Integrating key species distribution and ecosystem service flows to build directed ecological network: Evidence from the Shiyang River Basin, China.

Increasing landscape fragmentation is accelerating biodiversity loss and ecosystem service flow interruption, particularly in ecologically fragile arid inland river basins. Although ecological networks are widely regarded as an effective tool to mitigate habitat fragmentation, most existing models focus primarily on static spatial patterns at the landscape level and overlook individual-level dynamics driven by environmental heterogeneity, failing to capture dynamic biotic flows essential for understanding real ecological interactions and system functioning. To address this gap, a directed ecological network that integrates static spatial structures with dynamic biotic flow processes was constructed in this study, and its structural properties were evaluated using a complex network algorithm. The 2020-directed ecological network of the Shiyang River Basin consisted of 71 habitat patches and 133 ecological corridors, and the directed network showed a clear trend of species migration from the downstream desert to the upstream mountainous areas. Structural characteristics were analyzed at three levels: node, corridor, and overall network. Key habitat nodes were mainly concentrated in the upper reaches, while critical corridors were primarily distributed in the midstream and downstream areas. At the network level, the basin was delineated into four ecological functional zones, namely water conservation and biodiversity protection, oasis production, desert-oasis interaction, and desert management. A comparative analysis of undirected and directed networks demonstrated that directed networks offer distinct advantages in addressing landscape fragmentation. This process-based, directional framework enhances ecological realism, supports targeted conservation planning, and offers valuable insights for adaptive ecological governance in arid inland river basins.