气候变化下西南地区植物功能型地理分布响应

以中国西南地区(云南、贵州、四川和重庆)为研究区,基于中国植被图划分植物功能型,筛选影响各植物功能型分布的主导环境因子,进而通过最大熵模型结合未来气候情景(2050年)预测西南地区植物功能型地理分布。结果表明:(1)根据植物冠层特征(针叶/阔叶、常绿/落叶)及对水分和温度的需求,结合研究区实际植被数据,筛选得到15类植物功能型,包含6类乔木、6类灌木和3类草本功能型;(2)影响西南地区热带乔木分布的主导因子为最冷月最低温度和年降水量(贡献率达90.3%),亚热带植物功能型分布主要受到温度变化影响(贡献率达41.7%),温带植物功能型则受降水因子的影响最大(贡献率约40.1%),高寒草甸草和高寒常绿阔叶灌木主要受温度和海拔因子影响,高寒落叶阔叶灌木受降水因子影响大;(3)随CO₂排放量增加,未来西南各植物功能型分布呈现不同变化,其中,热带常绿阔叶乔木适宜区逐渐扩大;亚热带落叶木本类植物功能型的高适宜区面积2050年(RCP8.5)增至10.3%,呈东移趋势;亚热带常绿木本和草本类植物功能型适宜区广(占研究区总面积86.5%),未来气候下分布呈不规则波动;温带植物功能...

The geographical distribution response of plant functional types to climate change in southwestern China

Based on the Vegetation Map of China, the vegetation of southwest areas in China (including Yunnan, Guizhou, Sichuan Province, and Chongqing City) was classified into different plant functional types (PFTs), with the effective environmental factors of each PFTs determined. Combined with simulated future climate data (in 2050), the potential vegetation distribution of southwest areas in China was forecasted by Maximum Entropy Model. The results showed that:(1) According to the plant''s canopy characteristics (coniferous/broad-leaved, evergreen/deciduous), the demand for water and temperature, and the actual vegetation data, the vegetation of studied areas was classified into fifteen PFTs, including six types of trees, six types of shrubs and three types of herbal. (2) The dominant factors affecting the distribution of tropical trees in southwest China were the lowest temperature of the coldest month and the annual average precipitation (with a total contribution rate of 90.3%). The distribution of subtropical PFTs were mainly affected by changes in temperature (with a contribution rate of 41.7%). The distribution of temperate PFTs was mainly affected by precipitation (with a contribution rate of 40.1%). Alpine meadow grasses and Alpine evergreen broad-leaved shrubs were mainly affected by temperature and altitude, while the cold deciduous broad-leaved shrubs were mainly influenced by precipitation. (3) With an increase in CO₂ emissions, the distribution of PFTs in southwest China would change as following in the future. First, the suitable area of tropical evergreen broad-leaved trees would gradually expand. Second, areas of high suitability (RCP8.5) for the subtropical deciduous woody plants would increase to 10.3% in 2050, which tend to move eastward. Third, the subtropical evergreen woody and herbaceous plants would occupy a wide range of functionally suitable areas (i.e., 86.5% of the total study area) and display irregular fluctuations under the scenario of future climate. The suitable areas for the temperate plants (except the temperate shrubs) would decrease to 13.6% in 2050 (RCP8.5), while that for the temperate evergreen coniferous shrubs would increase. The highly suitable area would move to the west and the area would increase to 8.25 times of the present area in 2050 (RCP2.6). The suitable area of the alpine plants would decrease with the highly suitable area moving eastward.