@article{b76c2dcb3e444a90b8c59ed3626e1ac2,
title = "Warm, dry conditions inhibit aspen growth, but tree growth and size predict mortality risk in the southwestern United States",
abstract = "Widespread, rapid aspen (Populus tremuloides Michx.) mortality since the beginning of the 21st century, sometimes called sudden aspen decline (SAD), has been documented in many locations across North America, but it has been particularly pronounced in the southwestern United States. We investigated the relationship among aspen growth, mortality, and climate across three forest types in northern Arizona using cross-dated tree-ring samples from 126 live and 132 dead aspens. Aspen growth was negatively correlated with warm temperatures and positively associated with higher precipitation. Using survival analysis techniques to investigate the links between aspen mortality, tree traits, and climatic conditions, we found that tree traits played a larger role in mortality risk than climate factors. Trees with larger diameters, older trees, and trees with faster growth rates over the past 50 years had a reduced risk of mortality. Management actions aimed at maintaining the most vigorous, fastest growing aspen in the region could help mitigate the impacts of a warmer, drier future.",
keywords = "Arizona, Aspen, Climate, Mortality, Populus tremuloides",
author = "Ireland, {Kathryn B.} and Moore, {Margaret M.} and Fule, {Peter Z.} and Yocom, {Larissa L.} and Zegler, {Thomas J.}",
note = "Funding Information: We thank the staff and students at Northern Arizona University{\textquoteright}s (NAU) Ecological Restoration Institute, especially Don Nor-mandin and Scott Curran. The Williams Ranger District of the Kaibab National Forest provided permission to do the work and valuable logistical assistance. We benefited from statistical advice from Roy St. Laurent with NAU{\textquoteright}s Statistical Consulting Lab. We also thank Amanda Stan in NAU{\textquoteright}s Department of Geography, Planning and Recreation for assistance with ARSTAN and for providing comments on early drafts of this manuscript. Robert Keane and Signe Leirfallom at the USDA Forest Service Missoula Fire Sciences Laboratory provided assistance with dendrochronological cross-dating and measurement. Mary Lou Fairweather with the USDA Forest Service Arizona Zone of Forest Health Protection program provided useful advice and assistance. George Koch with NAU{\textquoteright}s Biological Sciences Department and two anonymous reviewers provided constructive comments on the manuscript. This work was supported by NAU{\textquoteright}s School of Forestry Mission Research program (McIntire-Stennis), a fellowship through Science Foundation Arizona, USDA Forest Service, Rocky Mountain Research Station Award 08-JV-11221633-244 and USDA Forest Service, Forest Health Monitoring Program, Award INT-EM-B-10-04, and the Lucking Family Foundation. Publisher Copyright: {\textcopyright} 2020 Canadian Science Publishing. All rights reserved.",
year = "2020",
doi = "10.1139/cjfr-2019-0222",
language = "English (US)",
volume = "50",
pages = "1206--1214",
journal = "Canadian Journal of Forest Research",
issn = "0045-5067",
publisher = "National Research Council of Canada",
number = "11",
}