File(s) not publicly available
Mortality predispositions of conifers across Western USA
journal contribution
posted on 2021-04-20, 03:42 authored by Wenzhi Wang, Nathanael Brooks-EnglishNathanael Brooks-English, Charlotte Grossiord, Arthur Gessler, Adrian J Das, Nathan L Stephenson, Christopher H Baisan, Craig D Allen, Nate G McDowellConifer mortality rates are increasing in western North America, but the physiological mechanisms underlying this trend are not well understood.
We examined tree-ring-based radial growth along with stable carbon (C) and oxygen (O) isotope composition (δ13C and δ18O, respectively) of dying and surviving conifers at eight old- growth forest sites across a strong moisture gradient in the western USA to retrospectively investigate mortality predispositions.
Compared with surviving trees, lower growth of dying trees was detected at least one decade before mortality at seven of the eight sites. Intrinsic water-use efficiency increased over time in both dying and surviving trees, with a weaker increase in dying trees at five of the eight sites.
C starvation was a strong correlate of conifer mortality based on a conceptual model incor- porating growth, δ13C, and δ18O. However, this approach does not capture processes that occur in the final months of survival. Ultimately, C starvation may lead to increased mortality vulnerability, but hydraulic failure or biotic attack may dominate the process during the end stages of mortality in these conifers.
History
Volume
229Issue
2Start Page
831End Page
844Number of Pages
14eISSN
1469-8137ISSN
0028-646XLocation
EnglandPublisher
WileyPublisher DOI
Language
enPeer Reviewed
- Yes
Open Access
- No
Acceptance Date
2020-08-03External Author Affiliations
US Geological Survey, University of Arizona, US Geological Survey, Pacific Northwest National Laboratory, USA; Swiss Federal Institute for Forest, Snow and Landscape WSL, SwitzerlandEra Eligible
- Yes