Influence of Agricultural Land Conversion on the Ecological Integrity of Inland Wetland Networks

Inland wetlands are components of landscape networks, which are dynamic – they manage water dynamics, sequester nutrients, contribute to biodiversity and help maintain rural livelihoods. Hydrological changes to wetlands, including drainage, infilling, bunding, channel modification, and increasing areas of cultivation is a recurring stress on these systems, as it can lead to a loss of wetland habitat and to a loss of the hydrological links needed to maintain the functions of wetlands. This paper critically synthesizes evidence from 2014 to 2022 on the impact of agricultural conversion on the ecological integrity of inland wetland networks. The review compiles pathways connecting land-cover change and wetland area loss, fragmentation, altered hydroperiod, water quality decline, and habitat simplification and changes in ecosystem services. It also develops a conceptual assessment framework that integrates landscape configuration, hydrological connectivity, water quality, habitat condition and biological response. The reviewed evidence also shows that the ecological impacts of conversion can occur outside the reclaimed area, such as changes to the surrounding farmland, drainage infrastructure and flow control, which may have impacts on remnant wetlands via flow modification, sediment delivery and movement between habitat patches. A network perspective provides more information than a wetland-area accounting perspective. The paper calls for watershed-scale land-use planning, conservation of seasonally flooded wetlands and land-use transition corridors, nutrient management in agriculture, and restoration of hydrological processes. The proposed framework can serve as a guide for future geospatial and field-based assessments, but acknowledging that the impact level is dependent on the type of wetland, climate, topography and management history.