2005-2014年南方农牧交错带净初级生产力时空分布特征

为了解我国南方农牧交错带内生态系统生产能力的变化程度，以2005—2014年MOD17A3H数据为数据源，利用简单差值法和一元线性回归分析法，对区内的植被年均NPP空间分布及变化趋势进行了分析。结果表明:（1）2005—2014年南方农牧交错带内植被NPP分布差异较大，整体呈南部高北部低。（2）年均植被NPP为389 gC/（m²·a），平均植被NPP变化范围在344～426 gC/（m²·a）之间。（3）2014年较2005年相比，南方农牧交错带植被NPP增加了106 gC/（m²·a）。但10年间植被NPP总体变化呈略微减少趋势，减少的地区面积占南方农牧交错区总面积的57%。（4）不同生态系统平均植被NPP均值表现为:森林生态系统 > 农田生态系统 > 灌丛生态系统 > 湿地生态系统 > 草地生态系统；不同生态系统植被NPP变化相似，呈波动略微减少变化。说明区域内生态系统变化波动较为明显，应对该区域生态系统给予更多的保护。

Temporal-Spatial Characteristics of the Vegetation Net Primary Production in the Farming-Pastoral Eco-Tone of Southern China During 2005-2014

In order to understand the change degree of ecosystem productivity in the farming-pastoral eco-tone southern China, the 2005—2014 annual vegetation NPP data from MOD17A3H dataset was used to analyze the inter-annual variation vegetation NPP and distribution of the average annual vegetation NPP by difference method and a linear regression. The research results indicated that: (1) significant differences in distribution of vegetation NPP presented a decrease trend from north to south, the average annual vegetation NPP was 389 gC/(m²·a), average annual vegetation NPP change ranged from 344 gC/(m²·a) to 426 gC/(m²·a)) in the farming-pastoral eco-tone of southern China during 2005—2014; (2) the average annual vegetation NPP increased by 106 gC/(m²·a) in 2014, the change presented a slight decrease trend, the areas with the decreased annual vegetation NPP accounted for 57% of the territory of the farming-pastoral eco-tone of southern China; (3) the average vegetation NPP for different ecosystems decrased in the sequence: that forest ecosystem > farmland ecosystem > scrub ecosystem > wetland Ecosystem > grassland Ecosystem; the change of vegetation NPP in different ecosystems was similar, and showed a slight decrease trend. It indicated that the fluctuation of ecosystem changes was more obvious and the protection of ecosystem should be strengthened.