{Reference Type}: Journal Article
{Title}: [Characteristics and drivers of vegetation temporal dynamics in Hunan Province of China during 2002-2020].
{Author}: Wang RR;Li XM;Gan DX;Liu HY;Tang L;Cai ZW;
{Journal}: Ying Yong Sheng Tai Xue Bao
{Volume}: 35
{Issue}: 5
{Year}: 2024 May
暂无{DOI}: 10.13287/j.1001-9332.202405.023
{Abstract}: Understanding the influences of climate change and human activities on vegetation change is the foundation for effective ecosystem management. Based on the 250 m MODIS-NDVI data from 2002 to 2020, we employed Theil-Sen Median trend analysis and the Mann-Kendall test to quantify vegetation change in Hunan Province. By combining with meteorological, nighttime light index, land cover and other data, residual analysis and correlation analysis, we examined the impacts of human activities and climate change on vegetation dynamics at both the pixel level and the county level. The results showed that the normalized difference vegetation index (NDVI) in Hunan Province exhibited a spatial pattern of "overall improvement with localized degradation" during 2002-2020. Approximately 64.9% of the study area experienced significant vegetation improvement, mainly occurring in the western and central-southern parts of Hunan Province. 1.4% of the study area experienced significant vegetation degradation, mostly in the newly developed urban areas and the farmland in the Dongting Lake Plain. Human activities and climate change jointly promoted vegetation improvement in 67.9% of the study area. Human activities and climate contributed to 96% and 4% of the NDVI change, respectively. At the county level, human activities contributed to over 80% of the NDVI change in each district or county. The impacts of human activities on vegetation change exhibited significant spatial heterogeneity. Urban expansion led to vegetation degradation in the newly developed areas, while vegetation growth appeared in the old developed urban areas. The ecological restoration projects promoted vegetation restoration in the western part of Hunan Province. This study could help us better understand the spatiotemporal variations of vegetation and their responses to climate change and human activities, which would offer scientific basis for effective ecological restoration policy.<BR>研究气候变化和人类活动对植被变化的影响是有效生态系统管理的基础。本研究基于2002—2020年250 m MODIS-NDVI数据,采用Theil-Sen Median斜率估计和Mann-Kendall趋势分析从像元尺度量化了湖南省植被动态演变趋势;结合气象、夜间灯光指数、土地覆盖等数据,采用残差分析和相关分析等方法,从像元和县域两个尺度揭示了人类活动和气候变化对植被动态演变的影响。结果表明: 2002—2020年,湖南省归一化植被指数(NDVI)动态演变呈“整体改善、局部退化”的空间格局,显著改善的区域占研究区总面积的64.9%,主要分布于湖南省西部和中南部;显著退化的区域占研究区总面积的1.4%,主要分布于城市化区域和洞庭湖平原的耕地区域。人类活动和气候变化共同促进研究区67.9%的植被改善;人类活动和气候变化单独对植被NDVI动态演变的贡献率分别为96%、4%;人类活动对所有区县植被演变的贡献率均超过80%。人类活动对植被演变的影响存在显著空间异质性。城市扩张导致新城区植被退化,但老城区出现植被恢复的现象;生态工程则促进了湖南省西部植被恢复。本研究结果有助于深入认识湖南省植被演变时空格局及其对气候变化和不同人类活动的响应,可为制定有效的生态恢复策略提供科学依据。.