近20年气候变化对西南地区植被净初级生产力的影响

The Influence of Climate Change on Vegetation Net Primary Productivity in Southwestern China during Recent 20 Years Period

论文利用大气-植被相互作用模型(AVIM2)模拟了西南地区植被净初级生产力的空间分布格局和多年变化,分析了1981—2000年西南地区气候变化对森林、灌丛和草地净初级生产力的影响。研究表明,西南地区植被净初级生产力的空间分布与降水量呈显著正相关,与海拔高度呈负相关。从年际变化来看,西南地区总植被净初级生产力近20年略有上升。近一步分析表明,由于近20年西南地区自然植被分布区域降水量变化具有明显差异,从而使得不同类型植被对气候变化有不同响应特征。在森林分布广泛的地区,气温升高速率为0.037℃/年,降水量变化趋势不明显,模拟的森林植被净初级生产力没有明显变化趋势。灌丛和草地集中区域气温升高速率分别为0.040℃/年和0.034℃/年,年降水量有明显增加趋势,植被净初级生产力有上升趋势。

The climate change and its induced ecosystem change have gotten more and more attentions from scientists and societies.The past researches showed that the temperature and precipitation variations in southwestern mountainous area of China were different from those in the other parts of China.So the climate change and its impacts on ecosystem in southwestern China is still a question to be understood.In this study, the spatial distributions and interannual variations of net primary productivity（NPP）were simulated by the atmosphere-vegetation interaction model （AVIM2）in southwestern China.The responses of forests,shrub lands,grasslands and crop lands to temperature and precipitation change during 1980 to 2000 were discussed.The study indicates that the spatial distribution of vegetation NPP in southwestern China is positively correlated with the pattern of precipitation and negatively correlated with that of elevation.The total vegetation NPP of southwestern part increased in the 20 years period.More detailed analyses show that variation of plant function type＇s NPP are different due to precipitation in the areas where they are located varies.In forest area,where the mean temperature rise rate is 0.037℃ per year and the precipitation has no obvious trend,the simulated annual NPP does not show any increase or decrease trend.In shrub lands and grasslands area,where the temperature rise rate is 0.040℃ and 0.034℃ per year,individually, and the precipitations increased, both the simulated shrub and grass NPP show significant increase tendency.