The Swedish Wetland Survey : Compiled Excerpts From The National Final Report

• Main Authors: Gunnarsson, Urban, Löfroth, Michael
• Format: Report
• Language: English
• Published: County Administrative Board of Dalarna, Falun 2014
• Subjects: Environmental Sciences; Miljövetenskap; Norway; Northern Sweden; palsa
• Online Access: http://urn.kb.se/resolve?urn=urn:nbn:se:naturvardsverket:diva-9147

The VMI (the Swedish Wetland Survey) was coordinated by the Swedish Environmental Protection Agency in cooperation with the County Administrative Boards during 1981–2005. VMI surveyed all larger wetlands sites outside the Alpine zone. In total, 35, 000 wetland sites were included in the survey, corresponding to 4.3 million hectares, or approximately 10% of the land area of Sweden. The main objectives of the survey were: to classify and identify valuable wetlands which should be conserved for future generations, to investigate the impact of human activities on the wetlands of Sweden, and to increase general knowledge about wetlands in Sweden. In this report we describe the method used, and present some of the main results. In the VMI, wetlands to be surveyed were defined as: ‘areas where the water table, during the main part of the year, is close below, at or above the ground level, including vegetation covered water surface, and areas exposed when the water level is low. Due to limited financial resources a lower size limit was used for selecting sites to be surveyed, i.e. all wetlands larger than 10 hectares in southern Sweden and 50 hectares in northern Sweden. During remote sensing, all sites were classified to wetland type and assigned a nature conservation value. Twelve per cent of the sites were also surveyed in the field, to gather supplementary data. Based on the distribution of different mire types, the country was divided into five mire-type regions (i.e. the Mountain mire region, the Palsa mire region, the Aapa mire region, the Raised bog region, and the Pine bog-marsh mire region). The mire type regions correspond in many ways to the ones in neighboring countries (Finland, Norway and Denmark). The most common wetland type in Sweden is topogenous fens, followed by string mixed mires and string fens. The survey shows that about 80% of the Swedish wetlands are disturbed by human activities, especially by drainage that causes degeneration of the wetland ecosystems. When classifying the site’s nature ...