Abstract
The responses of tree growth to recent climate warming may signal changes in the susceptibility of forest communities to compositional change and consequently impact a wide range of ecosystem processes and services. Previous research in the boreal forest has largely documented negative growth responses to climate in forest species and habitats characteristic of drier conditions, emphasizing the sensitivity of drier or warmer landscape positions to climate warming. In this study, we explored relationships between climate and tree-ring growth of black spruce, a dominant tree species typical of cool and moist habitats in the boreal forests of North America. We assessed how these responses Varied with stand characteristics and landscape position across four different regions in Alaska and Yukon Territory. Approximately half of the trees measured across regions and topographic gradients exhibited reduced radial growth in response to warm temperatures in the previous growing season and current spring, which we interpret as a signal of drought stress. Although we found considerable Variation in the growth responses of individual trees within sites, landscape position and stand characteristics were weak predictors of this Variability, explaining ≦12% of the Variation in any region. Our results indicate that future warming, particularly in spring, is likely to result in drought stress and a reduction of black spruce radial growth independent of region, landscape position, or stand characteristics. The occurrence of negative growth responses to temperature, even in cool and moist habitats, suggests that drought stress limitations may be more widespread in the northern boreal forest than previously anticipated, indicating broad sensitivity of ecosystem processes and services to climate change across a diverse range of habitat types.
Original language | English (US) |
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Article number | 064016 |
Journal | Environmental Research Letters |
Volume | 9 |
Issue number | 6 |
DOIs | |
State | Published - Jun 1 2014 |
Externally published | Yes |
Keywords
- black spruce
- boreal forest
- climate change
- dendroclimatology
- drought stress
- growth-climate responses
ASJC Scopus subject areas
- Renewable Energy, Sustainability and the Environment
- General Environmental Science
- Public Health, Environmental and Occupational Health