@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 {KNZ001863, title = {Asymmetric responses of primary productivity to altered precipitation simulated by ecosystem models across three long-term grassland sites}, journal = {Biogeosciences}, volume = {15}, year = {2018}, pages = {3421 - 3437}, abstract = {

Field measurements of aboveground net primary productivity (ANPP) in temperate grasslands suggest that both positive and negative asymmetric responses to changes in precipitation (P) may occur. Under normal range of precipitation variability, wet years typically result in ANPP gains being larger than ANPP declines in dry years (positive asymmetry), whereas increases in ANPP are lower in magnitude in extreme wet years compared to reductions during extreme drought (negative asymmetry). Whether the current generation of ecosystem models with a coupled carbon\–water system in grasslands are capable of simulating these asymmetric ANPP responses is an unresolved question. In this study, we evaluated the simulated responses of temperate grassland primary productivity to scenarios of altered precipitation with 14 ecosystem models at three sites: Shortgrass steppe (SGS), Konza Prairie (KNZ) and Stubai Valley meadow (STU), spanning a rainfall gradient from dry to moist. We found that (1)\ the spatial slopes derived from modeled primary productivity and precipitation across sites were steeper than the temporal slopes obtained from inter-annual variations, which was consistent with empirical data; (2)\ the asymmetry of the responses of modeled primary productivity under normal inter-annual precipitation variability differed among models, and the mean of the model ensemble suggested a negative asymmetry across the three sites, which was contrary to empirical evidence based on filed observations; (3)\ the mean sensitivity of modeled productivity to rainfall suggested greater negative response with reduced precipitation than positive response to an increased precipitation under extreme conditions at the three sites; and (4)\ gross primary productivity (GPP), net primary productivity (NPP), aboveground NPP (ANPP) and belowground NPP (BNPP) all showed concave-down nonlinear responses to altered precipitation in all the models, but with different curvatures and mean values. Our results indicated that most models overestimate the negative drought effects and/or underestimate the positive effects of increased precipitation on primary productivity under normal climate conditions, highlighting the need for improving eco-hydrological processes in those models in the future.

}, keywords = {LTER-KNZ}, doi = {10.5194/bg-15-3421-2018}, url = {https://www.biogeosciences.net/15/3421/2018/}, author = {Wu, Donghai and Ciais, Philippe and Viovy, Nicolas and Alan K. Knapp and K.R. Wilcox and Michael Bahn and M.D. Smith and Vicca, Sara and Fatichi, Simone and Zscheischler, Jakob and He, Yue and Li, Xiangyi and Ito, Akihiko and Arneth, Almut and Harper, Anna and Ukkola, Anna and Paschalis, Athanasios and Poulter, Benjamin and Peng, Changhui and Ricciuto, Daniel and Reinthaler, David and Chen, Guangsheng and Tian, Hanqin and Genet, {\'e}l{\`e}ne and Mao, Jiafu and Ingrisch, Johannes and Nabel, Julia E. S. M. and Pongratz, Julia and Lena R. Boysen and Kautz, Markus and Schmitt, Michael and Meir, Patrick and Zhu, Qiuan and R. Hasibeder and Sippel, Sebastian and Dangal, Shree R. S. and Sitch, Stephen and Shi, Xiaoying and Wang, Yingping and Luo, Yiqi and Liu, Yongwen and Piao, Shilong} }