基于Landsat影像评估鸡足山火烧迹地近40年植被恢复动态  

Assessment of vegetation recovery dynamics over nearly 40 years in the Jizu Mountain burnt area based on Landsat imagery

作　　者：苏维翰 张楚然 邓云[1,4] 翟德利 张明达 李生发[2,3] 李逢昌 唐志忠 林露湘 SU Weihan;ZHANG Churan;DENG Yun;ZHAI Deli;ZHANG Mingda;LI Shengfa;LI Fengchang;TANG Zhizhong;LIN Luxiang(CAS Key Laboratory of Tropical Forest Ecology,Xishuangbanna Tropical Botanical Garden,Chinese Academy of Sciences,Mengla 666303,China;Dali forestry and grassland Bureau,Dali 671006,China;Yu Jin′an State-owned Forest Farm,Dali 671009,China;National Forest Ecosystem Research Station at Xishuangbanna,Mengla 666303,China;Yunnan Climate Center,Kunming 650034,China;University of Chinese Academy of Sciences,Beijing 100049,China)

机构地区：[1]中国科学院西双版纳热带植物园热带森林生态学重点实验室,勐腊666303 [2]大理市林业和草原局,大理671006 [3]大理市余金庵国有林场,大理671009 [4]云南西双版纳森林生态系统国家野外科学观测研究站,勐腊666303 [5]云南省气候中心,昆明650034 [6]中国科学院大学,北京100049

出　　处：《生态学报》2025年第3期1362-1378,共17页Acta Ecologica Sinica

基　　金：云南省重点研发计划(202303AC100009);云南省基础研究专项重大项目(202101BC070002);云南省基础研究专项(202301AT070356)。

摘　　要：大范围、高强度的森林火灾能够摧毁地表植被并重启群落演替进程,是影响滇中地区森林生态系统稳定的重要干扰因素之一,但当地这些火烧事件的干扰边界和随后的植被恢复动态目前仍缺乏足够的定量报道。以大理鸡足山亚热带半湿润常绿阔叶林分布区内1984年5月3日发生火灾的火烧迹地为主要研究对象,基于1986-2023年的Landsat多时序影像,尝试以差值归一化燃烧指数(difference Normalized Burn Ratio,dNBR)对当地历史火烧事件的火烈度边界进行定量划分,以地形因子和多重比较对不同火烈度区域间空间分布格局差异进行解释和分析;以植被覆盖度(Fractional Vegetation Cover,FVC)、归一化燃烧指数(Normalized Burn Ratio,NBR)和燃烧恢复率(Burn Recovery Ratio,BRR)等遥感植被指数时序变化和分段线性回归模型对火烧迹地上的植被恢复阶段进行定量区分,结合气温和降水等气候因子的时序变化对植被恢复过程中的重要时间拐点进行解释,并以林冠高度特征对火烧迹地目前的植被恢复程度进行评价。研究结果表明:当地1984年时的总过火面积应不小于1423.71 hm^(2),火烧迹地可划分为轻度、中低度、中高度和重度等四个火烈度(Fire severity)等级,面积比例分别为63.39%、30.73%、5.85%和0.03%,坡度较小则火烈度可能越高;轻度和中低度火烈度区可分为快速恢复(1986-1996年)和降速恢复阶段(1996年至今),中高度和重度火烈度区可分为快速恢复(1986-1990年)、降速恢复(1990-1996年)和稳定(1996年至今)阶段,但气候因子并未表现出类似的阶段性变化,遥感植被指数的时间动态更多与植被演替过程中的树种迭代过程有关;各火烈度区域内的林冠平均高度至今仍较对照区(26.4 m)偏低,林冠结构和森林地上生物量应仍处于恢复过程中。当地火烧迹地上的森林经过40年的恢复后应仍处于次生演替的前中期,亚热带半湿润常绿阔叶Extensive and high⁃intensity forest fires can destroy surface vegetation,restart community succession processes,and are among the significant disturbances affecting the stability of forest ecosystems in central Yunnan.However,there is a lack of sufficient quantitative reports on the disturbance boundaries of these fire events and the subsequent vegetation recovery dynamics in the area.This study focuses on the burnt area from the fire that occurred on May 3,1984,in the subtropical semi⁃humid evergreen broadleaf forest of Jizu Mountain,Dali.Based on Landsat multi⁃temporal images from 1986 to 2023,we attempt to quantitatively delineate the boundaries of fire severity for historical fire events using the difference Normalized Burn Ratio(dNBR).We also analyze and explain the spatial distribution pattern differences between areas of varying fire severity using topographic factors and multiple comparisons.The stages of vegetation recovery in the burnt area are quantitatively distinguished using remote sensing indices,including the Fractional Vegetation Cover(FVC),Normalized Burn Ratio(NBR),and Burn Recovery Ratio(BRR),in conjunction with time⁃series analysis and piecewise linear regression models.We examine time points in the vegetation recovery process by analyzing the temporal changes in climatic factors such as temperature and precipitation.Additionally,we assess the current degree of vegetation recovery degree in the burnt area using canopy height characteristics.The results indicate that the total burnt area in 1984 should be no less than 1423.71 hm^(2).The burnt area is divided into four fire severity levels:low,moderate⁃low,moderate⁃high,and high,with area proportions of 63.39%,30.73%,5.85%,and 0.03%,respectively.Analysis reveals that areas with gentler slopes tend to have higher fire severity.The low and moderate⁃low fire severity areas are categorized into rapid recovery(1986 to 1996)and decelerated recovery stages(1996 to present),while the moderate⁃high and high fire severity areas are divide

关 键 词：卫星遥感 多光谱 火烈度 火烧迹地 植被恢复 

分 类 号：S71[农业科学—林学]