Spatiotemporal Evaluation and Driving Mechanism of Land Ecological Security in Yan’an, a Typical Hill-Gully Region of China’s Loess Plateau, from 2000 to 2018

Abstract

Forest landscape restoration and ecosystem of Loess Plateau have enhanced prominently, since the policy implementation (1999) of the Grain for Green Project in China. Land ecological security (LES) performs an extremely critical function for protecting vulnerable land resources and sustaining forest ecosystem stability. Predecessors’ studies substantially concentrate on biophysical and meteorologic variables using numerous grounded methodologies, little research has been launched on systematic natural-socio-economic-ecological relationships and how these contributions and regulations for LES evaluation. Here, pressure-state-response (PSR) model was used to establish the evaluation system of LES in regional-scale, and LES was classified into five levels measured by ecological security index (S), including high (S ≥ 0.75), medium−high (0.65 ≤ S < 0.75), medium (0.55 ≤ S < 0.65), medium−low (0.45 ≤ S < 0.55), and low (S < 0.45) level, for systematically analyzing its spatiotemporal distribution characteristic and response mechanism to explanatory variables in Yan’an, northwest China, from 2000 to 2018. The results demonstrated that: (1) LES status was mainly characterized by medium−high level and medium level, and maintained profound stability. (2) zone with medium−high LES level was mainly concentrated in western and southern regions, continuously expanding to northeast regions, and possessed the largest territorial area, accounting for 37.22–46.27% of the total area in Yan’an. (3) LES was primarily susceptible to normalized differential vegetation index, vegetation coverage, and land surface temperature with their optimal impacting thresholds of 0.20–0.64, 0.20–0.55, and 11.20–13.00 °C, respectively. (4) Normalized differential vegetation index and vegetation coverage had a significant synergistic effect upon LES based on their interactive explanation rate of 31% and had significant variation consistency (positive and negative) with LES, which were powerfully suggested to signal the intensification of the regional eco-security level in the persistent eco-greening process.

A high‐accuracy vegetation restoration potential mapping model integrating similar habitat and machine learning

“…The main measures of the GFG Program were to ban grazing on hillsides and return cultivated land to forest and grass. After more than two decades of the GFG project, the vegetation coverage in Yan'an has increased by 50% (He et al, 2021; Wen et al, 2021). In this paper, VRP denotes the maximum vegetation coverage that can sustainably survive in the natural environment.…”

Optimal Allocation of Slope Ecological Restoration for the Climate Change Mitigation and Natural Function Improvement

“…At present, the evaluation index of ecological restoration focused on the regulation of ecological function and hydrological process (Nunes et al, 2016;Li et al, 2018;He Z. et al, 2019), such as peak reduction of the runoff, landscape pattern, and ecological service value. Most researchers evaluated ecological restoration, respectively, from the above two aspects.…”