新疆荒漠草地生物量估算及影响因素研究

为探究新疆荒漠草地生物量反演模型及其影响因子，基于Terra/MODIS，NOAA CDR NDVI，SPOT/VGT等遥感产品数据及草地地上生物量实测数据，构建研究区荒漠草地地上生物量植被指数反演模型，分析新疆荒漠草地地上生物量时空分布规律，运用趋势分析法和相关性等方法，揭示了生物量演变趋势与气温、降水的关系。结果表明：建立的不同遥感数据源生物量模型中，指数函数反演模型精度最高，决定系数和估算精度分别为0.66和70.93%；基于2000—2019年归一化植被指数(Normalized difference vegetation index，NDVI)变化趋势发现，新疆荒漠草地以稳定和改善为主；研究区2000—2019年间荒漠草地地上生物量空间分布格局整体表现为北高南低的趋势，20年间荒漠草地平均地上生物量为38.92 g·m^-2；2000—2019年气温与降水均上升，年平均升温率和降水率达到了0.32℃·(10 a)^-1和2.18 mm·(10 a)^-1，50%以上的地区荒漠草地与气温、降水呈正相关关系，生物量与降水的相关性优于气温。研究结果可为新疆草地保护和改善、生态环境建设提供科学依据和技术支持。

Study on Biomass Estimation and Influencing Factors of Desert Grassland in Xinjiang

To explore the biomass inversion model and its influencing factors of desert grassland in Xinjiang,based on the remote sensing product data such as Terra/MODIS,NOAA CDR NDVI,SPOT/VGT,and the measured data of aboveground biomass of grassland,the aboveground biomass vegetation index inversion model of desert grassland in the study area was constructed,the temporal and spatial distribution law of aboveground biomass of desert grassland in Xinjiang was analyzed,and the trend analysis method and correlation method were used. The relationship between biomass evolution trend and temperature and precipitation was revealed. The results showed that:Among the biomass models established from different remote sensing data sources,the accuracy of the exponential function inversion model was the highest,and the determination coefficient and estimation accuracy were 0.66 and 70.93%,respectively;Based on the changing trend of NDVI from 2000 to 2019,it is found that the desert grassland in Xinjiang is mainly stable and improved;The spatial distribution pattern of aboveground biomass of desert grassland in the study area from 2000 to 2019 showed a trend of high in the north and low in the south. The average aboveground biomass of desert grassland in the past 20 years was 38.92 g·m^-2;From 2000 to 2019,both temperature and precipitation increased,and the annual average temperature rise rate and precipitation rate reached 0.32℃·(10 a)^-1 and 2.18 mm·(10 a)^-1. More than 50% of desert grassland had a positive correlation with temperature and precipitation,and the correlation between biomass and precipitation was better than that of temperature. The results can provide scientific basis and technical support for grassland protection and improvement and ecological environment construction in Xinjiang.