Simulation of Boreal Treeline Migration in A Warming World
Abstract
The North American boreal region is warming at an accelerated rate compared to the rest of the globe, which will impact vegetation, soils, and the disturbance regime. Recent studies using modeling, remote sensing, and field data predict boreal range shifts, with contractions predicted in the southern margins as a result of drought and insect infestation, and expansions predicted in the northern margins as temperatures warm. While the climate suitability `envelope' for boreal tree species may be expanding northward with climate change, it is still unclear how fast migration may actually occur given constraints on seed rain, regeneration, and growth to reproductive age and size. We use an individual-based forest model (UVAFME) to simulate forest response to changing climate at the northern treeline in interior Alaska and to assess the potential for a northward treeline shift. UVAFME has been previously used in interior Alaska and comparisons with inventory data and other abiotic characteristics show good agreement with observations. UVAFME is updated for this study to simulate seed rain from a source grid cell to adjacent grid cells, dependent on the density of and distance to reproductively active trees. Model results predict a northward shift in the treeline, though the speed of this shift is sensitive to local-scale conditions as well as the parameters used for seed dispersal. These results have implications for changing biogeophysiology at the broader tundra-taiga ecotone, as increasing forest cover would alter energy and water fluxes, soil conditions, as well as the fire regime.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2020
- Bibcode:
- 2020AGUFMB100...01F
- Keywords:
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- 0414 Biogeochemical cycles;
- processes;
- and modeling;
- BIOGEOSCIENCES;
- 0428 Carbon cycling;
- BIOGEOSCIENCES;
- 0439 Ecosystems;
- structure and dynamics;
- BIOGEOSCIENCES;
- 0475 Permafrost;
- cryosphere;
- and high-latitude processes;
- BIOGEOSCIENCES