【摘要】 利用MOD13Q1数据和CASA模型计算内蒙古锡林郭勒盟地区2006-2015年间的植被净初级生产力(net primary productivity,NPP),并分析NPP时空变化趋势以及其与气象、牧畜量等因素之间的关系。研究表明,1)在时间分布上,锡盟地区10年内NPP呈增长趋势,平均增幅达到4.56gC·(m2·a)-1。中部地区NPP波动情况最为明显,变异系数在0.3以上,为生态敏感区。在空间分布上,NPP取值范围在0～750gC·(m2·a)-1,与地域植被类型、水热条件分布有关,表现为东部草甸草原>中部典型草原>西部荒漠草原。2)降水为该地NPP的决定性要素,其中达到强正相关的像元数目比有83.8%,且6、7月份降水对该地后期NPP影响显著。温度因子和NPP呈负相关关系,尤其是累积最高温度这一影响因子,但温度影响无显著滞后效应。3)牧畜量和NPP之间并不显著相关,说明并不是简单的牧畜量增高NPP就会下降,还应考虑牲畜排泄物对土壤有机质的改良,及啃食方式对植株遗传等多因素的影响。更多还原

【Abstract】 We calculated vegetation net primary productivity(NPP)in Xilingol league from 2006 to 2015,by using MOD13 Q1 and the Carnegie-Ames-Stanford Approach(CASA)model and analyzed NPP changes and contributing factors,such as meteorology and livestock.Results show that from 2006 to 2015,NPP increased by an average of 4.56 gC·(m2·a)-1.The fluctuation of NPP in the central region was the most obvious and the CV was more than 0.3,indicating that this area is sensitive.In terms of spatial distribution,NPP values ranged from 0 to 750 gC·(m2·a)-1,and variation was related to regional vegetation type and hydrothermal conditions.The NPP of the eastern meadow steppe was larger than that of central region grasslands,and the NPP of central region grasslands was larger than that of western desert grasslands.Precipitation was the determining factor for NPP in Xilingol League area,and the number of pixels with strong positive correlation level was 83.8%.Precipitation in June and July had a significant effect on NPP in the later period.Temperature was negatively correlated with NPP,and this was particularly true for the cumulative maximum temperature.No significant lag effect was detected for temperature.The correlation between NPP and livestock was not significant,indicating a misunderstanding that as the livestock increased,NPP will decrease.Therefore,we should also consider other factors,such as plant genetic change may be affected by eating patterns and soil improvement from livestock feces.更多还原