基于遥感指数的草原火后植被恢复研究

草原火是草原生态系统重要的干扰因子，严重影响着系统的结构与功能。基于遥感数据，以2015年“4·16”特大草原火灾为例，利用ENVI和ArcGIS等软件，分别对NDVI和GPP指数及火烧严重度下的植被恢复过程进行定量分析。结果表明，基于NDVI和GPP指数的火后植被恢复过程表现相似，不同年份植被恢复情况存在一定差异。火灾发生当年（2015年）火烧迹地植被恢复状况高于未发生火灾区域，而在火后第1年（2016年）却又稍低于未发生火灾区域，直到火后第2年（2017年），火烧迹地植被基本恢复到火前状态。同时，不同火烧严重度下的植被恢复过程在存在明显差异。草原火灾发生后当年（2015年），中强度火烧下植被恢复最好，其次是轻度，重度表现最差。草原火烧严重度对植被恢复的影响，主要表现在火后第1个植被生长季。在之后的年份里，由于草原更新能力强大，不同火烧严重度对草原植被的影响不明显。本研究可丰富草原火灾及火烧迹地植被恢复等相关研究成果，同时为草原火灾管理和草原生态系统的可持续发展提供科学依据。

Vegetation Regeneration After Grassland Fire Based on Remote Sensing Index

Grassland fire is a key disturbance factor in natural ecosystems that greatly influences ecosystem patterns and processes.Based on the remote sensing data of from a single burned area,the process of vegetation regeneration under different indices and different fire severities was analyzed quantitatively by the software of NDVI and GPP.The results of the vegetation regeneration process based on NDVI and GPP were similar,and there was a certain difference in vegetation regeneration among different years.In 2015,the vegetation recovery in the burned area was higher than that in the non-fire area,but it was slightly lower than that in the non-fire area in 2016.Until 2017,the vegetation in the burned area completely recovered to the pre fire state.The process of vegetation restoration under different fire severities was significant different in different years.In the first year after the occurrence of grassland fire,the restoration of vegetation was the best in moderate severity fire,followed by low severity,and high severity performed worst.The effect of grassland fire severity on vegetation recovery appeared mainly in the first growing season of vegetation after the fire occurrence.In the following years,the impact of the severity was nonexistent because of the strong capacity of grassland regeneration.The research results in this paper can enrich the research cases of grassland fire and vegetation regeneration,and provides scientific basis for the management of grassland fire behavior and the sustainable development of grassland ecosystem.