Structural connectivity of terrestrial level 3 EUNIS habitats

An analysis workflow quantifies the connectivity of terrestrial habitat types by combining continuous habitat-probability surfaces with fragmentation pressures-road infrastructure—and masking land-cover mismatches. A consistent Europe-wide set of maps quantifies structural connectivity for EUNIS Level-3 habitats, derived from 100 m habitat-probability surfaces (0–1) produced by NaturaConnect (Si-Moussi et al., 2024; Horizon EU, Task 6.3, Deliverable 6.2).Connectivity is measured using probability-weighted, normalized Effective Mesh Size (Meff_pw_norm; Jaeger, 2000) in a moving-window approach. Pixels with low probability (P < 0.1) are excluded; land-cover mismatches are masked using a CLC–EUNIS crosswalk (Si-Moussi et al., 2024) with CORINE Land Cover 2018 (EEA, 2021); and road corridors are removed using a binary OpenStreetMap roads raster. Meff is computed on probability-weighted connected components within a 10.1 × 10.1 km window and divided by the window area (102.01 km²), yielding a 0–1 fraction of effectively connected habitat per pixel.The resulting dataset offers a practical, comparable basis to describe the state of ecological connectivity for habitats of interest, including those protected under the Natura 2000 network.本分析流程通过将连续生境概率表面与道路基础设施等生境破碎化压力因子相结合，并掩膜土地覆盖不匹配区域，实现了陆地生境类型连通性的量化。一套统一的全欧地图集量化了欧洲自然信息系统（European Nature Information System, EUNIS）三级生境的结构连通性，其数据源自NaturaConnect项目生成的100米分辨率生境概率表面（取值范围0–1；Si-Moussi等，2024；地平线欧洲计划（Horizon EU），任务6.3，交付成果6.2）。连通性采用经概率加权的归一化有效网格尺寸（Effective Mesh Size, Meff_pw_norm; Jaeger, 2000），通过移动窗口法计算得到。本流程剔除了概率值低于0.1的像素；利用基于CORINE土地覆盖2018（CORINE Land Cover 2018；欧洲环境署（EEA），2021）的CLC–EUNIS交叉对照表（Si-Moussi等，2024）掩膜土地覆盖不匹配区域；并通过二值化的开放街道地图（OpenStreetMap）道路栅格移除道路廊道。有效网格尺寸（Meff）基于10.1×10.1 km窗口内的概率加权连通分量计算所得，再除以窗口总面积（102.01 km²），最终得到每个像素对应的有效连通生境占比（取值范围0–1）。本数据集可为目标生境（包括纳入Natura 2000网络（Natura 2000）保护的生境）的生态连通性现状提供一套实用且可跨区域比较的评估基准。