Beaver reintroductions

Overview

After 400 years of absence, beavers were re-introduced in the UK The re-introduction of beavers lead to an overall improvement in biodiversity, water quality and food prevention The Biodiversity Quality Calculator was used to assess impacts of beavers on biodiversity

Project brief

Nearly hunted to extinction in Europe Re-introduced in the UK in 2011 Creates habitat by building beaver dams and lodges Species is considered as ‘ecosystem engineer’

YEAR

2015

SOLUTION RESULTS

manage Biodiversity

An increase in species richness and biomass in the indicator groups.

Protect Habitats

An ecosystem with more variation in habitat structure.

empower-us-to-act People

Improvements in water quality and flood prevention, which could influence future management plans.

How we added value.

Habitat Survey & Design: Beaver enclosures

Before the re-introduction of beavers, the land near Okehampton was characterized by an area of dense willow scrub growing around a simple channel. A few years later, land within the beaver enclosure looks completely different: A mosaic of pools, shrub, dead wood and culm grassland is covered with colourful insects and flourishing wetland plants.

Biodiversity Valuation: the Biodiversity Quality Calculator

The Biodiversity Quality Calculator is developed by Dr. Alan Feest of Ecosulis. The calculator provides quantitative outputs based on a variety of biodiversity indices that are generated from biodiversity measurements and sampling efforts on the site.

Result: Biodiversity increase

Bryophytes (non-vascular plants like mosses), bats and aquatic invertebrates were used as indicator groups, as these species are most associated with beavers. In all these groups the number of species and the species biomass increased as a result of beaver introductions. Also, dominant species became less abundant, leaving space for rare species to enter the habitat.

Result: Change in nutrients

The pools that beavers create also act as nutrient sinks, in particularly for nitrogen. This was concluded after researchers discovered an increase in nutrient intolerant bryophyte species (non-vascular plants like mosses), that started to appear in the beaver enclosure. 

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