Year
2016
Abstract
Reintroduced beavers (Castor fiber) can function as ecosystem engineers, offering a natural means of restoring degraded freshwater habitats. This study examined the impact of beaver dam construction on physically degraded headwater streams within a 13-hectare pastureland catchment in eastern Scotland. Through comparison of beaver-modified and unmodified sites, the research assessed whether hydromorphological changes induced by beavers lead to ecological improvements.
Beaver activity resulted in the formation of a series of dam pools, significantly increasing organic matter retention and aquatic plant biomass. Nutrient concentrations—particularly extractable phosphorus and nitrate—were notably lower downstream of beaver dams, suggesting improved nutrient retention, although suspended solids and water colour increased. While local (alpha) diversity of macroinvertebrates was reduced within beaver ponds, the overall (gamma) diversity across the stream landscape was higher due to habitat heterogeneity. Functional shifts in feeding guilds also indicated altered ecosystem processes.
These findings suggest that beaver dam-building can enhance physical complexity and biological diversity at the catchment scale, even in ecologically simplified, agriculturally impacted landscapes. The study supports the potential of beaver reintroductions as a low-intervention restoration tool, though trade-offs related to land use and fisheries require careful management.
Beaver activity resulted in the formation of a series of dam pools, significantly increasing organic matter retention and aquatic plant biomass. Nutrient concentrations—particularly extractable phosphorus and nitrate—were notably lower downstream of beaver dams, suggesting improved nutrient retention, although suspended solids and water colour increased. While local (alpha) diversity of macroinvertebrates was reduced within beaver ponds, the overall (gamma) diversity across the stream landscape was higher due to habitat heterogeneity. Functional shifts in feeding guilds also indicated altered ecosystem processes.
These findings suggest that beaver dam-building can enhance physical complexity and biological diversity at the catchment scale, even in ecologically simplified, agriculturally impacted landscapes. The study supports the potential of beaver reintroductions as a low-intervention restoration tool, though trade-offs related to land use and fisheries require careful management.
Publisher
Freshwater Biology
Source type
Scientific Article