# An Analysis of Spatial Variation in Human Impact on Forest Ecological Functions
## 5 Conclusions and Implications  
Taking the Yellow River Basin (YRB) as a typical area, we use multiple linear regression (MLR) and geographically weighted regression (GWR) modeling to compare and analyze the impacts of human activities on forest ecological function (FEF) in county-level administrative areas in China. The main findings are as follows:  
First, the county-level FEF in the YRB is poor overall but with significant regional differences, showing an obvious positive spatial agglomeration. The agglomeration manifests predominantly as high-high and low-low clusters, with high-high areas primarily clustered in the southern and central mountainous areas, whereas low-low areas are distributed in the upstream warm temperate steppe and desert-grassland regions.  
Second, human activities exert a substantial impact on forest ecological function, and the coefficient and significance level of each factor show marked spatial heterogeneity. Trend analysis indicates that FEF is more sensitive to the increase in living land, population density, and forest protection in the east-west direction. And in the north-south direction, FEF is more easily affected by agricultural development, population growth and urbanization.  
Third, it is recognized that FEF is more dependent on natural factors in areas where human activities are scarce. We find that in some regions with considerable human activities, FEF may still ultimately depend on the natural endowments, which is due to the inter-constraint or counteract effects among different human activities. In regions with more natural forest resources, economic development, especially agricultural production, has significant dampening effects on FEF, as does the encroachment on ecological land by irrational expansion of productive and living lands. In the water-scarce counties, population clustering and forest protection are the most efficient for enhancing FEF. As for the Yellow River Delta with salinized soil, FEF can be improved through accelerated urbanization.  
Accordingly, we propose the following recommendations for bettering the forest ecological functions:  
First, we should take full account of the limitations of climatic conditions. We should reduce human disturbances and promote natural ecological recovery as much as possible in areas that have not been that developed.  
Second, counties should formulate measures to improve FEF in line with local conditions. More efforts could be put into raising the efficiency of available resources in counties with abundant natural endowments. And in less endowed counties, the improvement of FEF should be on the premise of increasing vegetation cover through ecological projects.  
Third, counties should articulate their positions in regional ecological protection, considering the possible repercussions of ecological measures on neighboring regions.  
Leveraging the comprehensive effects of combined ecological measures is imperative, avoiding reliance on single ecological engineering or restoration measures.  
Conceptualization, X.Z.; data curation, L.F.; formal analysis, Q.W. and X.Z.; methodology, Q.W.; software, Q.W.; funding acquisition, X.Z.; writing--original draft, Q.W.; writing--review and editing, Y.D., R.P.S. and X.Z. All authors have read and agreed to the published version of the manuscript.  
This work was supported by the Fundamental Research Funds of Chinese Academy of Forestry (grant number CAFYBBB2023 MB019); China Scholarship Council (grant number 202203270009); and the Fundamental Research Funds of Chinese Academy of Forestry (grant number CAFYBBB2023 PA006-02).  
Not applicable.  
Data Availability Statement: Data will be made available on request.  
The authors declare that they have no conflicts of interest.