Vegetation cover change and restoration potential in the Ziwuling Forest Region, China

Since the implementation of "Grain for Green" program in 1999, remarkable changes have taken place in the vegetation of the Loess Plateau, China, especially in the forests. The Ziwuling Forest Region is an important ecological forest area in the central zone of the Loess Plateau. The spatiotemporal variation of the vegetation cover and vegetation restoration potential in the Ziwuling Forest Region was studied using the NDVI data, based on geographical spatial analysis technology, Hurst exponent analysis and statistical analysis. From 2001 to 2019, vegetation cover in forest region increased significantly. The average growth rate of vegetation cover was 6.49%, and NDVI increased significantly in 84.66% of the area (p < 0.05), with an average annual growth rate of 0.0045 a-1. In 2019, it reached the maximum value of 0.833, and the Hurst index indicates that 35.02% of the area will show a benign development trend in the future. The vegetation coverage was linear negatively correlated with the aridity index, and the fitting degree in steep slope area (R2 > 0.5) was better than that in gentle slope area (R2 > 0.4). The average vegetation restoration potential in the study area was 0.837. Of the regional vegetation coverage, 72.47% is close to or has exceeded the vegetation restoration potential, and the vegetation restoration degree in the northern and eastern regions is relatively high. The existing vegetation coverage and vegetation restoration potential in Ziwuling Forest Region are high, so the existing vegetation restoration measures should be maintained to avoid damage to the vegetation in the area. This study has important guiding significance for the implementation of vegetation restoration and ecological protection policies on the Loess Plateau.