干旱胁迫下植物抗逆性大尺度遥感监测方法

目前干旱与植被关系的研究主要集中于气候因子与植被时空变化的相关性分析以及植被对气候变化的响应，能够适用于大尺度的植物抗逆性监测方法还较为欠缺。本文基于归一化植被指数（NDVI）、总初级生产力（GPP）、修正花青素含量指数（mACI）、短波红外水分胁迫指数（SIWSI）监测干旱胁迫下的植被变化，综合考虑植物抗逆过程，建立滞后时间、抗逆时差、响应程度与恢复能力4个植物抗逆性监测指标，构建了一种能够适用于大尺度的植物抗逆性综合监测方法。利用各省份作物抗逆性综合评分与绝收比例进行相关性分析，两者呈显著负相关。利用该方法对干旱胁迫下我国不同类型植被的抗逆性进行评估，结果表明：① 从全国整体水平来看，不同季节植物抗逆性差异较大，其中夏季植物抗逆性最弱，冬季最强。我国植物抗逆性空间异质性显著，春季植物抗逆性综合评分低于70分的区域主要位于山西、陕西北部，综合评分高于90分的区域主要集中在内蒙古东北部以及云南的南部地区； ② 不同类型植被的抗逆性有明显差异，夏季落叶针叶林抗逆性最强，类内差异最小，春秋两季草地抗逆性最强但抗逆性类内差异最大。本文提出的植物抗逆性综合监测方法有助于探索干旱胁迫下植物抗逆性规律，对帮助降低灾害风险具有借鉴意义。

Remote Sensing Monitoring Method for Plant Stress Resistance under Drought Stress on Large Scale

Current research on the relationship between drought and vegetation has focused on two aspects. One is the correlation analysis between climate factors and spatiotemporal variation of vegetation, and the other is the response of vegetation to climate change. Methods for large-scale plant stress resistance monitoring are still lacking. This study used Normalized Difference Vegetation Index (NDVI), Gross Primary Productivity (GPP), Modified Anthocyanin Content Index (mACI), and Shortwave Infrared Water Stress Index (SIWSI) to monitor vegetation changes under drought stress. A comprehensive monitoring method for plant stress resistance was constructed. This method comprehensively considered the stress resistance process of plants and established four indicators. Correlation analysis was carried out using the comprehensive score of crop stress resistance and the harvestless rate of each province. There was a negative relationship between crop stress resistance and harvestless rate. This method was applied to evaluate the resistance of different types of vegetation to drought stress in China. The results showed that: (1) Plant stress resistance varied greatly in different seasons. It was weakest in summer and strongest in winter. The spatial heterogeneity of plant stress resistance in China was significant. In spring, the regions with comprehensive scores lower than 70 were mainly located in Shanxi and northern Shaanxi. The regions with comprehensive scores higher than 90 were mainly concentrated in northeastern Inner Mongolia and the southern part of Yunnan; (2) There were obvious differences in the stress resistance of different types of vegetation. In summer, deciduous coniferous forest had the strongest stress resistance and the smallest intra-class differences. In spring and fall, grassland had the strongest stress resistance and the greatest intra-class differences. The comprehensive monitoring method of plant stress resistance is helpful to explore the law of plant stress resistance under drought stress, which provides references for helping reduce disaster risks.