Articles · Open Access Policy
Abstract
Seasonal flooding, hydrological connectivity, habitat heterogeneity and nutrient exchange are essential for providing a diversity of aquatic communities in floodplain ecosystems. Human activity such as river channelisation, embankments, drainage of wetlands and agricultural development has significantly impacted these ecological processes, causing fragmentation of these systems and loss of biodiversity. The reversion of degraded floodplain habitats represents an opportunity to restore aquatic species diversity, enhance ecological connectivity and ecosystem functioning. This review provides an overview of the recovery trends of aquatic biodiversity after floodplain restoration, and specifically for fish, aquatic macroinvertebrates, riparian animals and habitat-associated biological communities. The review found evidence on the long-term changes in biodiversity, hydromorphological rehabilitation, habitat diversity and indicators of restoration success. Special focus is placed on the differences in recovery rates
between taxonomic groups and the effect of the length of time since restoration, the seasonality of the hydrological regimes, and habitat connectivity. The literature reviewed shows that restoration can enhance aquatic biodiversity, with some recovery being more pronounced than others, depending on environmental conditions and the ecological attributes of restored habitats. The review also highlights problems related to the lack of completion of the rehabilitation of the habitats, of monitoring, and also differences in the ecological response between the aquatic and terrestrial ecosystems. A holistic restoration plan which includes historical assessment, hydrological reconnection, habitat diversification and long-term biodiversity monitoring is recommended. The results highlight the need for restoring ecological processes and not just physical habitat conditions in order to restore to sustainable floodplain conditions.