@article {6112, title = {Nutrient enrichment increases invertebrate herbivory and pathogen damage in grasslands}, journal = {Journal of Ecology}, volume = {110}, year = {2022}, pages = {327 - 339}, keywords = {LTER-KNZ}, doi = {10.1111/1365-2745.13801}, url = {https://besjournals.onlinelibrary.wiley.com/doi/full/10.1111/1365-2745.13801}, author = {Ebeling, Anne and Strauss, Alex T. and Adler, Peter B. and Arnillas, Carlos A. and Barrio, ~C. and Biederman, Lori A. and Borer, Elizabeth T. and Bugalho, Miguel N. and Caldeira, ~C. and Cadotte, Marc W. and Daleo, Pedro and Eisenhauer, Nico and Eskelinen, Anu and Fay, Philip A. and Firn, Jennifer and Graff, Pamela and Hagenah, Nicole and Haider, Sylvia and Kimberly J. Komatsu and McCulley, ~L. and Mitchell, Charles E. and Moore, Joslin L. and Pascual, Jesus and Peri, Pablo L. and Power, Sally A. and Prober, Suzanne M. and Risch, ~C. and Roscher, Christiane and Sankaran, Mahesh and Seabloom, ~W. and Schielzeth, Holger and Sch{\"u}tz, Martin and Speziale, Karina L. and Tedder, Michelle and Virtanen, Risto and Blumenthal, Dana M.} } @article {KNZ002029, title = {Global impacts of fertilization and herbivore removal on soil net nitrogen mineralization are modulated by local climate and soil properties}, journal = {Global Change Biology}, volume = {26}, year = {2020}, abstract = {

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

}, keywords = {LTER-KNZ}, doi = {10.1111/gcb.15308}, url = {https://onlinelibrary.wiley.com/doi/full/10.1111/gcb.15308}, author = {Risch, Anita C. and Zimmermann, Stefan and Moser, Barbara and Sch{\"u}tz, Martin and Hagedorn, Frank and Firn, Jennifer and Fay, Philip A. and Adler, Peter B. and Biederman, Lori A. and J. M. Blair and Borer, Elizabeth T. and Broadbent, Arthur A. D. and Brown, Cynthia S. and Cadotte, Marc W. and Caldeira, Maria C. and Davies, Kendi F. and Virgilio, Augustina and Eisenhauer, Nico and Eskelinen, Anu and Knops, Johannes M. H. and MacDougall, Andrew S. and McCulley, Rebecca L. and Melbourne, Brett A. and Moore, Joslin L. and Power, Sally A. and Prober, Suzanne M. and Seabloom, Eric W. and Siebert, Julia and Silveira, Maria L. and Speziale, Karina L. and Stevens, Carly J. and Tognetti, Pedro M. and Virtanen, Risto and Yahdjian, Laura and Ochoa-Hueso, Raul} } @article {KNZ001882, title = {Spatial heterogeneity in species composition constrains plant community responses to herbivory and fertilisation}, journal = {Ecology Letters}, volume = {21}, year = {2018}, pages = {1364 -1371}, abstract = {

Environmental change can result in substantial shifts in community composition. The associated immigration and extinction events are likely constrained by the spatial distribution of species. Still, studies on environmental change typically quantify biotic responses at single spatial (time series within a single plot) or temporal (spatial beta diversity at single time points) scales, ignoring their potential interdependence. Here, we use data from a global network of grassland experiments to determine how turnover responses to two major forms of environmental change \– fertilisation and herbivore loss \– are affected by species pool size and spatial compositional heterogeneity. Fertilisation led to higher rates of local extinction, whereas turnover in herbivore exclusion plots was driven by species replacement. Overall, sites with more spatially heterogeneous composition showed significantly higher rates of annual turnover, independent of species pool size and treatment. Taking into account spatial biodiversity aspects will therefore improve our understanding of consequences of global and anthropogenic change on community dynamics.

}, keywords = {LTER-KNZ}, doi = {10.1111/ele.13102}, url = {https://onlinelibrary.wiley.com/doi/pdf/10.1111/ele.13102}, author = {Hodapp, Dorothee and E.T. Borer and Harpole, W. Stanley and Lind, Eric M. and Seabloom, Eric W. and P. Adler and J. Alberti and Arnillas, Carlos A. and J.D. Bakker and L.A. Biederman and Cadotte, Marc and Cleland, Elsa E. and Scott. L. Collins and Fay, Philip A. and Firn, Jennifer and Hagenah, Nicole and Hautier, Yann and Iribarne, Oscar and Knops, Johannes M. H. and McCulley, Rebecca L. and MacDougall, Andrew and Joslin L. Moore and J.W. Morgan and Mortensen, Brent and Kimberly J. La Pierre and Risch, Anita C. and Sch{\"u}tz, Martin and Peri, Pablo and Stevens, Carly J. and Wright, Justin and Hillebrand, Helmut}, editor = {Gurevitch, Jessica} } @article {KNZ001789, title = {Consistent responses of soil microbial communities to elevated nutrient inputs in grasslands across the globe}, journal = {Proceedings of the National Academy of Sciences}, volume = {112}, year = {2015}, pages = {10967 - 10972}, abstract = {

Soil microorganisms are critical to ecosystem functioning and the maintenance of soil fertility. However, despite global increases in the inputs of nitrogen (N) and phosphorus (P) to ecosystems due to human activities, we lack a predictive understanding of how microbial communities respond to elevated nutrient inputs across environmental gradients. Here we used high-throughput sequencing of marker genes to elucidate the responses of soil fungal, archaeal, and bacterial communities using an N and P addition experiment replicated at 25 globally distributed grassland sites. We also sequenced metagenomes from a subset of the sites to determine how the functional attributes of bacterial communities change in response to elevated nutrients. Despite strong compositional differences across sites, microbial communities shifted in a consistent manner with N or P additions, and the magnitude of these shifts was related to the magnitude of plant community responses to nutrient inputs. Mycorrhizal fungi and methanogenic archaea decreased in relative abundance with nutrient additions, as did the relative abundances of oligotrophic bacterial taxa. The metagenomic data provided additional evidence for this shift in bacterial life history strategies because nutrient additions decreased the average genome sizes of the bacterial community members and elicited changes in the relative abundances of representative functional genes. Our results suggest that elevated N and P inputs lead to predictable shifts in the taxonomic and functional traits of soil microbial communities, including increases in the relative abundances of faster-growing, copiotrophic bacterial taxa, with these shifts likely to impact belowground ecosystems worldwide.

}, keywords = {LTER-KNZ, Fertilization, shotgun metagenomics, Soil bacteria, Soil ecology, Soil fungi}, doi = {10.1073/pnas.1508382112}, url = {https://www.pnas.org/content/112/35/10967}, author = {Leff, J.W. and Jones, S.E. and Prober, S.M. and Barber{\'a}n, A. and E.T. Borer and Firn, J.L. and Harpole, W.S. and Hobbie, S.E. and Hofmockel, K.S. and Knops, J.M.H. and McCulley, R.L. and Kimberly J. La Pierre and A. Risch and Seabloom, E.W. and Sch{\"u}tz, Martin and Steenbock, C. and Stevens, C.J. and Fierer, N.} }