Temperature sensitivity of drought-induced tree mortality portends increased regional die-off under global-change-type drought

• DOI: 10.1073/pnas.0901438106
• Publication Date: 2009-04-14T00:45:48Z
• Authors: Henry D. Adams; Maite Guardiola-C...; Greg A. Barron-Ga...; Juan Camilo Villegas; David D. Breshears; Chris B. Zou; Peter A. Troch; Travis E. Huxman
• Keywords: Global Change

Large-scale biogeographical shifts in vegetation are predicted response to the altered precipitation and temperature regimes associated with global climate change. Vegetation have profound ecological impacts an important climate-ecosystem feedback through their alteration of carbon, water, energy exchanges land surface. Of particular concern is potential for warmer temperatures compound effects increasingly severe droughts by triggering widespread via woody plant mortality. The sensitivity tree mortality dependent on which 2 non-mutually-exclusive mechanisms predominates—temperature-sensitive carbon starvation a period protracted water stress or temperature-insensitive sudden hydraulic failure under extreme (cavitation). Here we show that experimentally induced (≈4 °C) shortened time drought-induced Pinus edulis (piñon pine) trees nearly third, temperature-dependent differences cumulative respiration costs implicating as primary mechanism Extrapolating this effect historic frequency deficit southwestern United States predicts 5-fold increase regional-scale die-off events species due alone. Projected increases drought changes from biotic agents (e.g., bark beetles) would further exacerbate Our results demonstrate exacerbated recent regional background rates. Because pervasive projected temperature, our portend extent die-off.