Editorial: Dams and wetland biodiversity: Impacts and mitigating measures

To meet energy, water and transportation needs, an incredible amount of dams have been constructed around the world. For example, only in the Yangtze River's watershed of China, over 50,000 dams were built since 1950 (Nilsson et al., 2005; Wu et al., 2019). Dams could contribute to energy and water supply, and flood protection, but they also affect aquatic ecosystems by alteration of hydrologic regime and fragmentation (Barbarossa et al., 2020). While about 50% of the river around the world is currently changed by dam, this percentage is expected to increase to 93% because of the pending construction of about 3,700 major hydropower dams (Grill et al., 2015).

The construction and operation of dams has extensively altered global freshwater wetland ecosystems, which represent biodiversity hotspots around the world and play a crucial part in protection of biodiversity (Wu et al., 2019). Freshwater wetlands cover about 0.8% of Earth's surface, but host an excessively high diversity of species (Barbarossa et al., 2020). Freshwater wetlands provided habitat for about one fifth of species (particularly the endangered and endemic species) and one third of vertebrate species in the world (Wu et al., 2019).

The aim of this Research Topic is to gather the latest research addressing the critical issue of the impact of construction, operation and removal of dams on biodiversity, with a particular focus on mitigating measures. We are convinced that the studies in this field are an essential condition for biodiversity conservation and ecological restoration in freshwater wetlands. This collection of seven papers is our humble contribution to achieve this target.

To meet energy, water and transportation needs, an incredible amount of dams have been constructed around the world. For example, only in the Yangtze River's watershed of China, over 50,000 dams were built since 1950 (Nilsson et al., 2005; Wu et al., 2019). Dams could contribute to energy and water supply, and flood protection, but they also affect aquatic ecosystems by alteration of hydrologic regime and fragmentation (Barbarossa et al., 2020). While about 50% of the river around the world is currently changed by dam, this percentage is expected to increase to 93% because of the pending construction of about 3,700 major hydropower dams (Grill et al., 2015).

The construction and operation of dams has extensively altered global freshwater wetland ecosystems, which represent biodiversity hotspots around the world and play a crucial part in protection of biodiversity (Wu et al., 2019). Freshwater wetlands cover about 0.8% of Earth's surface, but host an excessively high diversity of species (Barbarossa et al., 2020). Freshwater wetlands provided habitat for about one fifth of species (particularly the endangered and endemic species) and one third of vertebrate species in the world (Wu et al., 2019).

The aim of this Research Topic is to gather the latest research addressing the critical issue of the impact of construction, operation and removal of dams on biodiversity, with a particular focus on mitigating measures. We are convinced that the studies in this field are an essential condition for biodiversity conservation and ecological restoration in freshwater wetlands. This collection of seven papers is our humble contribution to achieve this target.