in fungal community richness unlike forested landscapes. Bacterial communities were minimally impacted by removals, but were highly structured among stream to upslope soils due to multiple environmental gradients (i.e., pH, NO$_{3}$$^{-}$, soil moisture). Lastly, I examined the successional development of biofilm-associated microbial communities in a prairie stream from both a functional and structural perspective. I found that biofilm microbes exhibited strong successional trajectories, with communities developing towards net autotrophy and therefore becoming reliant upon in-stream derived carbon. Further, bacterial communities displayed spatial differences, but much stronger temporal patterns in community composition were detected. These studies highlight how woody plant encroachment may influence stream ecosystems in addition to spatiotemporal trends in microbial community assembly.

}, keywords = {LTER-KNZ, Microbial communities; Woody encroachment; Bacteria; Fungi; Biofilms; Stream}, url = {http://krex.k-state.edu/dspace/bitstream/handle/2097/19145/AllisonVeach2015.pdf?sequence=1\&isAllowed=y}, author = {Veach, A.M.} } @article {KNZ001636, title = {Scraping the bottom of the barrel: are rare high throughput sequences artifacts?}, journal = {Fungal Ecology}, volume = {13}, year = {2015}, pages = {221 -225}, abstract = {

Metabarcoding data generated using next-generation sequencing (NGS) technologies are overwhelmed with rare taxa and skewed in Operational Taxonomic Unit (OTU) frequencies comprised of few dominant taxa. Low frequency OTUs comprise a rare biosphere of singleton and doubleton OTUs, which may include many artifacts. We present an in-depth analysis of global singletons across sixteen NGS libraries representing different ribosomal RNA gene regions, NGS technologies and chemistries. Our data indicate that many singletons (average of 38 \% across gene regions) are likely artifacts or potential artifacts, but a large fraction can be assigned to lower taxonomic levels with very high bootstrap support (\∼32 \% of sequences to genus with \≥90 \% bootstrap cutoff). Further, many singletons clustered into rare OTUs from other datasets highlighting their overlap across datasets or the poor performance of clustering algorithms. These data emphasize a need for caution when discarding rare sequence data en masse: such practices may result in throwing the baby out with the bathwater, and underestimating the biodiversity. Yet, the rare sequences are unlikely to greatly affect ecological metrics. As a result, it may be prudent to err on the side of caution and omit rare OTUs prior to downstream analyses.

}, keywords = {LTER-KNZ, fungi, High-throughput sequencing, Rare biosphere, Singleton}, doi = {10.1016/j.funeco.2014.08.006}, url = {https://www.sciencedirect.com/science/article/abs/pii/S1754504814001068?via\%3Dihub}, author = {Brown, S.P. and Veach, A.M. and Rigdon-Huss, A.R. and Grond, K. and Lickteig, S.K. and Lothamer, K. and Oliver, A.K. and A. Jumpponen} } @article {KNZ001703, title = {Woody plant encroachment, and its removal, impact bacterial and fungal communities across stream and terrestrial habitats in a tallgrass prairie ecosystem}, journal = {FEMS Microbiology Ecology}, volume = {91}, year = {2015}, month = {Dec-10-2015}, pages = {fiv109}, abstract = {Woody plant encroachment has become a global threat to grasslands and has caused declines in aboveground richness and changes in ecosystem function; yet we have a limited understanding on the effects of these phenomena on belowground microbial communities. We completed riparian woody plant removals at Konza Prairie Biological Station, Kansas and collected soils spanning land{\textendash}water interfaces in removal and woody vegetation impacted areas. We measured stream sediments and soils for edaphic variables (C and N pools, soil water content, pH) and bacterial (16S rRNA genes) and fungal (ITS2 rRNA gene repeat) communities using Illumina MiSeq metabarcoding. Bacterial richness and diversity decreased with distance from streams. Fungal richness decreased with distance from the stream in wooded areas, but was similar across landscape position while Planctomycetes and Basidiomycota relative abundance was lower in removal areas. Cyanobacteria, Ascomycota, Chytridiomycota and Glomeromycota relative abundance was greater in removal areas. Ordination analyses indicated that bacterial community composition shifted more across land{\textendash}water interfaces than fungi yet both were marginally influenced by treatment. This study highlights the impacts of woody encroachment restoration on grassland bacterial and fungal communities which likely subsequently affects belowground processes and plant health in this ecosystem.}, keywords = {LTER-KNZ, bacterial communities, fungal communities, land{\textendash}water interface, tallgrass prairie, woody encroachment}, doi = {10.1093/femsec/fiv109}, url = {http://femsec.oxfordjournals.org/lookup/doi/10.1093/femsec/fiv109}, author = {Veach, A.M. and W. K. Dodds and A. Jumpponen} } @article {KNZ001625, title = {Fire and grazing influences on rates of riparian woody plant expansion along grassland streams}, journal = {PLOS ONE}, volume = {9:e106922}, year = {2014}, abstract = {

Grasslands are threatened globally due to the expansion of woody plants. The few remaining headwater streams within tallgrass prairies are becoming more like typical forested streams due to rapid conversion of riparian zones from grassy to wooded. Forestation can alter stream hydrology and biogeochemistry. We estimated the rate of riparian woody plant expansion within a 30 m buffer zone surrounding the stream bed across whole watersheds at Konza Prairie Biological Station over 25 years from aerial photographs. Watersheds varied with respect to experimentally-controlled fire and bison grazing. Fire frequency, presence or absence of grazing bison, and the historical presence of woody vegetation prior to the study time period (a proxy for proximity of propagule sources) were used as independent variables to predict the rate of riparian woody plant expansion between 1985 and 2010. Water yield was estimated across these years for a subset of watersheds. Riparian woody encroachment rates increased as burning became less frequent than every two years. However, a higher fire frequency (1\–2 years) did not reverse riparian woody encroachment regardless of whether woody vegetation was present or not before burning regimes were initiated. Although riparian woody vegetation cover increased over time, annual total precipitation and average annual temperature were variable. So, water yield over 4 watersheds under differing burn frequencies was quite variable and with no statistically significant detected temporal trends. Overall, burning regimes with a frequency of every 1\–2 years will slow the conversion of tallgrass prairie stream ecosystems to forested ones, yet over long time periods, riparian woody plant encroachment may not be prevented by fire alone, regardless of fire frequency.

}, keywords = {LTER-KNZ, Anthrax, Bacillus anthracis, Bacterial spores, Cytokines, Edema, Immune response, Innate immune system, Lungs}, doi = {10.1371/journal.pone.0106922}, url = {https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0106922}, author = {Veach, A.M. and W. K. Dodds and Skibbee, A.} }