2000—2015年秦巴山区植被净初级生产力时空变化及其驱动因子

基于2000—2015年MOD17A3数据及各驱动因素数据,辅以地统计学理论,利用趋势分析、Hurst指数及相关分析等方法,剖析秦巴山区近16年植被净初级生产力(NPP)时空变化特征,研究气候变化、土壤类型、地形因子、植被类型及人类活动等对植被NPP的影响.结果表明: 秦巴山区植被NPP空间上呈西南高、东北低的分布格局;时间上,近16年呈西北增、东北减的变化特征,在未来呈北部持续性、南部反持续性的发展态势.秦巴山区植被NPP与降雨量和气温呈正相关;暗棕壤、黄壤、紫色土和水稻土4种土壤类型的NPP均值明显高于其他土壤类型;不同植被类型的NPP存在空间分布和变化趋势的差异;NPP的高值主要分布在坡度25°～50°、海拔500～1000 m 以及大于2500 m的区域内;人类活动对NPP具有双重扰动性,表现为正向促进,反向抑制.

Spatiotemporal variation of vegetation net primary productivity and its driving factors from 2000 to 2015 in Qinling-Daba Mountains,China.

We analyzed spatiotemporal changes in vegetation net primary productivity (NPP) in the Qinling-Daba Mountains based on MOD17A3 data and driving factor data from 2000 to 2015. We used trend analysis, Hurst index, and correlation analysis to examine the effects of climate change, soil type, topographic factors, vegetation type, and human activities on NPP. With respect to spatial variation, NPP was the highest in southwestern area and lowest in the northeast. The temporal trend over the 16-year period showed that NPP was increased in the northwest and decreased in the northeast. The projected trend of NPP was of continuity in northern area and anti-continuity in southern area of the Qinling-Daba Mountains. NPP was positively correlated with precipitation and temperature. NPP in areas with dark-brown earths, yellow earths, purplish soils and paddy soils were significantly higher than those with other soil types. The spatial distribution and trends of NPP differed among vegetation types. High NPP mainly occurred on slopes of 25° to 50° and altitudes of 500 to 1000 m or above 2500 m. Human activities had both positive and suppressive effects on NPP.