Samuels-Crow KE, Peltier DMP, Liu Y, Guo JS, Welker JM, Anderegg WRL, Koch GW, Schwalm C, Litvak M, Shaw JD and Ogle K (2023) The importance of monsoon precipitation for foundation tree species across the semiarid Southwestern U.S. Front. For. Glob. Change 6:1116786. doi: 10.3389/ffgc.2023.1116786
The importance of monsoon precipitation for foundation tree species across the semiarid Southwestern U.S.
|Author:||Samuels-Crow, Kimberly E.1; Peltier, Drew M. P.2,3; Liu, Yao4;|
1School of Informatics, Computing, and Cyber Systems, Northern Arizona University, Flagstaff, AZ, United States
2Department of Biological Sciences, Northern Arizona University, Flagstaff, AZ, United States
3Center for Ecosystem Science and Society, Northern Arizona University, Flagstaff, AZ, United States
4Department of Geography and Environmental Sciences, Northumbria University, Newcastle upon Tyne, United Kingdom
5Arizona Experiment Station, University of Arizona, Tucson, AZ, United States
6Department of Biological Sciences, University of Alaska, Anchorage, AK, United States
7Ecology and Genetics Research Unit, University of Oulu, Oulu, Finland
8Ecology and Genetics Research Unit, University of the Arctic, Rovaniemi, Finland
9School of Biological Sciences, University of Utah, Salt Lake City, UT, United States
10Woodwell Climate Research Center, Falmouth, MA, United States
11Department of Biology, University of New Mexico, Albuquerque, NM, United States
12Rocky Mountain Research Station, USDA Forest Service, Logan, UT, United States
|Online Access:||PDF Full Text (PDF, 3 MB)|
|Persistent link:|| http://urn.fi/urn:nbn:fi-fe20230927137586
|Publish Date:|| 2023-09-27
Forest dynamics in arid and semiarid regions are sensitive to water availability, which is becoming increasingly scarce as global climate changes. The timing and magnitude of precipitation in the semiarid southwestern U.S. (“Southwest”) has changed since the 21st century began. The region is projected to become hotter and drier as the century proceeds, with implications for carbon storage, pest outbreaks, and wildfire resilience. Our goal was to quantify the importance of summer monsoon precipitation for forested ecosystems across this region. We developed an isotope mixing model in a Bayesian framework to characterize summer (monsoon) precipitation soil water recharge and water use by three foundation tree species (Populus tremuloides [aspen], Pinus edulis [piñon], and Juniperus osteosperma [Utah juniper]). In 2016, soil depths recharged by monsoon precipitation and tree reliance on monsoon moisture varied across the Southwest with clear differences between species. Monsoon precipitation recharged soil at piñon-juniper (PJ) and aspen sites to depths of at least 60 cm. All trees in the study relied primarily on intermediate to deep (10–60 cm) moisture both before and after the onset of the monsoon. Though trees continued to primarily rely on intermediate to deep moisture after the monsoon, all species increased reliance on shallow soil moisture to varying degrees. Aspens increased reliance on shallow soil moisture by 13% to 20%. Utah junipers and co-dominant ñons increased their reliance on shallow soil moisture by about 6% to 12%. Nonetheless, approximately half of the post-monsoon moisture in sampled piñon (38–58%) and juniper (47–53%) stems could be attributed to the monsoon. The monsoon contributed lower amounts to aspen stem water (24–45%) across the study area with the largest impacts at sites with recent precipitation. Therefore, monsoon precipitation is a key driver of growing season moisture that semiarid forests rely on across the Southwest. This monsoon reliance is of critical importance now more than ever as higher global temperatures lead to an increasingly unpredictable and weaker North American Monsoon.
Frontiers in forests and global change
|Type of Publication:||
A1 Journal article – refereed
|Field of Science:||
1181 Ecology, evolutionary biology
1172 Environmental sciences
Funding for all field work, stable isotope analysis, and initial model development was provided by NSF Division of Environmental Biology, RAPID #1643245. Funding for further model development was provided by NSF Hydrologic Sciences award EAR1834699.
© 2023 Samuels-Crow, Peltier, Liu, Guo, Welker, Anderegg, Koch, Schwalm, Litvak, Shaw and Ogle. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.