中国陆地净初级生产力的季节变化研究

Seasonal Change of Terrestrial Net Primary Productivity in China

了解不同季节陆地净初级生产力(NPP)的变化及与气候的相互关系以及在不同地类的差异对深刻理解我国陆地生态系统对全球气候变化的响应和陆地碳循环研究具有重要意义。本文使用1981～2000年间GLO～PEM模型模拟的我国陆地NPP数据和同期气温、降水以及土地利用数据.研究不同季节我国陆地植被NPP的变化。结果表明,在1981～2000年期间,四个季节的NPP都呈显著增加趋势,春季是NPP增加速率最快的季节,夏季是NPP增加量最大的季节。耕地在春、夏和秋季NPP增长和增长率最高,林地冬季NPP增长最多而水域冬季NPP增长率最高。夏季NPP增长最高的区域分布于我国东部的多数地区、内蒙古东部、四川盆地、贵州东部、藏南和新疆西部:夏季NPP降低最多的区域分布于在呼伦贝尔高原、鄂尔多斯高原、黄土高原、青藏高原东部和新疆西北部。

Study on seasonal change of terrestrial net primary productivity (NPP) and its relationship with climate as well as, its variations in different land-use types is to help understand the responses of Chinese terrestrial ecosystem to global climate change and is important to carbon cycle research. In this study, time series dataset of Chinese terrestrial NPP from GLO-PEM model and corresponding information on climate and land use were used to explore the seasonal trends of terrestrial NPP in China from 1981 to 2000. As the result, seasonal NPP in China showed a significant increase for all four seasons (spring, summer, autumn and winter) during the past 20 years. The spring NPP indicated the largest increase rate, while the summer NPP was with the largest increase in magnitude. Seasonal NPP dynamics were different in different land-use types. Croplands had the largest NPP increase and increase rate in spring, summer and autumn, and woodland had the largest NPP increase in winter, while water had the largest NPP increase rate in winter. The regions with the largest increase in summer NPP occurred in most parts of eastern China, eastern Inner-Mongolia, Sichuan Basin, eastern Guizhou, southern Xizang and western Xinjiang, while the areas with the largest decrease in summer NPP appeared mainly in Hulun Buir Plateau, Ordos Plateau, Loess Plateau, eastern Qinghai-Tibet Plateau and northwestern Xinjiang.