| Title: | Cross-scale interaction of host tree size and climatic water deficit governs bark beetle-induced tree mortality |
| Author(s): | Koontz MJ; Latimer AM; Mortenson LA; Fettig CJ; North MP; |
| Address: | "Graduate Group in Ecology, University of California, Davis, CA, USA. michael.koontz@colorado.edu. Department of Plant Sciences, University of California, Davis, CA, USA. michael.koontz@colorado.edu. Earth Lab, University of Colorado-Boulder, Boulder, CO, USA. michael.koontz@colorado.edu. Graduate Group in Ecology, University of California, Davis, CA, USA. Department of Plant Sciences, University of California, Davis, CA, USA. USDA Forest Service, Pacific Southwest Research Station, Placerville, CA, USA. USDA Forest Service, Pacific Southwest Research Station, Davis, CA, USA. USDA Forest Service, Pacific Southwest Research Station, Mammoth Lakes, CA, USA" |
| DOI: | 10.1038/s41467-020-20455-y |
| ISSN/ISBN: | 2041-1723 (Electronic) 2041-1723 (Linking) |
| Abstract: | "The recent Californian hot drought (2012-2016) precipitated unprecedented ponderosa pine (Pinus ponderosa) mortality, largely attributable to the western pine beetle (Dendroctonus brevicomis; WPB). Broad-scale climate conditions can directly shape tree mortality patterns, but mortality rates respond non-linearly to climate when local-scale forest characteristics influence the behavior of tree-killing bark beetles (e.g., WPB). To test for these cross-scale interactions, we conduct aerial drone surveys at 32 sites along a gradient of climatic water deficit (CWD) spanning 350 km of latitude and 1000 m of elevation in WPB-impacted Sierra Nevada forests. We map, measure, and classify over 450,000 trees within 9 km(2), validating measurements with coincident field plots. We find greater size, proportion, and density of ponderosa pine (the WPB host) increase host mortality rates, as does greater CWD. Critically, we find a CWD/host size interaction such that larger trees amplify host mortality rates in hot/dry sites. Management strategies for climate change adaptation should consider how bark beetle disturbances can depend on cross-scale interactions, which challenge our ability to predict and understand patterns of tree mortality" |
| Keywords: | Animals California *Droughts Ecological Parameter Monitoring/statistics & numerical data Host-Parasite Interactions/physiology Pheromones/metabolism Pinus ponderosa/*parasitology/physiology Plant Bark/parasitology Plant Diseases/*parasitology Plant Disper; |
| Notes: | "MedlineKoontz, Michael J Latimer, Andrew M Mortenson, Leif A Fettig, Christopher J North, Malcolm P eng Research Support, U.S. Gov't, Non-P.H.S. England 2021/01/10 Nat Commun. 2021 Jan 8; 12(1):129. doi: 10.1038/s41467-020-20455-y" |
