物候过渡带变迁遥感监测及其对气候变化的响应研究

The pheno-tone dynamics is an effective indicator of ecological response to climate change. It is of great significance to carbon sequestration, energy and matter exchange between land and atmosphere, biodiversity conservation, net primary productivity estimation, and ecological carrying capacity evaluation. This project aims to tackle the issues associated with pheno-tone dynamics analysis. In this project, phenoregions with more homogeneous phenological features were firstly delineated based on remotely sensed images. On the basis of phenoregions, a pheno-tone boundary detection method, applicable to various types of boundaries, was developed. The spatio-temporal pattern of pheno-tone dynamics was analyzed in terms of appearance/disappearance, geographical shift, shape/area change, and characteristics of pheno-tones. Finally, a suite of metrics quantifying pheno-tone dynamics was designed and applied in the in-depth quantitative analysis of pheno-tone dynamics’ response to climate change. The results of this project are expected to enhance the understanding of the structure, function, transition pattern and effects of pheno-tones, and can potentially provide methodological support and scientific basis to more effective land surface phenological monitoring, pheno-tone dynamics prediction and global climate change solutions.

物候过渡带变迁是气候变化生态响应的有效“指示器”，对碳汇、地表-大气间物质与能量交换、生物多样性保护、净初级生产力估算、生态承载力评价等研究具有重要意义。针对当前物候过渡带变迁研究存在的问题，本项目借助遥感手段，从划分物候特征更为一致的物候区入手，研究具有普适性的物候过渡带范围界定方法，从物候过渡带的出现/消失、空间推移、形状/面积变化和性质变化四方面全面分析物候过渡带变迁的时空模式，并构建物候过渡带变迁的量化评价指标体系，开展其对气候变化响应的深入定量分析。研究成果有助于加强对物候过渡带结构、功能、变迁模式和变迁影响的理解，为更有效地监测地表植被物候、预测物候过渡带的变迁趋势以及应对全球气候变化提供技术支持和科学依据。

物候过渡带变迁是气候变化生态响应的有效“指示器”，对碳汇、地表-大气间物质与能量交换、生物多样性保护、净初级生产力估算、生态承载力评价等研究具有重要意义。本项目从物候过渡带划分及物候过渡带变迁分析存在的问题入手，提出了一套包含物候过渡带提取、变迁时空模式分析和变迁对气候变化响应建模的完整可行的技术方法体系。首先，本项目研发了基于DTW的模糊c-medoids聚类和Delaunay镶嵌场估计器的物候过渡带提取方法，首次实现了物候过渡带空间范围的准确界定，并突出了物候过渡带“物候”和“过渡”的本质；其次，通过将物候过渡带提取方法应用于东北林草交错生态脆弱区，提取了2003年至2017年间7个持续存在和8个间歇性存在的物候过渡带，并明晰了物候区之间的四种典型关系，即没有过渡带的明确边界，以及梯度、包含和镶嵌型过渡带；最后，构建了包括面积变化、位置变化、景观格局变化（斑块面积、破碎/聚集度、斑块形状和多样性）和空间一致性共7个方面15项指标的物候过渡带变迁指标体系，建立了物候过渡带变迁对气候变化的响应模型，深入定量分析了物候过渡带变迁受气温、降水和太阳辐射等气候因子变化的影响。研究成果有助于加强对物候过渡带结构、功能、变迁模式和变迁影响的理解，为更有效地监测地表植被物候、预测物候过渡带的变迁趋势以及应对全球气候变化提供技术支持和科学依据。