甘肃省季节性净初级生产力变化特征

Variation Characteristics of Seasonal Net Primary Productivity in Gansu Province

针对不同尺度视角下NPP时空差异及其影响因素的研究还比较匮乏的问题,以甘肃省为靶区,通过改进CASA模型估算了NPP的空间格局,并通过偏相关系数探讨NPP与气候因子的关系。甘肃省4季的NPP空间差异显著,变化强烈,呈现东南高西北低。以甘肃省为视角,降水量是夏季的主要控制气候因子,而气温是其他季节的主导气候因子。以不同生态区为视角,仅在夏季,季降水量是草原生态区、农业生态区和荒漠生态区的主要控制因子,其他主要控制因子均为季均温。春季,草原生态区对季均温存在时滞与累积效应;夏季,森林与农业生态区对季降水量和季均温存在时滞与累积效应;秋季,森林与草原生态区对季降水量和农业生态区对季均温都存在时滞与累积效应。

The study on time and space differences of NPP and how influence factors affects NPP is scarce at several different scales. Here we take Oansu province as the target, the spatial pattern of NPP in Gansu province and how climate factor affects NPP were discussed using an improved CASA model, and coefficient of partial correlation. There were significantly different and change for the seasonal NPP spatial distribution in Gansu province, reflecting that the variations were decreasing form the southeast with high values to northwest with low values. The summer was mainly influenced by the factor of precipitation,and the temperature was the main control factor in other seasons in the perspective of Oansu province. In the perspective of different ecological biomes, the grassland, agrieulture and desert biome were mainly influenced by the factor of seasonal precipitation in the summer only, and the seasonal temperature was the main control factor in other seasons. The grassland biome of seasonal temperature manifested the time lag and cumulative effect in spring. The forest and agriculture biome of climate factors （precipitation and temperature） manifested the time lag and cumulative effect in summer. Compared with the forest and grassland biome of seasonal precipitation,the agriculture biome of seasonal temperature also manifested the time lag and cumulative effect in autumn.