- 1Colorado State University, Department of Biology and Graduate Degree Program in Ecology, Fort Collins, United States of America (melinda.smith@colostate.edu)
- 2University of New Mexico, Department of Biology, Albuquerque, United States of America (scollins@unm.edu)
- *A full list of authors appears at the end of the abstract
We quantified the impacts of four years of nominal (within the historic range of variability) and extreme (1-in-100-year recurrence frequency) droughts on aboveground productivity with the International Drought Experiment (IDE), a coordinated, distributed network of 74 grassland and shrubland sites located on six continents across the globe. We expected that aboveground productivity, a key measure of terrestrial ecosystem functioning, would be impacted progressively (i.e., decline over time) as duration and severity of droughts increased. An alternative prediction is that acclimation may occur, whereby – productivity is either maintained or may even recover when drought is prolonged over multiple years. On average across all IDE sites and irrespective of whether drought was nominal or extreme, aboveground productivity declined significantly in the first of year drought, but the magnitude of loss in productivity did not change in years 2 to 4. Thus, we found evidence overall for acclimation to prolonged drought, and a similar acclimation response was observed with prolonged, nominal drought. Yet, when drought was extreme, progressive losses in ecosystem productivity was observed, with the largest losses observed with increasing drought severity in the third and fourth years of drought. Furthermore, the largest losses in productivity (>70%) were observed when drought was extreme for more than two consecutive years. Our results provide evidence for a strong interaction between drought severity and duration. When drought is within the historic range of variability, grassland and shrubland ecosystems have the potential to acclimate, but when extreme, ecosystems that historically were resistant may experience profound losses in functioning over time. This finding has important implications for terrestrial ecosystem functioning in the future, given forecasts for more severe and longer duration droughts with climate change - ecosystems may shift from being resistant to prolonged drought to experiencing catastrophic losses in ecosystem functioning.
Jeffrey Dukes, Osvaldo Sala, Seth Munson, Maggie Anderson, Meghan Avolio, Anping Chen, Meghan Hayden, Martin Holdrege, Ingrid Slette, Peter Wilfahrt, Kate Wilkins, Claus Beier, Lauchlan Fraser, Anke Jentsch, Michael Loik, Yiqi Luo, Fernando Maestre, Richard Phillips, Sally Power, Laura Yahdjian, Qiang Yu, Angel Chen, Andrew Felton, Laureano Gherardi, Smriti Limbu, Nicholas Lyon, Hamed Abdoli, Mehdi Abedi, Juan Alberti, Antonio Arroyo, Heidi Asbjornsen, Harald Auge, Seton Bachle, Michael Bahn, David Bartholomew, Amgaa Batbaatar, Taryn Bauerle, Karen Beard, Kai Behn, Ilka Beil, Lucio Biancari, Irmgard Blindow, Viviana Bondaruk, Elizabeth Borer, Edward Bork, Carlos Bruschetti, Kerry Byrne, James Cahill, Dianela Calvo, Michele Carbognani, Cameron Carlyle, Karen Castillioni, Miguel Castillo-Garcia, Manjunatha Chandregowda, Scott Chang, Jeff Chieppa, Amber Churchill, Marcus Cianciaruso, Amanda Cordeiro, Sara Cousins ,Daniela Cusack, Sven Dahlke, Pedro Daleo, Lee Dietterich, Maren Dubbert, Nico Eisenhauer, T'ai Forte, Flavia Funk, Darcy Galiano, Aaron Greenville, Siri Haugum, Yann Hautier, Andy Hector, Hugh Henry, Daniela Hoss, Forest Isbell, Samuel Jordan, Yuguang Ke, Eugene Kelly, Sally Koerner, Juergen Kreyling, Alicia Kröpfl, Angelika Kübert, Andrew Kulmatiski, Eric Lamb, Klaus Larsen, Steven Lee, Anja Linstädter, Shirong Liu, Grisel Longo, Alejandro Loydi, Junwei Luan, F. Curtis Lubbe, Andrey Malyshev, Cameron McIntire, Daniel Metcalfe, Malesela Mokoka, Akira Mori, Edwin Mudongo, Gregory Newman, Uffe Nielsen, Raúl Ochoa-Hueso, Rory O'Connor, Romà Ogaya, Gastón Oñatibia, Brooke Osborne, Rafael Otfinowski, Meelis Pärtel, Jesús Pascual, Josep Peñuelas, Pablo Peri, David Pescador, Guadalupe Peter, Alessandro Petraglia, Catherine Picon-Cochard, Valério Pillar, Juan Piñeiro-Guerra, Laura Ploughe, Robert Plowes, Cristy Portales-Reyes, Suzanne Prober, Yolanda Pueyo, Golsa Rahmati, Sasha Reed, Dana Rodríguez, William Rogers, Christiane Roscher, David Rowley, Ana Sánchez, Bráulio Santos, Michael Schellenberg, Michael Scherer-Lorenzen, Eric Seabloom, Ruonan Shen, Baoku Shi, Lara Souza, Andreas Stampfli, Rachel Standish, Marcelo Sternberg, Wei Sun, Marie Sünnemann, Michelle Tedder, Tyson Terry, Pål Thorvaldsen, Katja Tielbörger, Maud Tissink, Matthew Vadeboncoeur, Alejandro Valdecantos, Liesbeth van den Brink, Vigdis Vandvik, Liv Velle, Svenja Wanke, Glenda Wardle, Cunzheng Wei, Christiane Werner, Georg Wiehl, Jennifer Williams, Amelia Wolf, Chong Xu, Xuechen Yang, Jenifer Yost, Alyssa Young, Ping Yue, Juan Zeberio, Michaela Zeiter, Juntao Zhu, and Xiaoan Zuo
How to cite: Smith, M., Ohlert, T., Collins, S., and Knapp, A. and the The International Drought Experiment Network: Drought severity interacts with duration to erode resistance of terrestrial ecosystem productivity, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-6970, https://doi.org/10.5194/egusphere-egu25-6970, 2025.
