Widespread severe wildfires under climate change lead to increased forest homogeneity in dry mixed‐conifer forests

Ecosphere

Matthew D. Hurteau¹  Robert M. Scheller²  Melissa S. Lucash³  Brooke A. Cassell⁴  E. Louise Loudermilk⁵ 

[1] Department of Biology University of New Mexico Albuquerque New Mexico USA;Department of Forestry and Environmental Resources North Carolina State University Raleigh North Carolina USA;Department of Geography Portland State University Portland Oregon USA;Environmental Science and Management Department Portland State University Portland Oregon USA;Southern Research Station Center for Forest Disturbance Science USDA Forest Service Athens Georgia USA;

关键词: central Oregon, USA;    climate change;    dry mixed‐conifer forest;    forest change;    forest dynamics;    forest homogenization;   

DOI  :  10.1002/ecs2.2934

来源: DOAJ

【 摘 要 】

Abstract Climate warming in the western United States is causing changes to the wildfire regime in mixed‐conifer forests. Rising temperatures, longer fire seasons, increased drought, as well as fire suppression and changes in land use, have led to greater and more severe wildfire activity, all contributing to altered forest composition over the past century. To understand future interactions among climate, wildfire, and vegetation in a fire‐prone landscape in the southern Blue Mountains of central Oregon, we used a spatially explicit forest landscape model, LANDIS‐II, to simulate forest and fire dynamics under current management practices and two projected climate scenarios. The results suggest that wildfires will become more frequent, more extensive, and more severe under projected climate than contemporary climate. Furthermore, projected climate change generated a 20% increase in the number of extreme fire years (years with at least 40,000 ha burned). This caused large shifts in tree species composition, characterized by a decline in the sub‐alpine species (Abies lasiocarpa, Picea engelmannii, Pinus albicaulis) and increases in lower‐elevation species (Pinus ponderosa, Abies grandis), resulting in forest homogenization across the elevational gradient. This modeling study suggests that climate‐driven increases in fire activity and severity will make high‐elevation species vulnerable to decline and will reduce landscape heterogeneity. These results underscore the need for forest managers to actively consider climate change, altered fire regimes, and projected declines in sub‐alpine species in their long‐term management plans.

【 授权许可】

Unknown