The predicted effects of climate change on local species distributions around Beijing, China

To assist conservationists and policymakers in managing and protecting forests in Beijing from the effects of climate change, this study predicts changes for 2012-2112 in habitable areas of three tree species-Betula platyphylla, Quercus palustris, Platycladus orientalis,plus other mixed broadleaf species-in Beijing using a classification and regression tree niche model under the International Panel on Climate Change's A2 and B2 emissions scenarios (SRES). The results show that climate change will increase annual average temperatures in the Beijing area by 2.0-4.7 degrees C, and annual precipitation by 4.7-8.5 mm, depending on the emissions scenario used. These changes result in shifts in the range of each of the species. New suitable areas for distributions ofB. platyphyllaandQ. palustriswill decrease in the future. The model points to significant shifts in the distributions of these species, withdrawing from their current ranges and pushing southward towards central Beijing. Most of the ranges decline during the initial 2012-2040 period before shifting southward and ending up larger overall at the end of the 88-year period. The mixed broadleaf forests expand their ranges significantly. TheP. orientalisforests, on the other hand, expand their range marginally. The results indicate that climate change and its effects will accelerate significantly in Beijing over the next 88 years. Water stress is likely to be a major limiting factor on the distribution of forests and the most important factor affecting migration of species into and out of existing nature reserves. There is a potential for the extinction of some species. Therefore, long-term vegetation monitoring and warning systems will be needed to protect local species from habitat loss and genetic swamping of native species by hybrids.