| 摘要: |
| 探究植被叶面积指数(Leaf area index, LAI)时空变化特征及其与影响因子之间的关系,对解析西南地区植被动态变化和制定区域植被资源管理框架具有显著意义。本文基于MODIS LAI和气象因子,结合残差分析、一阶差分多元线性回归分析和相对贡献分析等数学模型,揭示气候变化和人类活动对西南地区植被LAI变化的相对贡献,定量区分各气候因子(平均气温、降水和太阳辐射)对植被LAI变化的敏感性和贡献率。结果表明:(1)2000~2022年西南地区及各省份植被LAI均呈上升趋势,云南植被LAI上升速率最快,四川植被LAI上升速率最低。空间尺度上,西南地区植被LAI极显著上升的区域呈条带状由东北贯穿至西南,以及东南部分地区。西南地区及各省份植被LAI呈上升趋势的区域面积占比均大于呈下降趋势的区域面积占比。(2)人类活动对研究区植被LAI相对贡献为74.29%,远高于气候变化的25.41%。省级尺度上,人类活动对各省植被LAI变化的相对贡献均大于气候变化,其中,人类活动对重庆植被LAI变化的相对贡献最大,为86.13%,对四川植被LAI变化的相对贡献最小,为70.03%。(3)2000~2022年平均气温、降水和太阳辐射对西南地区植被LAI变化主要表现为负向影响,且影响量主要集中在–0.002~0之间。总体上,平均气温、降水和太阳辐射对西南地区植被LAI变化的贡献率分别为47.88%、31.25%和20.87%。省级尺度上,平均气温对云南和广西植被LAI变化主要呈正向影响,降水对贵州、四川和广西植被LAI变化主要呈正向影响,而太阳辐射对重庆、贵州、四川和广西植被LAI变化主要呈正向影响。研究结果可为气候变化背景下西南地区植被资源动态管理提供参考。 |
| 关键词: 西南地区 叶面积指数 气候变化 人类活动 相对贡献 敏感性 |
| DOI： |
| 投稿时间：2024-10-14修订日期：2024-12-30 |
| 基金项目:广西重点研发计划项目(编号:桂科AB22080080)； 高分辨率对地观测系统重大专项政府综合治理应用于规模化产业化示范项目(编号:84-Y50G25-9001-22/23)。 |
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| Quantitatively Assessing the Impacts of Climate Change and Human Activities on Vegetation Leaf Area Index in Southwestern China |
|
Li Zhenxi, Xie Zongyin
|
| (Guangxi Natural Resources Remote Sensing Institute) |
| Abstract: |
| Exploring the spatio-temporal variation characteristics of the leaf area index (LAI) of vegetation and its relationship with influencing factors is of significant importance for understanding the dynamic changes of vegetation in Southwest China and formulating regional vegetation resource management frameworks. Based on MODIS LAI data and meteorological factors, combined with mathematical models such as residual analysis, first-order difference multivariate linear regression analysis, and relative contribution analysis, this study reveals the relative contributions of climate change and human activities to the variation of vegetation LAI in Southwest China, and quantitatively distinguishes the sensitivity and contribution rates of various climatic factors (average temperature, precipitation, and solar radiation) to the changes in vegetation LAI. The results indicate that: (1) On the temporal scale, the vegetation LAI in Southwest China and its provinces has shown an increasing trend from 2000 to 2022, with Yunnan having the fastest increase and Sichuan the slowest. Spatially, the areas with significant increases in vegetation LAI in Southwest China extend in a strip from northeast to southwest, as well as in some southeastern regions. The proportion of areas with an increasing trend in vegetation LAI is larger than that with a decreasing trend in Southwest China and its provinces. (2) The relative contribution of human activities to the vegetation LAI in the study area is 74.29%, much higher than the 25.41% contributed by climate change. At the provincial level, the relative contribution of human activities to the changes in vegetation LAI is greater than that of climate change in all provinces. Among them, human activities contribute the most (86.13%) to the changes in vegetation LAI in Chongqing and the least (70.03%) in Sichuan. (3) From 2000 to 2022, the average temperature, precipitation, and solar radiation mainly had negative impacts on the changes in vegetation LAI in Southwest China, with the impact mainly ranging from –0.002 to 0. Overall, the contribution rates of average temperature, precipitation, and solar radiation to the changes in vegetation LAI in Southwest China are 47.88%, 31.25%, and 20.87%, respectively. At the provincial level, the average temperature mainly has a positive impact on the changes in vegetation LAI in Yunnan and Guangxi, precipitation mainly has a positive impact on the changes in vegetation LAI in Guizhou, Sichuan, and Guangxi, and solar radiation mainly has a positive impact on the changes in vegetation LAI in Chongqing, Guizhou, Sichuan, and Guangxi. The findings of this study can provide a reference for the dynamic management of vegetation resources in Southwest China under the background of climate change. |
| Key words: Southwestern China leaf area index climate change human activities relative contributions sensitivity |
