黄土高原典型稳定植被系统物候时空变化特征及其气候驱动机制

植被物候作为气候变化对植被影响的直观表征，关系到区域植被的可持续性，对黄土高原气候变化环境效应评估和生态系统管理具有重要意义。然而，气候变化与人类活动对植被变化的作用相互交织，分离和量化气候变化对植被的影响仍需进一步研究。为此，本研究拟在黄土高原选择没有或极少受退耕还林（草）及耕作等人类活动干扰且成熟稳定的植物群落区（称之为“典型稳定植被系统”）为研究对象，结合地面物候实际监测数据与MODIS遥感数据反演，准确识别典型稳定植被系统的物候期信息，探明黄土高原植被物候的时空变化特征；采用偏最小二乘法等方法辨析多气候要素对植被物候的非线性时间效应，识别影响植被物候期变化的关键气候因子与作用模式，揭示植被物候的气候驱动机制；在此基础上，构建植被物候过程模型，预测未来多种气候变化情景下的植被变化趋势。本研究可为黄土高原植被可持续管理和生态系统应对气候变化提供科技支撑。

As an intuitive representation of the impact of climate change on vegetation, vegetation phenology is related to the sustainability of regional vegetation. It is essential for the assessment of the environmental effects of climate change and ecosystem management on the Loess Plateau. However, as the effects of climate change and human activities on vegetation change are intertwined, further research is needed to isolate and quantify the impact of climate change on vegetation. Therefore, the mature and stable plant community areas (referred to as "typical stable vegetation system") that are not or rarely disturbed by human activities such as afforestation and farming on the Loess Plateau are selected as the research object in this study. The phenological indices of the typical stable vegetation system are accurately identified by combining the actual monitoring data of ground phenology and MODIS remote sensing data inversion. The spatiotemporal characteristics of vegetation phenology on the Loess Plateau are analyzed. Partial least squares and other methods are used to analyze the non-linear time effect of multi-climate elements on vegetation phenology, and to identify the key climatic factors and modes of action that affect changes in vegetation phenology, which aim to reveal the climate-driven mechanism of vegetation phenology. On this basis, phenological process models of vegetation are constructed to predict the trend of vegetation change under various climate change scenarios in the future. This proposed project can provide scientific and technological support for the sustainable management of vegetation and the response of ecosystems to climate change on the Loess Plateau.