Significant Siberian Vegetation Change is Inevitably Brought on by the Changing Climate

Abstract

The redistribution of terrestrial ecosystems and individual species is predicted to be profound under Global Climate Model simulations. We modeled the progression of potential vegetation and forest types in Siberia by the end of the twenty-first century by coupling large-scale bioclimatic models of vegetation zones and major conifer species with climatic variables and permafrost using the B1 and A2 Hadley Centre HadCM3 climate change scenarios. In the projected warmer and dryer climate, Siberian taiga forests are predicted to dramatically decrease and shift to the northeast, and forest–steppe, steppe, and novel temperate broadleaf forests are predicted to dominate most of Siberia by 2090. The permafrost should not retreat sufficiently to provide favorable habitats for dark (Pinus sibiric, Abies sibirica, and Picea obovata) taiga, and the permafrost-tolerant L. dahurica taiga should remain the dominant forest type in many current permafrost-lain areas. Water stress and fire-tolerant tree species (Pinus sylvestris and Larix spp.) should have an increased advantage over moisture-loving tree species (P. sibirica, A. sibirica, and P. obovata) in a new climate. Accumulated surface fuel loads due to increased tree mortality from drought, insects, and other factors, especially at the southern forest border and in the Siberian interior (Yakutia), together with an increase in severe fire weather, should also lead to increases in large, high-severity fires that are expected to facilitate vegetation progression toward a new equilibrium with the climate. Adaptation of the forest types and tree species to climate change in the south may be based on the genetic means of individual species and human willingness to aid migration, perhaps by seeding. Additionally, useful and viable crops could be established in agricultural lands instead of failing forests.