基于小波变换的生态系统服务权衡尺度效应与影响因素研究——以珠江三角洲为例

识别生态系统服务间的多尺度权衡关系及其影响因素对于指导管理决策和推进可持续发展至关重要,然而尺度响应特征及差异变化成因尚不明确,其中一个重要原因是缺乏科学合理的尺度划分方法。本文评估了珠三角地区的土壤保持、水源涵养、生境质量、自然游憩共4种关键生态系统服务量,基于小波变换的特征尺度估算方法,确定了研究权衡关系的最佳聚合规模序列。应用相关性分析和地理探测器方法,定量化识别权衡强度在各个尺度的影响因素,并比较了不同尺度间主导影响因素的差异特征。结果表明：① 权衡强度在6条样线上的特征尺度突出,2000~11500 m是研究权衡关系的最佳尺度序列范围。② 自然游憩与水源涵养、生境质量之间存在协同关系,自然游憩与土壤保持互为权衡关系。三对服务组合之间的相互作用大多随着尺度的增大而增强,特别是在县级行政管理规模上,所有配对服务表现出最强的协同或最弱的权衡关系。③ 植被覆盖度对权衡强度的驱动作用突出且相对稳定。地形因素是小尺度范围内权衡关系变化的主导影响因素,而气候因素和景观格局指数在较大尺度的影响作用显著。本研究通过优化传统的多尺度研究序列构建方法,为调控各类驱动因素以制定多级管理决策提供参考。

Scale effects on ecosystem service trade-off and its influencing factors based on wavelet transform: A case study in the Pearl River Delta,China

Identifying the multi-scale trade-offs and their influencing factors among ecosystem services (ESs) is crucial for guiding management strategies and promoting sustainable development. However, the scale response characteristics and mechanisms are still very unclear due to the lack of scientific scale division method. This paper used empirical statistics and biophysical models to assess four typical ESs, including two supporting services (soil conservation and habitat quality), one regulating service (water conservation) and one cultural service (natural recreation). The characteristic scales of the trade-offs between cultural and other three types of ESs were obtained based on the continuous wavelet transform. By combining the ecological feature scales with the administrative management scales, the optimal scale sequence for the trade-off study was finally constructed. Then we applied correlation analysis and geographical detector to quantitatively identify the influencing factors of ES trade-off at each scale and compare the difference characteristics of dominant factors between different scales. The results showed that: (1) The characteristic scales of ES trade-off were prominent along the six transects, and 2000-11500 m was the optimal scale sequence range for the study on trade-off. (2) There was an identified trade-off between natural recreation and soil conservation, and natural recreation showed stable synergistic relationships with water conservation and habitat quality. Most correlations of the three paired ESs enhanced as the scale increased, and the strongest synergies or the weakest trade-offs were found at the county-level administrative scale, making it the best scale unit for making and implementing ecosystem management decisions. (3) Vegetation coverage was the most important and relatively stable driving force throughout the whole scale sequence, while the influences of other factors mutated at the township level. It was proved that the topography was the major influencing factor on smaller scales, and the landscape metrics and climatic factors gradually became involved in controlling ES trade-offs with the increase of scale. In conclusion, this study optimizes the traditional unit division method by introducing wavelet transform, which provides a scientific and powerful premise for a comprehensive understanding of the multi-scale trade-offs and influencing factors among ESs. Our results will provide a reference for regulating various driving factors to make multi-level management decisions in the Pearl River Delta region.