中国东南部植被NPP的时空格局变化及其与气候的关系研究

基于2001~2010年MOD17A3年均NPP数据和气象站点气温、降水资料,利用GIS空间分析技术和数理统计方法研究中国东南部植被NPP的时空格局、动态变化及与气候要素的关系。结果表明,中国东南部植被年均NPP总体上呈现从南到北、由东至西逐渐减少的分布,不同植被类型的NPP存在明显差异,以常绿阔叶林最高,落叶针叶林最低。2001~2010年间,植被NPP整体上略有减少。空间上植被NPP在南部地区明显减少,而在北部地区明显增加。植被NPP与降水和气温的相关性均表现出明显的地域差异。

Spatial and Temporal Pattern of Vegetation NPP and Its Relationship with Climate in the Southeastern China

The interaction between vegetation and atmosphere is a research focus and hotspot in the field of earth science under the background of global change. Net primary productivity (NPP) has become a key link of biogeochemical cycle process of terrestrial ecosystems in the global and regional scale, which embodies the complex interaction between vegetation, soil and climate, and is strongly influenced by human activities and global environmental change. Therefore, it has important significance to know the spatial and temporal pattern, variation characteristic and the relationship between terrestrial NPP and climate factors, especially temperature and precipitation, in the evaluation of environment quality, estimation of the terrestrial carbon source/sink potentials, and the management and use of natural resources. Based on the average annual NPP data of MOD17A3 data and temperature and rainfall data from meteorological stations during 2001-2010, the temporal and spatial pattern and dynamic change of vegetation NPP in southeastern China and their relationship with climate elements were analyzed using GIS spatial analysis technology and mathematical statistics method. The results indicate that average annual vegetation NPP in southeastern China gradually decreased from the southern to the northern parts and from the eastern to the western parts as a whole. Different vegetation types had different average annual NPP, with evergreen broad-leaved forest had the highest average annual NPP and deciduous coniferous forest had the lowest NPP. In addition to deciduous coniferous forest, the NPP of high forest was significantly higher than that of low vegetation such as field crops and herbaceous plants. The average annual vegetation NPP reduced slightly as a whole in southeastern China during 2001-2010, and it increased rapidly during 2001-2004, after then it reduced gradually. Spatially, vegetation NPP decreased significantly in the southern regions, but increased significantly in the northern regions. In Jiangsu, southern Anhui, Zhejiang, Jiangxi, western Fujian, central and southern Hunan and northern Guangdong, vegetation NPP decreased at a rate of over 150 g/m² per year in carbon value, but in southwestern Shanxi, western and central Henan, northwestern Hubei and northwestern Anhui, vegetation NPP annual carbon value increased at a rate of over 150 g/m² per year in carbon value. The correlation between vegetation NPP and rainfall and temperature showed significant regional differences, with closer relationship between vegetation NPP and rainfall in northern regions, where precipitation increased in most areas in the past 10 years, and in the southern regions, where plum rains were removed northerly, and temperature increased in most of areas.