Zoning of ecological function monitoring areas and spatial layout of monitoring sites in the ecological space of Chifeng city

Abstract：Background Chifeng city, located at the intersection of the “Three-North Shelterbelt” and the agro-pastoral ecotone of northern China, represents a critical ecological transition zone characterized by diverse ecosystem types and essential ecological functions such as windbreak, sand fixation, and water conservation. However, the existing ecological monitoring network lacks adequate spatial representativeness and functional precision, constraining the accuracy of ecological compensation and ecosystem service assessments. To address these limitations, this study aims to develop a scientifically rigorous framework for ecological function zoning and monitoring layout in Chifeng’s ecological space, thereby improving the effectiveness and continuity of long-term ecosystem monitoring. Methods Based on multi-source datasets encompassing climate, vegetation, topography, and dominant ecological functions, a three-tier ecological function zoning system was constructed using ArcGIS Pro 3.0. Overlay analysis was integrated with the Merging Criteria Index (MCI) and relative error control to delineate spatially homogeneous ecological subregions. Stratified sampling and field investigations, conducted from July to December 2022, were employed to optimize the spatial arrangement of monitoring sites across forest, grassland, and wetland ecosystems. A total of 122 monitoring plots were established within eight ecological functional zones to ensure representativeness, spatial integrity, and functional coherence. Results 1) The proposed zoning scheme classified Chifeng into two primary temperature zones (middle and warm temperate), two humidity types (semi-arid and semi-humid), and eight tertiary ecological functional subregions, reflecting distinct spatial heterogeneity of ecosystem types. The overall zoning accuracy reached 96.68%, with northern and central zones (Ⅱ(c)1–Ⅱ(c)3) exhibiting the highest consistency with vegetation distribution and major ecological projects. 2) Spatial analysis of ecosystem resources revealed clear differentiation among forest, grassland, and wetland systems. Forest ecosystems dominated the northern and central regions, particularly Ⅱ(c)2, featuring structurally complex and species-rich communities. Grasslands were mainly distributed in Ⅱ(c)2 and Ⅲ(b)2, forming the core typical steppe areas, while wetlands were clustered along river valleys in Ⅱ(c)1 and Ⅱ(c)2, constituting the city’s main wetland zones. 3) In total, 122 monitoring sites were arranged—79 for forest, 30 for grassland, and 13 for wetland ecosystems. The Ⅱ(c)2 zone exhibited the highest site density, ensuring comprehensive coverage of key ecosystem types and ecological gradients. The established monitoring network effectively captured spatial transitions from natural to human-impacted ecosystems and aligned well with national ecological engineering and policy implementation zones. Conclusions This study establishes a function-oriented ecological zoning and monitoring framework that significantly enhances the spatial and functional representativeness of ecological monitoring in Chifeng city. The integrated “zoning–sampling–field validation” approach improves monitoring precision, supports ecological product valuation and compensation assessments, and provides a replicable technical model for constructing ecological monitoring networks in northern fragile ecosystems.