@article {6294, title = {Extreme drought impacts have been underestimated in grasslands and shrublands globally}, journal = {Proceedings of the National Academy of Sciences}, volume = {121}, year = {2024}, pages = {e230988112}, keywords = {LTER-KNZ}, doi = {10.1073/pnas.2309881120}, url = {https://pnas.org/doi/10.1073/pnas.2309881120}, author = {M. D. Smith and Wilkins, Kate D. and Holdrege, Martin C. and Wilfahrt, Peter and S.L Collins and Knapp, Alan K. and Sala, Osvaldo E. and Dukes, Jeffrey S. and Phillips, Richard P. and Yahdjian, Laura and Gherardi, Laureano A. and Ohlert, Timothy and Beier, Claus and Fraser, Lauchlan H. and Jentsch, Anke and Loik, Michael E. and Maestre, Fernando T. and Power, Sally A. and Yu, Qiang and Felton, Andrew J. and Munson, Seth M. and Luo, Yiqi and Abdoli, Hamed and Abedi, Mehdi and Alados, Concepci{\'o}n L. and Alberti, Juan and Alon, Moshe and An, Hui and Anacker, Brian and Anderson, Maggie and Auge, Harald and Bachle, Seton and Bahalkeh, Khadijeh and Bahn, Michael and Batbaatar, Amgaa and Bauerle, Taryn and Beard, Karen H. and Behn, Kai and Beil, Ilka and Biancari, Lucio and Blindow, Irmgard and Bondaruk, Viviana Florencia and Borer, Elizabeth T. and Bork, Edward W. and Bruschetti, Carlos Martin and Byrne, Kerry M. and Cahill Jr., James F. and Calvo, Dianela A. and Carbognani, Michele and Cardoni, Augusto and Carlyle, Cameron N. and Castillo-Garcia, Miguel and Chang, Scott X. and Chieppa, Jeff and Cianciaruso, Marcus V. and Cohen, Ofer and Cordeiro, Amanda L. and Cusack, Daniela F. and Dahlke, Sven and Daleo, Pedro and D{\textquoteright}Antonio, Carla M. and Dietterich, Lee H. and S. Doherty, Tim and Dubbert, Maren and Ebeling, Anne and Eisenhauer, Nico and Fischer, Fel{\'\i}cia M. and Forte, T{\textquoteright}ai G. W. and Gebauer, Tobias and Gozalo, Beatriz and Greenville, Aaron C. and Guidoni-Martins, Karlo G. and Hannusch, Heather J. and Vats{\o} Haugum, Siri and Hautier, Yann and Hefting, Mariet and Henry, Hugh A. L. and Hoss, Daniela and Ingrisch, Johannes and Iribarne, Oscar and Isbell, Forest and Johnson, Yari and Jordan, Samuel and Kelly, Eugene F. and Kimmel, Kaitlin and Kreyling, Juergen and Kr{\"o}el-Dulay, Gy{\"o}rgy and Kr{\"o}pfl, Alicia and K{\"u}bert, Angelika and Kulmatiski, Andrew and Lamb, Eric G. and Larsen, Klaus Steenberg and Larson, Julie and Lawson, Jason and Leder, Cintia V. and Linst{\"a}dter, Anja and Liu, Jielin and Liu, Shirong and Lodge, Alexandra G. and Longo, Grisel and Loydi, Alejandro and Luan, Junwei and Curtis Lubbe, Frederick and Macfarlane, Craig and Mackie-Haas, Kathleen and Malyshev, Andrey V. and Maturano-Ruiz, {\'a}n and Merchant, Thomas and Metcalfe, Daniel B. and Mori, Akira S. and Mudongo, Edwin and Newman, Gregory S. and Nielsen, Uffe N. and Nimmo, Dale and Niu, Yujie and Nobre, Paola and O{\textquoteright}Connor, Rory C. and Ogaya, Rom{\`a} and O{\~n}atibia, Gast{\'o}n R. and Orb{\'a}n, Ildik{\'o} and Osborne, Brooke and Otfinowski, Rafael and P{\"a}rtel, Meelis and Pe{\~n}uelas, Josep and Peri, Pablo L. and Peter, Guadalupe and Petraglia, Alessandro and Picon-Cochard, Catherine and Pillar, Val{\'e}rio D. and Pi{\~N}Eiro-Guerra, Juan Manuel and Ploughe, Laura W. and Plowes, Robert M. and Portales-Reyes, Cristy and Prober, Suzanne M. and Pueyo, Yolanda and Reed, Sasha C. and Ritchie, Euan G. and Rodr{\'\i}guez, Ayl{\'e}n and Rogers, William E. and Roscher, Christiane and S{\'a}nchez, Ana M. and Santos, Br{\'a}ulio A. and Scarf{\'o}, Mar{\'\i}a and Seabloom, Eric W. and Shi, Baoku and Souza, Lara and Stampfli, Andreas and Standish, Rachel J. and Sternberg, Marcelo and Sun, Wei and S{\"u}nnemann, Marie and Tedder, Michelle and Thorvaldsen, {\r a}l and Tian, Dashuan and Tielb{\"o}rger, Katja and Valdecantos, Alejandro and van den Brink, Liesbeth and Vandvik, Vigdis and Vankoughnett, Mathew R. and Guri Velle, Liv and Wang, Changhui and Wang, Yi and Wardle, Glenda M. and Werner, Christiane and Wei, Cunzheng and Wiehl, Georg and Williams, Jennifer L. and Wolf, Amelia A. and Zeiter, Michaela and Zhang, Fawei and Zhu, Juntao and Zong, Ning and Zuo, Xiaoan} } @article {6110, title = {Nutrient identity modifies the destabilising effects of eutrophication in grasslands}, journal = {Ecology Letters}, volume = {259}, year = {2022}, pages = {754 - 765}, abstract = {

Nutrient enrichment can simultaneously increase and destabilise plant biomass production, with co-limitation by multiple nutrients potentially intensifying these effects. Here, we test how factorial additions of nitrogen (N), phosphorus (P) and potassium with essential nutrients (K+) affect the stability (mean/standard deviation) of aboveground biomass in 34 grasslands over 7 years. Destabilisation with fertilisation was prevalent but was driven by single nutrients, not synergistic nutrient interactions. On average, N-based treatments increased mean biomass production by 21\–51\% but increased its standard deviation by 40\–68\% and so consistently reduced stability. Adding P increased interannual variability and reduced stability without altering mean biomass, while K+ had no general effects. Declines in stability were largest in the most nutrient-limited grasslands, or where nutrients reduced species richness or intensified species synchrony. We show that nutrients can differentially impact the stability of biomass production, with N and P in particular disproportionately increasing its interannual variability.

}, keywords = {LTER-KNZ}, issn = {1461-023X}, doi = {10.1111/ele.v25.410.1111/ele.13946}, url = {https://onlinelibrary.wiley.com/doi/abs/10.1111/ele.13946}, author = {Carroll, Oliver and Batzer, Evan and Bharath, Siddharth and Borer, Elizabeth T. and Campana, {\'\i}a and Esch, Ellen and Hautier, Yann and Ohlert, Timothy and Seabloom, Eric W. and Adler, Peter B. and Bakker, Jonathan D. and Biederman, Lori and Bugalho, Miguel N. and Caldeira, Maria and Chen, Qingqing and Davies, Kendi F. and Fay, Philip A. and Knops, Johannes M. H. and Kimberly J. Komatsu and Martina, Jason P. and McCann, Kevin S. and Moore, Joslin L. and Morgan, John W. and Muraina, Taofeek O. and Osborne, Brooke and Risch, Anita C. and Stevens, Carly and Wilfahrt, Peter A. and Yahdjian, Laura and MacDougall, Andrew S.}, editor = {Pe{\~n}uelas, Josep} } @article {5970, title = {Negative effects of nitrogen override positive effects of phosphorus on grassland legumes worldwide}, journal = {Proceedings of the National Academy of Sciences}, volume = {118}, year = {2021}, pages = {e2023718118}, keywords = {LTER-KNZ}, doi = {10.1073/pnas.2023718118}, url = {http://www.pnas.org/lookup/doi/10.1073/pnas.2023718118}, author = {Tognetti, Pedro M. and Prober, Suzanne M. and B{\'a}ez, Selene and Chaneton, Enrique J. and Firn, Jennifer and Risch, Anita C. and Schuetz, Martin and Simonsen, Anna K. and Yahdjian, Laura and Borer, Elizabeth T. and Seabloom, Eric W. and Arnillas, Carlos Alberto and Bakker, Jonathan D. and Brown, Cynthia S. and Cadotte, Marc W. and Caldeira, Maria C. and Daleo, Pedro and Dwyer, John M. and Fay, Philip A. and Gherardi, Laureano A. and Hagenah, Nicole and Hautier, Yann and Kimberly J. Komatsu and McCulley, Rebecca L. and Price, Jodi N. and Standish, Rachel J. and Stevens, Carly J. and Wragg, Peter D. and Sankaran, Mahesh} } @article {6003, title = {Why coordinated distributed experiments should go global}, journal = {BioScience}, volume = {71}, year = {2021}, pages = {918 - 927}, keywords = {LTER-KNZ}, doi = {10.1093/biosci/biab033}, url = {https://academic.oup.com/bioscience/article/71/9/918/6259352}, author = {Yahdjian, Laura and Sala, Osvaldo E and Pi{\~N}Eiro-Guerra, Juan Manuel and Alan K. Knapp and Collins, Scott L. and Phillips, Richard P and M. D. Smith} } @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 {KNZ002004, title = {Nutrient addition increases grassland sensitivity to droughts}, journal = {Ecology}, volume = {101}, year = {2020}, pages = {e02981}, abstract = {

Grasslands worldwide are expected to experience an increase in extreme events such as drought, along with simultaneous increases in mineral nutrient inputs as a result of human industrial activities. These changes are likely to interact because elevated nutrient inputs may alter plant diversity and increase the sensitivity to droughts. Dividing a system\’s sensitivity to drought into resistance to change during the drought and rate of recovery after the drought generates insights into different dimensions of the system\’s resilience in the face of drought. Here, we examine the effects of experimental nutrient fertilization and the resulting diversity loss on the resistance to and recovery from severe regional droughts. We do this at 13 North American sites spanning gradients of aridity, five annual grasslands in California, and eight perennial grasslands in the Great Plains. We measured rate of resistance as the change in annual aboveground biomass (ANPP) per unit change in growing season precipitation as conditions declined from normal to drought. We measured recovery as the change in ANPP during the postdrought period and the return to normal precipitation. Resistance and recovery did not vary across the 400-mm range of mean growing season precipitation spanned by our sites in the Great Plains. However, chronic nutrient fertilization in the Great Plains reduced drought resistance and increased drought recovery. In the California annual grasslands, arid sites had a greater recovery postdrought than mesic sites, and nutrient addition had no consistent effects on resistance or recovery. Across all study sites, we found that predrought species richness in natural grasslands was not consistently associated with rates of resistance to or recovery from the drought, in contrast to earlier findings from experimentally assembled grassland communities. Taken together, these results suggest that human-induced eutrophication may destabilize grassland primary production, but the effects of this may vary across regions and flora, especially between perennial and annual-dominated grasslands.

}, keywords = {LTER-KNZ}, doi = {10.1002/ecy.2981}, url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/ecy.2981}, author = {Bharath, Siddharth and E.T. Borer and L.A. Biederman and D.M. Blumenthal and Fay, Philip A. and Gherardi, Laureano A. and Knops, Johannes M. H. and Leakey, Andrew D. B. and Yahdjian, Laura and Seabloom, Eric W.} } @article {KNZ001894, title = {Local loss and spatial homogenization of plant diversity reduce ecosystem multifunctionality}, journal = {Nature Ecology \& Evolution}, volume = {2}, year = {2018}, pages = {50-56}, abstract = {

Biodiversity is declining in many local communities while also becoming increasingly homogenized across space. Experiments show that local plant species loss reduces ecosystem functioning and services, but the role of spatial homogenization of community composition and the potential interaction between diversity at different scales in maintaining ecosystem functioning remains unclear, especially when many functions are considered (ecosystem multifunctionality). We present an analysis of eight ecosystem functions measured in 65 grasslands worldwide. We find that more diverse grasslands\—those with both species-rich local communities (α-diversity) and large compositional differences among localities (β-diversity)\—had higher levels of multifunctionality. Moreover, α- and β-diversity synergistically affected multifunctionality, with higher levels of diversity at one scale amplifying the contribution to ecological functions at the other scale. The identity of species influencing ecosystem functioning differed among functions and across local communities, explaining why more diverse grasslands maintained greater functionality when more functions and localities were considered. These results were robust to variation in environmental drivers. Our findings reveal that plant diversity, at both local and landscape scales, contributes to the maintenance of multiple ecosystem services provided by grasslands. Preserving ecosystem functioning therefore requires conservation of biodiversity both within and among ecological communities.

}, keywords = {LTER-KNZ}, doi = {10.1038/s41559-017-0395-0}, url = {http://www.nature.com/articles/s41559-017-0395-0}, author = {Hautier, Yann and Isbell, Forest and E.T. Borer and Seabloom, Eric W. and Harpole, W. Stanley and Lind, Eric M. and MacDougall, Andrew S. and Stevens, Carly J. and P. Adler and J. Alberti and Bakker, Jonathan D. and Brudvig, Lars A. and Buckley, Yvonne M. and Cadotte, Marc and Caldeira, Maria C. and Chaneton, Enrique J. and Chu, Chengjin and Daleo, Pedro and Dickman, Christopher R. and Dwyer, John M. and Eskelinen, Anu and Fay, Philip A. and Firn, Jennifer and Hagenah, Nicole and Hillebrand, Helmut and Iribarne, Oscar and Kirkman, Kevin P. and Knops, Johannes M. H. and Kimberly J. La Pierre and McCulley, Rebecca L. and J.W. Morgan and P{\"a}rtel, Meelis and Pascual, Jesus and Price, Jodi N. and Prober, Suzanne M. and Risch, Anita C. and Sankaran, Mahesh and Schuetz, Martin and Standish, Rachel J. and Virtanen, Risto and Wardle, Glenda M. and Yahdjian, Laura and Hector, Andy} } @article {KNZ001811, title = {Asymmetric responses of primary productivity to precipitation extremes: A synthesis of grassland precipitation manipulation experiments}, journal = {Global Change Biology}, volume = {23}, year = {2017}, month = {4376-4385}, abstract = {

Climatic changes are altering Earth\&$\#$39;s hydrological cycle, resulting in altered precipitation amounts, increased interannual variability of precipitation, and more frequent extreme precipitation events. These trends will likely continue into the future, having substantial impacts on net primary productivity (NPP) and associated ecosystem services such as food production and carbon sequestration. Frequently, experimental manipulations of precipitation have linked altered precipitation regimes to changes in NPP. Yet, findings have been diverse and substantial uncertainty still surrounds generalities describing patterns of ecosystem sensitivity to altered precipitation. Additionally, we do not know whether previously observed correlations between NPP and precipitation remain accurate when precipitation changes become extreme. We synthesized results from 83 case studies of experimental precipitation manipulations in grasslands worldwide. We used meta-analytical techniques to search for generalities and asymmetries of aboveground NPP (ANPP) and belowground NPP (BNPP) responses to both the direction and magnitude of precipitation change. Sensitivity (i.e., productivity response standardized by the amount of precipitation change) of BNPP was similar under precipitation additions and reductions, but ANPP was more sensitive to precipitation additions than reductions; this was especially evident in drier ecosystems. Additionally, overall relationships between the magnitude of productivity responses and the magnitude of precipitation change were saturating in form. The saturating form of this relationship was likely driven by ANPP responses to very extreme precipitation increases, although there were limited studies imposing extreme precipitation change, and there was considerable variation among experiments. This highlights the importance of incorporating gradients of manipulations, ranging from extreme drought to extreme precipitation increases into future climate change experiments. Additionally, policy and land management decisions related to global change scenarios should consider how ANPP and BNPP responses may differ, and that ecosystem responses to extreme events might not be predicted from relationships found under moderate environmental changes.

}, keywords = {LTER-KNZ}, doi = {10.1111/gcb.13706}, url = {https://onlinelibrary.wiley.com/doi/abs/10.1111/gcb.13706}, author = {K.R. Wilcox and Shi, Zheng and Gherardi, Laureano A. and Lemoine, Nathan P. and Koerner, Sally E. and Hoover, David L. and Bork, Edward and Byrne, Kerry M. and Cahill, James and Scott. L. Collins and Evans, Sarah and Gilgen, Anna K. and Holub, Petr and Jiang, Lifen and Alan K. Knapp and LeCain, Daniel and Liang, Junyi and Garcia-Palacios, Pablo and Pe{\~n}uelas, Josep and Pockman, William T. and M.D. Smith and Sun, Shanghua and White, Shannon R. and Yahdjian, Laura and Zhu, Kai and Luo, Yiqi} } @article {KNZ001842, title = {Asynchrony among local communities stabilises ecosystem function of metacommunities}, journal = {Ecology Letters}, year = {2017}, abstract = {

Temporal stability of ecosystem functioning increases the predictability and reliability of ecosystem services, and understanding the drivers of stability across spatial scales is important for land management and policy decisions. We used species-level abundance data from 62 plant communities across five continents to assess mechanisms of temporal stability across spatial scales. We assessed how asynchrony (i.e. different units responding dissimilarly through time) of species and local communities stabilised metacommunity ecosystem function. Asynchrony of species increased stability of local communities, and asynchrony among local communities enhanced metacommunity stability by a wide range of magnitudes (1\–315\%); this range was positively correlated with the size of the metacommunity. Additionally, asynchronous responses among local communities were linked with species\’ populations fluctuating asynchronously across space, perhaps stemming from physical and/or competitive differences among local communities. Accordingly, we suggest spatial heterogeneity should be a major focus for maintaining the stability of ecosystem services at larger spatial scales.

}, keywords = {LTER-KNZ, Alpha diversity, alpha variability, beta diversity, Biodiversity, CoRRE data base, patchiness, Plant communities, Primary productivity, species synchrony}, doi = {10.1111/ele.12861}, url = {http://onlinelibrary.wiley.com/doi/10.1111/ele.12861/epdf}, author = {K.R. Wilcox and Tredennick, Andrew T. and Koerner, Sally E. and Grman, Emily and Hallett, Lauren M. and M.L. Avolio and Kimberly J. La Pierre and Houseman, Gregory R. and Isbell, Forest and Johnson, David Samuel and Juha M. Alatalo and Baldwin, Andrew H. and Edward W. Bork and Elizabeth H. Boughton and W.D. Bowman and Britton, Andrea J. and Cahill, James F. and Scott. L. Collins and G. Du and Eskelinen, Anu and Gough, Laura and Jentsch, Anke and Kern, Christel and Klanderud, Kari and Alan K. Knapp and Kreyling, Juergen and Luo, Yiqi and McLaren, Jennie R. and Megonigal, Patrick and Onipchenko, Vladimir and Prev{\'e}y, Janet and Price, Jodi N. and Robinson, Clare H. and Sala, Osvaldo E. and M.D. Smith and Soudzilovskaia, Nadejda A. and Souza, Lara and Tilman, David and White, Shannon R. and Xu, Zhuwen and Yahdjian, Laura and Yu, Qiang and Zhang, Pengfei and Zhang, Yunhai}, editor = {Gurevitch, Jessica} }