阿勒泰地区的草地退化严重阻碍了当地经济的可持续发展和畜牧业的稳定运行,如今受到了广泛的关注.而气候变化和人类活动被认为是草原退化的主要诱因,定量评估气候变化和人类活动对草地变化的相对作用,对于探究草地退化机制和控制草地退化具有重要意义.本文采用Carnegie-Ames-Stanford Approach和Thornthwaite memorial模型,模拟了2000-2019年阿勒泰地区的实际(NPPA)和潜在净初级生产力(NPPP),并采用两者之差来反映人类活动对草地净初级生产力的相对作用(NPPH).在此基础上,我们利用皮尔逊相关系数验证了模拟NPP的可行性,探究阿勒泰地区草地净初级生产力的时空变化,并构建综合情景以定量评估气候变化和人类活动对草地变化的相对作用.结果表明:(1)本文模拟的NPPA与MOD17A3数据集在空间分布上具有高度一致性;(2)NPPA增加的地区占总面积的70.53％,而NPPA减少的地区则为总面积的29.47％.研究期间,NPPA呈现出轻微的增加趋势(0.83 g C m-2 yr-1),而NPPP和NPPH则呈现出下降趋势(-1.31和-2.15 g C m-2 yr-1);(3)人类活动在草地恢复过程中起到了关键作用,人类活动促进了66.98％的区域发生恢复.气候变化则是导致草原退化的主要原因,导致55.70％的草地退化.这些结果可以揭示气候变化和人类活动所引起的草地变化机制,并进一步应用于制定阿勒泰地区防治荒漠化的有效措施.
Quantitative Assessment of the Effects of Climate Change and Human Activities on Grassland NPP in Altay Prefecture
Grassland degradation in Altay Prefecture is of considerable concern as it is a threat that hinders the sustainable development of the local economy and the stable operation of the livestock industry. Quantitative as-sessment of the relative contributions of climate change and human activities, which are considered as the domi-nant triggers of grassland degradation, to grassland variation is crucial for understanding the grassland degradation mechanism and mitigating the degraded grassland in Altay Prefecture. In this paper, the Carnegie-Ames-Stanford Approach model and the Thornthwaite memorial model were adopted to simulate the actual net primary productivity (NPPA) and potential net primary productivity (NPPP) in the Altay Prefecture from 2000 to 2019. Meanwhile, the difference between potential NPP and actual NPP was employed to reflect the effects of human activities (NPPH) on the grassland. On this basis, we validated the viability of the simulated NPP using the Pearson correlation coeffi-cient, investigated the spatiotemporal variability of grassland productivity, and established comprehensive scenar-ios to quantitatively assess the relative roles of climate change and human activities on grassland in Altay prefec-ture. The results indicate three main points. (1) The simulatedNPPA was highly consistent with the MOD17A3 da-taset in spatial distribution. (2) Regions with an increasedNPPA accounted for 70.53％ of the total grassland, whereas 29.47％ of the total grassland area experienced a decrease. At the temporal scale, theNPPA presented a slightly increasing trend (0.83 g C m-2 yr-1) over the study period, while the trends ofNPPP andNPPH were reduced (-1.31 and -2.15 g C m-2 yr-1). (3) Compared with climate change, human activities played a key role in the pro-cess of grassland restoration, as 66.98％ of restored grassland resulted from it. In contrast, inter-annual climate change is the primary cause of grassland degradation, as it influenced 55.70％ of degraded grassland. These re-sults could shed light on the mechanisms of grassland variation caused by climate change and human activities, and they can be applied to further develop efficient measures to combat desertification in Altay Prefecture.
NETL
NSTL
万方数据
维普
