Comparing the long-term effects of artificial and natural vegetation restoration strategies: A case-study of Wuqi and its adjacent counties in northern China

The significant increase in vegetation coverage in northern China over the past two decades has attracted worldwide attention. Revegetation has been completed via artificial and natural restoration techniques, and the relative performance of each needs to be further explored. Although some studies have focused on the comparison between artificial and natural methods in vegetation restoration from a micro-perspective, there is a lack of evidence at the regional scale. This study considers Wuqi County and its adjacent areas of the Loess Plateau in northern China as our study area. First, natural and artificial restoration areas were identified. Then, the restoration sustainability of different restoration strategies and the adjustment effect of climate factors in the relationship between vegetation restoration strategy choice and vegetation restoration sustainability were analyzed. We found that the vegetation restoration strategies employed varied between local jurisdictions. In areas dominated by artificial restoration, vegetation coverage increased over a short period, but the growth rate diminished in the long term. In comparison, in areas mainly dominated by natural restoration, although the growth rate of revegetation was not very high in the short term, it was stable in the long term. In addition, the impact of vegetation restoration strategies on vegetation restoration sustainability exhibited spatial heterogeneity, and the temperature, humidity, and wind speed further affected strategy outcomes. This study provides a new perspective for vegetation restoration strategy evaluation and is expected to serve as a reference for the optimization of relevant ecological policies in the future.