近30年来梵净山植被覆盖时空变化及影响因素分析

梵净山以生物多样性和生态过程的独特优势入选世界自然遗产提名地，为揭示其植被覆盖空间分布与环境因子的相关性及变化规律，选取1990-2016年3个时期Landsat TM/ETM/OLI遥感影像提取植被覆盖度和土地利用数据，分析了梵净山植被覆盖度时空变化特征。结果表明:（1）近30年间，植被覆盖度呈"减少-增加"变化，缓冲区植被覆盖度变化敏感度高于提名地；（2）地形因子在水热条件方面不同程度上影响各等级植被覆盖度的空间分布，低山（<900 m）、低中山（900~1 600 m）植被覆盖度高且面积占比较大，斜坡、陡坡、急坡的植被覆盖度占较大比重，分别为33.33%，28.48%，12.18%，阳坡、半阳坡的植被覆盖度高于阴坡和半阴坡且差异性明显；（3）梵净山植被覆盖度变化受人类活动影响，导致地表覆盖改变而使植被覆盖度呈现典型碎斑状和带状的空间特征，缓冲区城镇化发展对生态环境的压力越来越大，提名地的旅游设施建设导致植被覆盖减少日趋明显。

Analysis on the Spatiotemporal Change and Influence Factors of Vegetation Cover in Fanjingshan Mountain over the Last 30 Years

Fanjingshan National Nature Reserve was selected as a nominated World Natural Heritage for its unique advantages in biodiversity and ecological process. To reveal the correlation between the spatial distribution of vegetation coverage and environment factors and the variation of the former, Landsat TM/ETM/OLI remote sensing images in 1990, 2002 and 2016 were selected to extract vegetation coverage and land use data and analyze the temporal and spatial variation characteristics of vegetation caverage in Fanjingshan. The results showed that:(1) over the past three decades, vegetation coverage decreased first and then increased, and the sensitivity of vegetation coverage change in the buffer zone was higher than that in the nominated property; (2) the terrain factor influenced the spatial distribution of each grade vegetation coverage in water and heat conditions at different degrees; the vegetation coverage in low mountain (< 900 m) and mid-low mountain (900~1 600 m) was high, which accounted for a larger proportion of the area; the vegetation coverage in slope, abrupt slope and steep slope accounted for 33.33%, 28.48% and 12.18%, respectively; the vegetation coverage in sunny slope and semi sunny slope was higher than that in shady slope and semi shady slope, and the difference was obvious; (3) with the gradual transformation of surface landscape caused by anthropogenic activities, the vegetation coverage change appeared blocky and striped spatial agglomeration; the urbanization in the buffer zone had brought increasing pressure to ecological environment; the construction of tourist facilities in the nominated property had led to the decreasing trend of vegetation coverage.