Assessment of ecological integrity and analysis of its influencing factors in Zhangjiakou municipality

Anthropogenic disturbances, such as urbanization and agricultural production, significantly contribute to the degradation of regional ecosystems. While the concept of human integrated impact assessments is widely recognized, there is a notable absence of regional assessment methods based on ecological integrity in China. This study addresses this gap by examining Zhangjiakou, a critical area for water source conservation and ecological support for Beijing. We employ a landscape condition model to evaluate six anthropogenic disturbance indicators: slope gradient of cropland, distance from grassland to the nearest settlement, distance from surface water to the nearest settlement, urban area size, road grade, and railway grade. These indicators encompass four domains: agricultural and animal husbandry production, surface water utilization, urbanization, and transportation infrastructure. To quantify the impact scores and maximum impact radius for each indicator, we used a participatory method. This approach led to the creation of separate data layers, each numerically valued from 0 to 1, for each disturbance indicator. These layers were then synthesized into a continuous ecological integrity index using the product method. We applied spatial autocorrelation analysis, hot spot analysis, sensitivity analysis, and commonality analysis to explore the spatial distribution, clustering characteristics, and primary influencing factors of ecological integrity for the years 2000 and 2022. Our findings reveal a distinct spatial distribution pattern in Zhangjiakou: high ecological integrity is observed in the eastern regions, whereas lower integrity characterizes the central, northern, and western areas. This pattern is influenced by regional resources, transportation, and development orientation. Between 2000 and 2022, we observed a significant trend of polarization in human impact on ecological integrity. Specifically, human disturbance decreased in areas with high ecological integrity but increased in areas with lower integrity, indicating diverse levels of anthropogenic influence across different regions. In the eastern part of Zhangjiakou, ecological restoration projects have led to patches of high-integrity forests. Conversely, road construction has created a low-integrity spatial distribution pattern in the central and northern regions, emanating from urban centers and radiating along major roads. The western region, impacted by agricultural and pastoral activities, does not exhibit clear clustering characteristics of ecological integrity. Our study identifies cropland, roads, and grassland as the primary factors influencing the ecological integrity of Zhangjiakou. To mitigate these impacts, we recommend enhancing forest landscape restoration in the eastern region. For the central and northern regions, clear boundaries for highway development should be delineated in accordance with ecological protection guidelines. Additionally, efforts to convert farmland to grassland in the western region should be intensified to improve water supply and enhance ecological carrying capacity. These initiatives aim to establish an ecological security barrier in the northwest of Beijing and improve the region’s resilience to anthropogenic pressures. This study contributes an effective scientific methodology and technical reference for regional ecosystem human integrated impact assessments. It underscores the importance of tailored management interventions based on the spatial aggregation of ecological integrity to address specific challenges posed by anthropogenic disturbances. Such targeted interventions are crucial for promoting sustainable development and enhancing ecological resilience in regions under significant human pressure.