SY044-08
A multi-site synthesis of impacts of multi-year extreme events on dryland ecosystem resilience
Friday, 11 December 2020: 18:02
Virtual
Amy Hudson1, Debra Peters2, Meghan L Avolio3, John Blair4, Daniel L Childers5, Scott L Collins6, Peter T Doran7, Sarah E Evans8, Michael N Gooseff9, Nancy B Grimm5, Alan Knapp10, Marcy E Litvak11, Melissa Pastore12, Jennifer Rudgers13, Osvaldo Sala14, Eric W. Seabloom15, Gaius R Shaver16 and Nick Haddad17, (1)USDA-ARS, Office of National Programs, Las Cruces, NM, United States, (2)USDA-ARS Jornada Exp. Range, Las Cruces, NM, United States, (3)Johns Hopkins University, Earth and Planetary Sciences, Baltimore, United States, (4)Kansas State University, Manhattan, KS, United States, (5)Arizona State University, Tempe, AZ, United States, (6)Department of Biology, MSC03-2020, University of New Mexico, Albuquerque, NM, United States, (7)Louisiana State University, Baton Rouge, LA, United States, (8)Colorado State University, Fort Collins, CO, United States, (9)University of Colorado at Boulder, Institute of Arctic and Alpine Research, Boulder, CO, United States, (10)Colorado State University, Department of Biology and Graduate Degree Program in Ecology, Fort Collins, CO, United States, (11)University of New Mexico, Biology, Albuquerque, NM, United States, (12)University of Minnesota, Department of Ecology, Evolution, and Behavior, St. Paul, MN, United States, (13)University of New Mexico, Albuquerque, United States, (14)Arizona State University, School of Life Sciences, Tempe, AZ, United States, (15)University of Minnesota Twin Cities, Minneapolis, United States, (16)Marine Bio Lab, Woods Hole, MA, United States, (17)Kellogg Biological Station- Michigan State University, Hickory Corners, United States
Abstract:
Long-term ecological research is uniquely poised to examine the impacts of multi-year extreme events from climate and other environmental drivers on ecosystem resilience. For 8 long-term research (LTER) sites in the midwestern US (CDR, KBS, KNZ), southwestern US (CAP, JRN, SEV) and polar regions (ARC and MCM), representing grassland, cropland, desert, urban, and tundra ecosystems, we used long-term data to determine: 1- how climate drivers and physical processes have changed over the past century, with a focus on multi-year, extreme events, 2- how these diverse dryland ecosystems have responded to these extreme events, and 3- what the implications of these changes and responses are to ecosystem resilience and services.
We found that regions surrounding most sites are experiencing more positive temperature extremes in the last 20 years than over the remaining 65-year record. Temperature interacts with precipitation regimes to influence changes in water availability. For example, the southwestern US is experiencing, on-average, drier soil conditions with sequences of high precipitation years following two decades of wetter conditions, while the midwestern US has experienced wetter soil conditions- with intermittent dry spells- over the past four decades. Effects of extreme events and their interactions were observed (or experimentally designed) at sites as heat waves (CAP, MCM), droughts (JRN, KBS, KNZ, SEV), fire (ARC, CDR, SEV), glacier melt (MCM), flooding (CAP, KNZ, JRN, SEV), dust events (CAP, JRN), and cloud cover changes (MCM). Ecosystem response trajectories leveled off, shifted, or reversed based on the time since event (legacies), and different ecosystems and processes integrated climate-event interactions differently. Future trajectories in ecosystem resilience are expected to depend on these multi-year extreme events interacting with long-term climate variability, and trends and ecosystem properties at the sites.
