Unravelling wetland connectivity: a comparative analysis of landscape structure and connectivity between natural and unnatural (artificial) wetlands in Van Sub-basin

Abstract

This study compares natural and artificial wetlands in Türkiye’s Van sub-basin, exploring human impacts on landscape connectivity and species diversity. It examines how habitat fragmentation affects species isolation and long-term viability, involving 14 natural and 9 artificial wetlands to improve conservation strategies. A four-stage methodology was used to analyze wetland connectivity. First, focal nodes and resistance surfaces were defined using Corine 2018 data and topographic wetness index (TWI). Second, resistance maps were created. Third, habitat fragmentation was assessed using Fragstats software, analysing metrics like PLAND, and CONNECT. Finally, connectivity was modeled using Circuitscape software. The study revealed that natural wetlands, despite their dominance (PLAND = 89.89% for lakes), did not ensure effective connectivity. Artificial wetlands often served as crucial connectivity points, with a cumulative current value of 0.99. Land cover characteristics significantly impacted connectivity, with agricultural and forest areas promoting better connectivity. The combined analysis showed a slight increase in connectivity value (4.01687) compared to natural wetlands alone (4.01654) but a substantial increase (305%) compared to artificial wetlands alone. Artificial wetlands significantly contribute to landscape connectivity, particularly in areas with heterogeneous agricultural landscapes. Effective conservation should consider both wetland types and focus on enhancing connectivity across landscapes to mitigate habitat fragmentation and support resilient ecosystems. The study highlights the importance of integrated approaches, as the combined natural and artificial wetland network improved overall landscape connectivity by 0.0082% compared to natural wetlands alone.