2000—2020年四川省泸沽湖湿地自然保护区陆地植被覆盖动态变化

Dynamic Changes of Terrestrial Vegetation Cover in Lugu Lake Wetland Nature Reserve, Sichuan Province from 2000 to 2020

[目的]探究四川省泸沽湖湿地自然保护区2000—2020年陆地植被覆盖度的时空变化规律,为保护区的建设和治理提供参考。[方法]选用四川泸沽湖湿地自然保护区2000—2020年植被生长旺盛月份(6—9月)的MODIS数据为数据源,结合像元二分法、Theil-SenMedian趋势分析法等相关分析法探究植被覆盖度时空变化特征及其对气候的响应。[结果](1)在时间变化上,四川省泸沽湖湿地自然保护区陆地植被覆盖度呈略微上升趋势,整体以0.09/10 a速率波动上升。(2)保护区植被覆盖度在空间分布上呈现湖区及其周边区域低,南北高的特征,呈现整体上升,局部下降的特点。(3)保护区气候(6—9月)趋向“暖干化”发展,植被覆盖度与气温和降水量以正相关为主,且受气温影响大于降水,其影响因素具有空间差异性。[结论] 2000—2020年,泸沽湖湿地自然保护区植被覆盖良好,植被覆盖度总体呈略微上升趋势,其中,气温是影响植被覆盖度的主要气候因子,同时地形、人类活动对保护区植被覆盖度均有一定的影响。

[Objective]The spatial-temporal variation of terrestrial vegetation coverage in Lugu Lake Wetland Nature Reserve in Sichuan Province during 2000—2020 was analyzed in order to provide a reference for the construction and management of the reserve.[Methods]MODIS data from June to September of 2000—2020 for the Lugu Lake Wetland Nature Reserve in Sichuan Province was the data source.Correlation analysis methods such as pixel dichotomy and Theil-SenMedian trend analysis were combined to determine the spatial-temporal variation characteristics of vegetation coverage and their response to climate.[Results]①The overall terrestrial vegetation coverage of Lugu Lake Wetland Nature Reserve in Sichuan Province slightly increased from^(2)000 to 2020,and increased at a rate of 0.09/10 yr.②Vegetation coverage of the protected area was low in the lake area and the surrounding areas,and higher in the north and south areas.The spatial variation of vegetation coverage of the protected area increased overall but decreased locally.③The climate of the reserve(from June to September)tended to be“warmer and drier”,and fractional vegetation coverage was mainly positively correlated with temperature and precipitation.The influence of temperature was greater than that of precipitation.The specific influencing factors had spatial differences.[Conclusion]From^(2)000 to 2020,the vegetation coverage of the Lugu Lake Wetland Nature Reserve in Sichuan Province was good,and the vegetation coverage slightly increased over time.Temperature was the main climate factor affecting vegetation coverage.Topography and human activities,meanwhile,had some effects on the vegetation coverage of the reserve to a certain extent.