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Interactive climate factors restrict future increases in spring productivity of temperate and boreal trees

Zohner, Constantin M. ; Mo, Lidong ; Pugh, Thomas A.M. LU ; Bastin, Jean Francois and Crowther, Thomas W. (2020) In Global Change Biology 26(7). p.4042-4055
Abstract

Climate warming is currently advancing spring leaf-out of temperate and boreal trees, enhancing net primary productivity (NPP) of forests. However, it remains unclear whether this trend will continue, preventing for accurate projections of ecosystem functioning and climate feedbacks. Several ecophysiological mechanisms have been proposed to regulate the timing of leaf emergence in response to changing environmental cues, but the relative importance of those mechanisms remains unclear. Here, we use 727,401 direct phenological observations of common European forest trees to examine the dominant controls on leaf-out. Using the emerging mechanisms, we forecast future trajectories of spring arrival and evaluate the consequences for forest... (More)

Climate warming is currently advancing spring leaf-out of temperate and boreal trees, enhancing net primary productivity (NPP) of forests. However, it remains unclear whether this trend will continue, preventing for accurate projections of ecosystem functioning and climate feedbacks. Several ecophysiological mechanisms have been proposed to regulate the timing of leaf emergence in response to changing environmental cues, but the relative importance of those mechanisms remains unclear. Here, we use 727,401 direct phenological observations of common European forest trees to examine the dominant controls on leaf-out. Using the emerging mechanisms, we forecast future trajectories of spring arrival and evaluate the consequences for forest carbon dynamics. By representing hypothesized relationships with autumn temperature, winter chilling, and the timing of spring onset, we accurately predicted reductions in the advance of leaf-out. There was a strong consensus between our empirical model and existing process-based models, revealing that the advance in leaf-out will not exceed 2 weeks over the rest of the century. We further estimate that, under a ‘business-as-usual’ climate scenario, earlier spring arrival will enhance NPP of temperate and boreal forests by ~0.2 Gt per year at the end of the century. In contrast, previous estimates based on a simple degree-day model range around 0.8 Gt. As such, the expected NPP is drastically reduced in our updated model relative to previous estimates—by a total of ~25 Gt over the rest of the century. These findings reveal important environmental constraints on the productivity of broad-leaved deciduous trees and highlight that shifting spring phenology is unlikely to slow the rate of warming by offsetting anthropogenic carbon emissions.

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author
; ; ; and
publishing date
type
Contribution to journal
publication status
published
subject
keywords
carbon cycle, climate change, phenology, spring leaf-out, temperate forests, terrestrial carbon sink
in
Global Change Biology
volume
26
issue
7
pages
14 pages
publisher
Wiley-Blackwell
external identifiers
  • scopus:85084234389
  • pmid:32347650
ISSN
1354-1013
DOI
10.1111/gcb.15098
language
English
LU publication?
no
id
6d047e6c-d6d3-43d4-83b2-e3a1f432d859
date added to LUP
2020-11-19 22:04:45
date last changed
2021-04-06 05:39:55
@article{6d047e6c-d6d3-43d4-83b2-e3a1f432d859,
  abstract     = {<p>Climate warming is currently advancing spring leaf-out of temperate and boreal trees, enhancing net primary productivity (NPP) of forests. However, it remains unclear whether this trend will continue, preventing for accurate projections of ecosystem functioning and climate feedbacks. Several ecophysiological mechanisms have been proposed to regulate the timing of leaf emergence in response to changing environmental cues, but the relative importance of those mechanisms remains unclear. Here, we use 727,401 direct phenological observations of common European forest trees to examine the dominant controls on leaf-out. Using the emerging mechanisms, we forecast future trajectories of spring arrival and evaluate the consequences for forest carbon dynamics. By representing hypothesized relationships with autumn temperature, winter chilling, and the timing of spring onset, we accurately predicted reductions in the advance of leaf-out. There was a strong consensus between our empirical model and existing process-based models, revealing that the advance in leaf-out will not exceed 2 weeks over the rest of the century. We further estimate that, under a ‘business-as-usual’ climate scenario, earlier spring arrival will enhance NPP of temperate and boreal forests by ~0.2 Gt per year at the end of the century. In contrast, previous estimates based on a simple degree-day model range around 0.8 Gt. As such, the expected NPP is drastically reduced in our updated model relative to previous estimates—by a total of ~25 Gt over the rest of the century. These findings reveal important environmental constraints on the productivity of broad-leaved deciduous trees and highlight that shifting spring phenology is unlikely to slow the rate of warming by offsetting anthropogenic carbon emissions.</p>},
  author       = {Zohner, Constantin M. and Mo, Lidong and Pugh, Thomas A.M. and Bastin, Jean Francois and Crowther, Thomas W.},
  issn         = {1354-1013},
  language     = {eng},
  month        = {07},
  number       = {7},
  pages        = {4042--4055},
  publisher    = {Wiley-Blackwell},
  series       = {Global Change Biology},
  title        = {Interactive climate factors restrict future increases in spring productivity of temperate and boreal trees},
  url          = {http://dx.doi.org/10.1111/gcb.15098},
  doi          = {10.1111/gcb.15098},
  volume       = {26},
  year         = {2020},
}