【摘要】 应用2005年5~10月份EOS/MODIS资料,采用光能利用率估算方法,对中国西北荒漠绿洲区甘肃省安西县荒漠草原区的月净第一生产力、年净第一生产力进行估算,并结合地面观测,分析了不同牧草类型NPP的时间变化和空间分布特征。结果表明,安西县荒漠草原区2005年牧草生长期内NPP的变化基本是6、7月份最大,其它月份较小,5~6月份是牧草叶面积变化比较大的时期,也是NPP变化比较显著的时期;荒漠牧草对光的利用能力和对CO2同化能力有很大差异,白刺、红砂、黑果枸杞是荒漠草场净生产力相对比较大的牧草类型;荒漠牧草区年净第一生产力的空间分布有很大的差异,禁牧区牧草的年NPP相对非禁牧区的NPP较大,这一结论与地面观测结果相一致,NPP估算值平均误差为12.6%。更多还原

【Abstract】 By the estimation method of the efficiency for solar energy utilization,the monthly and annual grass net primary productivity(NPP) of the desert area in Anxi County of Gansu lying in desert oasis area of Northwest China are estimated with EOS/MODIS data collected in May～October 2005 and the temporal and spatial distributions of the net production rates of the different grasses are analyzed in combination with field observation.It is shown that in the desert area of Anxi County the grass NPP appeared the highest in June and July 2005 during growth season and lower in the other months during the growth season,and May～June are the period when the leaf area index greatly varies and the NPP significantly varies;the desert grasses greatly differ in solar energy utilization and carbon dioxide assimilation,and Nitraria tangutorum,Lycium ruthenicum and Reaumuria soongorica are the grasses with high NPP;In the desert area spatial distribution of the annual NPP varies greatly and the NPP in the grazing-prohibited area is higher than that in the grazing area,and this agrees with the result in the field observation.The average NPP error is 12.6% in the estimation.更多还原