植被NPP趋势演替和多时间尺度变化对气候变化与人类活动的非线性响应及其预测

植被净初级生产力（NPP）是陆表碳循环的重要组成。遥感监测植被NPP动态和探究其对气候变化与人类活动的响应是全球变化研究的热点。然而植被NPP趋势演替和不同时间尺度变化及其对气候变化与人类活动的非线性响应机制尚未清楚。本项目基于野外采样、遥感估算、多时间尺度分析、机器学习和建模等方法，以我国“21世纪海上丝绸之路”沿线省份为例，研究植被NPP趋势演替和不同时间尺度变化的非线性特征；定量提取生物气候变量、地形和土壤等自然因子和土地利用变化（生态工程和城市化）、人口密度、GDP和距离道路、河流和居民点远近等人类因子的非线性影响及其相对重要性，提取气候变化和人类活动的单独、共同和耦合效应，初步探究植被NPP变化的非线性响应机制；通过模型构建和情景假设预测未来不同气候和土地利用变化情景下植被NPP趋势变化的空间格局。以期为海上丝绸之路沿线地区的生态和经济可持续发展提供理论依据和决策支持。

Vegetation net primary productivity(NPP) is an essential component of carbon cycle, and a major index to quantify the carbon source/sink of ecosystem. With global warming and rapid human activities, monitoring vegetation NPP dynamics and exploring how it responds to climate changes and human activities is a hot topic in global change. However, the trend evolution and multiple time scale changes of vegetation NPP, and their nonlinear response mechanism remains unclear. The provinces along ‘The 21st-Century Maritime Silk Road’ in China are located in the coast of East and South China with well-developed economy, where vegetation is sensitive to climate changes and human activities. In this project, as a case study of the area along ‘the 21st-Century Maritime Silk Road’ in China, by integrating field sampling, remote sensing technology, machine learning and model simulations, we will study the trend evolution and multiple timescale changes of vegetation NPP, extract the nonlinear relationships of climate changes, topography, soil properties, and human activities with the trend evolution and multiple timescales changes, identify their relative importance, and quantify the direct, shared and coupling effects of climate changes and human activities. With scenario analyses and model simulations, we will forecast the future changes of the trends of vegetation NPP under different scenarios of climate and land use changes. We hope these studies will afford decision support and theory basis for regional environmental and eco-social sustainability, and further provide ecological security for ‘The Belt and Road Initiative’.