Terrain or climate factor dominates vegetation resilience? Evidence from three national parks across different climatic zones in China

Vegetation resilience (VR), providing an objective measure of ecosystem health, has received considerable attention, however, there is still limited understanding of whether the dominant factors differ across different climate zones. We took the three national parks (Hainan Tropical Rainforest National Park, HTR; Wuyishan National Park, WYS; and Northeast Tiger and Leopard National Park, NTL) of China with less human interference as cases, which are distributed in different climatic zones, including tropical, subtropical and temperate monsoon climates, respectively. Then, we employed the probabilistic decay method to explore the spatio-temporal changes in the VR and their natural driving patterns using Geographically Weighted Regression (GWR) model as well. The results revealed that: (1) from 2000 to 2020, the Normalized Difference Vegetation Index (NDVI) of the three national parks fluctuated between 0.800 and 0.960, exhibiting an overall upward trend, with the mean NDVI of NTL (0.923) ​> ​HTR (0.899) ​> ​WYS (0.823); (2) the positive trend decay time of vegetation exceeded that of negative trend, indicating vegetation gradual recovery of the three national parks since 2012; (3) the VR of HTR was primarily influenced by elevation, aspect, average ​annual temperature change (AATC), and average annual precipitation change (AAPC); the WYS’ VR was mainly affected by elevation, average ​annual precipitation (AAP), and AAPC; while the terrain factors (elevation and slope) were the main driving factors of VR in NTL; (4) among the main factors influencing the VR changes, the AAPC had the highest proportion in HTR (66.7%), and the AAP occupied the largest area proportion in WYS (80.4%). While in NTL, elevation served as the main driving factor for the VR, encompassing 64.2% of its area. Consequently, our findings indicated that precipitation factors were the main driving force for the VR changes in HTR and WYS national parks, while elevation was the main factors that drove the VR in NTL. Our research has promoted a deeper understanding of the driving mechanism behind the VR.