青海省果洛藏族自治州植被生长季NPP时空变化及其驱动机制
汤宝虎 1安福元 1胡锦荣 1殷佳秋 1盖龙飞(1,2）1
作者信息
- 1. 青海省果洛藏族自治州植被生长季NPP时空变化及其驱动机制
- 折叠
摘要
植被净初级生产力（NPP）作为表征植被光合固碳能力的关键指标，对评估生态系统碳汇功能及其对气候变化与人类活动的响应具有重要意义。本研究以青藏高原腹地的生态脆弱区——青海省果洛藏族自治州为研究对象，基于2000—2020年生长季（5—9月）MODIS NPP数据，结合自然因子和人类活动数据，采用趋势分析、变异系数、随机森林模型等方法，系统揭示了果洛州植被NPP的时空演变特征及其驱动机制。结果表明：（1）研究区植被NPP呈波动上升趋势，季节内分异显著，8月增长最为显著，5月波动最大且增长趋势最不明显。（2）土壤湿度是全年主导驱动因子，其次为高程，放牧贡献随海拔呈U型布，太阳辐射仅在5月出现贡献峰值。（3）海拔梯度上存在清晰的驱动谱带，低海拔带放牧与太阳辐射协同，中低海拔带6月出现辐射异常窗口，中高海拔带为夏季降水主导、秋季土壤湿度主导，高海拔带为春季最高温主导返青启动，秋季最低温主导生长终止。
Abstract
Under the background of global warming, the structure and function of terrestrial ecosystems have undergone profound changes. As a key indicator of vegetation photosynthetic carbonsequestration capacity, net primary productivity (NPP) plays a critical role in assessing carbon sink functions in ecosystems and their responses to climate change and anthropogenic activities. This study focuses on the Golog Tibetan Autonomous Prefecture in Qinghai Province, an ecologically fragile area located in the hinterland of the Qinghai-Xizang Plateau. Using MODIS-derived growing-season (May-September) NPP data from 2000 to 2020, combined with natural environmental and anthropogenic factors, this study systematically investigated the spatiotemporal dynamics and driving mechanisms of vegetation NPP using trend analysis, coefficient of variation analysis, and random forest modeling. The results showed that (1) vegetation NPP exhibited a fluctuating but overall increasing trend, with significant intraseasonal variability; the strongest increase in vegetation NPP occurred in August, whereas May showed the largest interannual variability and the lowest rate of increase. (2) Soil moisture was the dominant driver of vegetation NPP throughout the growing season, followed by elevation. The contribution of livestock grazing pressure on vegetation NPP exhibited a U-shaped pattern along the altitudinal gradient, whereas solar radiation made a substantial contribution only in May. (3) A distinct altitudinal gradient in the dominant driving factors was identified. At low altitudes, grazing pressure and solar radiation acted synergistically. At low-middle altitudes, an anomalous radiation-dominated window appeared in June. At upper-middle altitudes, summer precipitation became the primary controlling factor, while soil moisture dominated during autumn. At high altitudes, maximum spring temperature primarily regulated the start of vegetation greening, whereas minimum autumn temperature controlled the end of the growing season.关键词
植被净初级生产力/时空变化/自然因素/人类活动/果洛藏族自治州Key words
Net Primary Productivity/spatiotemporal variations/natural factors/human activities/Golog Tibet-an Autonomous Prefecture引用本文复制引用
汤宝虎,安福元,胡锦荣,殷佳秋,盖龙飞(1,2）.青海省果洛藏族自治州植被生长季NPP时空变化及其驱动机制[EB/OL].(2026-09-11)[2026-09-13].https://chinaxiv.org/abs/202609.00103.学科分类
环境科学基础理论
