Tham khảo tài liệu 'global warming part 13', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | Section 5 11 Simulating Alpine Tundra Vegetation Dynamics in Response to Global Warming in China Yanqing A. Zhang1 Minghua Song2 and Jeffery M. Welker3 Department of Geography and School of Computing Science Simon Fraser University BC 2Institute of Geographic Sciences and Natural Resources Research the Chinese Academy of Sciences Beijing Environment and Natural Resources Institute University of Alaska Anchorage AK Canada . China 3USA 1. Introduction Global temperatures are increasing due to the effects of greenhouse gases emission. It is projected that climate changes will have profound biological effects including the changes in species distributions as well as vegetation patterns Walther et al. 2002 Klanderud Birks 2003 Pauli et al. 2003 Tape et al. 2006 . Many results from observations and experiments Parmesan 1996 Molau Alatalo 1998 Parmesan et al. 1999 Welker et al. 2000 2005 Schimel et al. 2004 Sullivan Welker 2005 and simulation studies Cramer Leemans 1991 Harras Prentice 2003 have depicted alterations in C and N cycling trace gas exchanges and shifts in the distribution of vegetation boundary and the mixture of shrubs and grasses. The Tibetan Plateau covers approximately million km2 with an average altitude of more than 4000 m dominated by alpine tundra Zheng 2000 . Alpine tundra vegetation is predicted to be one of the most sensitive terrestrial ecosystems to changing climate Korner 1992 Grabherr et al. 1994 Chapin et al. 1992 2000 . This type of ecosystem is composed of slow-glowing plants and are dominated by the soils which can be concentrated with high organic matter near surface soil that undergo frost heave and cryoturbation Billings 1987 Xia 1988 . Both plant growth and possible organic matter decomposition are predicted to increase under warmer climates which may cause alpine ecosystem carbon flux and energy flow changes Chapin et al. 1997 Kato et al. 2006 . Simultaneously warmer weather may increase plant growth and primary production .
