Will changes in phenology track climate change? A study of growth initiation timing in coast Douglas-fir

Global Change Biology
By: , and 

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Abstract

Under climate change, the reduction of frost risk, onset of warm temperatures and depletion of soil moisture are all likely to occur earlier in the year in many temperate regions. The resilience of tree species will depend on their ability to track these changes in climate with shifts in phenology that lead to earlier growth initiation in the spring. Exposure to warm temperatures (“forcing”) typically triggers growth initiation, but many trees also require exposure to cool temperatures (“chilling”) while dormant to readily initiate growth in the spring. If warming increases forcing and decreases chilling, climate change could maintain, advance or delay growth initiation phenology relative to the onset of favorable conditions. We modeled the timing of height- and diameter-growth initiation in coast Douglas-fir (an ecologically and economically vital tree in western North America) to determine whether changes in phenology are likely to track changes in climate using data from field-based and controlled-environment studies, which included conditions warmer than those currently experienced in the tree's range. For high latitude and elevation portions of the tree's range, our models predicted that warming will lead to earlier growth initiation and allow trees to track changes in the onset of the warm but still moist conditions that favor growth, generally without substantially greater exposure to frost. In contrast, towards lower latitude and elevation range limits, the models predicted that warming will lead to delayed growth initiation relative to changes in climate due to reduced chilling, with trees failing to capture favorable conditions in the earlier parts of the spring. This maladaptive response to climate change was more prevalent for diameter-growth initiation than height-growth initiation. The decoupling of growth initiation with the onset of favorable climatic conditions could reduce the resilience of coast Douglas-fir to climate change at the warm edges of its distribution.

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Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Will changes in phenology track climate change? A study of growth initiation timing in coast Douglas-fir
Series title Global Change Biology
DOI 10.1111/gcb.13328
Volume 22
Issue 11
Year Published 2016
Language English
Publisher Blackwell Science
Contributing office(s) Northern Prairie Wildlife Research Center
Description 12 p.
First page 3712
Last page 3723
Country United States
State California, Oregon, Washington
Online Only (Y/N) N
Additional Online Files (Y/N) N