Moran's I of VRPAD: A human activity-sensitive spatial pattern index for vegetation restoration evaluation

Vegetation is a fundamental component of ecosystems, and its coverage plays a crucial role in ecosystem assessments. While the Vegetation Coverage Degree (VCD) reflects vegetative growth, the spatial distribution patterns of vegetation are of greater interest. Traditionally, detecting vegetation coverage patterns and their changes involved measuring the spatial autocorrelation of VCD, with Moran's I being the prevalent indicator. However, VCD is influenced by regional natural resource endowments, causing natural patterns to largely determine vegetation coverage patterns. Consequently, Moran's I of VCD lacks cross-regional comparability, making it unsuitable for evaluating differences in vegetation restoration caused by human-driven ecological restoration efforts in various regions. In this study, we introduce the Vegetation Restoration Potential Achievement Degree (VRPAD), calculated by dividing the VCD by the theoretical maximum VCD determined based on local natural conditions. VRPAD effectively filters out the influence of natural resource endowments, thereby better reflecting the outcomes of human intervention. Therefore, the proposed Moran's I of VRPAD in this paper is expected to be sensitive to human activities and serve as a landscape-level indicator. More importantly, as disturbances minimizes after the implementation of vegetation restoration projects, VRPAD and its Moran's I theoretically tend towards 1 and 0, respectively, over time. The magnitude and variations of this novel indicator provide broad spatiotemporal comparability, which is essential for evaluating the effectiveness of ecological restoration and delineating the stages of vegetation restoration.