Beaver dams – do they provide ecosystem services?

16 March 2022

A restoration case study called “Beaver re-introduction” is the Swedish contribution to the new EU Green Deal project MERLIN*. The case study will have a before-after design, which means experimental construction as well as removal of 60 beaver dams in Sweden, of which 10 will be located in the Vindeln Catchment including Krycklan (Svartberget Research Station). It is a four-year project and aims to sample two years before the measures (dam construction/removal) and two years of sampling after the measures.

The beaver (Castor fiber), considered a keystone species, recreating new habitats impacting entire landscapes. Photographer: Jörgen Wiklund
The beaver (Castor fiber), considered a keystone species, recreating new habitats impacting entire landscapes. Photographer: Jörgen Wiklund

The studied parameters will be similar in all case studies within the MERLIN project; the focus on beavers as a case study will only be conducted in Sweden. A variety of biota are planned to be sampled as the focus is on biodiversity aspects with elements of potential ecosystem services. Likely parameters to be studied are e.g. fish migration, mitigation of climate change effects (flood and drought resilience, formation of greenhouse gases), methylation of mercury and pathogens (especially Francisella tularensis causing tularemia [Swedish harpest] and Sindbis virus causing Sindbis fever [Swedish Ockelbosjukan] in humans) in beaver systems.

The MERLIN project as a whole is a ‘research and innovation action’ funded under the European Commission’s H2020 programme that involves 44 partners from across Europe, including universities, research institutes, nature conservation organizations, and stakeholders from businesses, governments and municipalities. The involved partners from Sweden are the Swedish Forest Agency (SFA) and SLU, where SFA is responsible for the construction related work and SLU is the scientific partner of the beaver-reintroduction case study. 
Specific questions on the Swedish case study can be directed to Frauke Ecke - contact mail: Frauke.Ecke@slu.se.

MERLIN is an abbreviation for Mainstreaming Ecological Restoration of freshwater-related ecosystems in a Landscape context: INnovation, upscaling and transformation. MERLIN learns from 17 restoration case studies as best-practice demonstrators in terms of innovative restoration measure types, governance and financing frameworks. With investing more than 10 million € in further hands-on upscaling measures.
Find more information on the project´s webpage: https://project-merlin.eu.