Climate Change, Drought and Tree Mortality: Pattern, Process, and Prediction

Tuesday, August 6, 2013: 8:00 AM-11:30 AM
101A, Minneapolis Convention Center
Henry D. Adams
Alison Macalady and A. Park Williams
William R. L. Anderegg
Increased tree mortality rates associated with drought and elevated temperature is emerging as a global phenomenon that could be exacerbated with climate change. However spatial patterns and processes related to both the causes and consequences of tree mortality during drought are poorly understood. Forests exert a strong influence on earth system processes that is disproportional to their extent: They account for a large portion of the terrestrial carbon sink, greatly affect landscape energy balance, and strongly influence hydrological cycles. It follows that widespread increases in tree mortality due to drought and higher temperatures could severely disrupt ecological functioning of forests and their climate regulation services to society. However, due to large gaps in our understanding of tree mortality processes, ecosystem models at a variety of scales (including coupled vegetation-climate models) are not currently effective at predicting tree death or its consequences. Rising recognition of the importance of tree mortality over the past 5 years has prompted much research aimed at elucidating the patterns, processes, and prediction of this forest disturbance. Work focused on the pattern of tree mortality includes developing a monitoring system for rapid detection of forest die-off, quantifying landscape patterns of tree mortality, and relating these patterns to causes. Process-based research on tree mortality includes experimental and observational determination of the physiological mechanism and other causal agents, as well as the consequences of tree mortality for ecosystems, including changes in nutrient, carbon, water, and energy budgets that can affect biosphere-earth system interactions, and the relationships between tree mortality and other forest disturbances. Predictive tree mortality research integrates knowledge of patterns and processes in an effort to understand past disturbance and anticipate climate change effects on forests. This session aims to highlight recent work on the cutting edge of a wide range of tree mortality research. Our goal is to synthesize current and advance future tree mortality research by convening researchers from across an array of ecological sub-disciplines to present their current work on this pressing issue.
8:00 AM
 Towards a consistent approach for assessing drought risk to terrestrial carbon stores
Anthony O'Grady, CSIRO; Patrick Mitchell, CSIRO; Libby Pinkard, CSIRO; Jody Bruce, CSIRO; Michael Battaglia, CSIRO
8:20 AM
 Pre-disposing factors leading to drought-induced mortality in broad-leaved evergreens
Melanie Zeppel, Macquarie University; Henry D. Adams, Los Alamos National Laboratory; David T. Tissue, Hawkesbury Institute for the Environment, University of Western Sydney, Richmond NSW 2753, Australia; Belinda E. Medlyn, Macquarie University; Adam West, University of Cape Town; Nate G. McDowell, Los Alamos National Laboratory
8:40 AM
 The role of phloem failure in tree mortality during drought
Sanna Sevanto, Los Alamos National Laboratory; Nate G. McDowell, Los Alamos National Laboratory; L. Turin Dickman, Los Alamos National Laboratory; Teemu Holtta, University of Helsinki; Robert E. Pangle, University of New Mexico; William T. Pockman, University of New Mexico
9:00 AM
 Carbon and energy balance consequences of widespread mortality in piñon-juniper woodlands
Marcy E. Litvak, University of New Mexico; Timothy Hilton, University of New Mexico; Daniel J. Krofcheck, University of New Mexico; Andrew M. Fox, National Ecological Observatory Network; Robert Sinsabaugh, University of New Mexico; Nathan McDowell, Los Alamos National Laboratory; Thom Rahn, Los Alamos National Laboratory; Amy Neuenschwander, Universit of Texas
9:20 AM
 Causes and consequences of bark beetle-induced mortality on water, carbon, and nitrogen cycling
Brent E. Ewers, University of Wyoming; D. Scott Mackay, SUNY-Buffalo; Scott D. Peckham, University of Wyoming; Elise Pendall, University of Wyoming; David Reed, University of Wyoming; John M. Frank, Rocky Mountain Research Station, U.S. Forest Service; William J. Massman, Rocky Mountain Research Station, U.S. Forest Service; Urszula Norton, University of Wyoming; Bujidmaa Borkhuu, University of Wyoming; Faith N. Whitehouse, University of Wyoming; Nick Brown, University of Wyoming; Andrew King, University of Wyoming; Carmela Rosaria Guadagno, University of Wyoming; Joel Biederman, University of Arizona; Paul D. Brooks, University of Arizona
9:40 AM
10:10 AM
 Predicting mortality of Pinus edulis during drought using growth and resin duct anatomy
Alison Macalady, University of Arizona; Matthias Kläy, ETH Zurich; Harald Bugmann, ETH Zurich; Monica L. Gaylord, Northern Arizona University; Nathan English, James Cook University; Craig D. Allen, Jemez Mountains Field Station; Thomas W. Swetnam, University of Arizona; Nate G. McDowell, Los Alamos National Laboratory
10:30 AM
 Uncertainty and sensitivity analysis of process-based tree mortality models
Chonggang Xu, Los Alamos National Laboratory; Henry D. Adams, Los Alamos National Laboratory; Rosie A. Fisher, National Center for Atmospheric Research; Nate G. McDowell, Los Alamos National Laboratory
10:50 AM
 Current and future effects of drought, fire and mitigation options on Pacific Northwest forests
Beverly E. Law, Oregon State University; Tara W. Hudiburg, University of Illinois - UC; Sebastiaan Luyssaert, University of Antwerp; Nicholas Coops, University of British Columbia
11:10 AM
 Trees maintain broad hydraulic safety margins in their trunks during drought in a temperate forest
Aaron B. Berdanier, Duke University; James S. Clark, Duke University; Chelcy Ford Miniat, USDA Forest Service Southern Research Station; James Vose, USDA Forest Service Southern Research Station