PROJECT DESCRIPTION
BACKGROUND
Karst topography is a landscape shaped by the dissolution of a layer or layers of soluble bedrock, usually carbonate rock such as limestone or dolomite. Slovenia is very rich in karstic landscape. Its intermittent lakes - turloughs - are listed in Annex I of the Habitats Directive and include Cerknica Lake, the largest and one of the most important turloughs in Europe. Cerknica has a flood area that can reach up to 29 km2 in its aquatic phase.
After the wet season, the water drains away through underground caves or sinkholes in the bottom of the lake. In the terrestrial phase, the bottom consists of different habitat types that are favourable for the nesting of endangered bird species listed in Annex II of the Birds Directive and for various amphibians or butterflies.
Steps have been taken historically to either improve the lake’s drainage or flood the lake to suit people’s needs at the time. The numerous interventions have changed the natural water regime, lowering the groundwater level and resulting in a faster drying lake that has negative consequences for aquatic habitats and organisms.
Since 2002 and the creation of the Notranjska Regional Park, the lake has been protected legally. It became a Natura 2000 site and the Park administration has prepared guidelines for its inclusion in the List of Wetlands of International Importance under the Ramsar Convention.
OBJECTIVES
The project aimed to ensure long-term favourable conditions for the conservation of turloughs and other endangered habitat types and associated plant and animal species at Lake Cerknica. It simultaneously sought to promote an even development of local agriculture, forestry, fishing, tourism, recreation and education in accordance with natural values.
An overall Management Plan was to be drafted to tackle the three main threats identified to the habitats: 1. Modified watercourses 2. Abandoning of meadow mowing by local landowners 3. Lack of knowledge of local nature and its conservation.
The main focus was to be restoration of the natural watercourses with the aim of prolonging the drainage time and holding back the water in the driest summer months. This expected to raise the level of groundwater, particularly close to riverbeds or watercourses, crucial for conserving endangered habitat types and species.
The project intended to purchase, remove trees from, mow and mulch abandoned wet grasslands to provide habitat for species such as corn crake (Crex crex). In addition, the beneficiary planned to raise awareness of nature-friendly farming and agricultural policy and highlight the benefits of nature protection for local people.
RESULTS
The Cerknisko Jezero project substantially improved the quality of the Cerknica Lake Natura 2000 site and raised awareness of the site’s importance locally and beyond. It demonstrated new approaches to nature conservation in Slovenia, particularly the purchase of farmland for permanent protection and advanced mowing and mulching techniques on wetlands.
Project partners mapped the lake area to precisely identify the great diversity of habitats present over the 29 km2. This confirmed large areas of tall sedge communities and reed beds, and smaller areas of ten different habitats of Community interest. Another partner provided complementary watercourse mapping and geological probing, which generated topographical maps, watercourse profiles, and the depth and composition of soil along 12 km of filled watercourses.
This vital information enabled the team to draft a Management Plan to guide the project and future watercourse restoration actions. This included a timeframe and financial plan for renaturation of Lake Cerknica watercourses and details on how and where to dig out former meanders. The beneficiary also reviewed the previous 1997 Management Plan and relevant legislation and conservation documents to inform the new Plan.
The project provided the first demonstration of land purchase in accordance with the Nature Conservation Act in Slovenia. It involved preparing extensive documentation, obtaining the necessary permits and consent, and verifying contracts. It managed to purchase 260 ha of land to be set aside for long-term protection of cultural and natural heritage.
Direct action restored 1.35 km of natural streams. This succeeded in raising the groundwater level of the Dujce fen and providing sustenance to characteristic water and river-bank plant communities of the Tresenec stream. Footprints of the elusive otter (Lutra lutra) have been found on its banks.
The project purchased and used an off-road vehicle and specialised tractor for mowing and harvesting hay on 26 ha of flood meadows with low carrying capacity. Mowing was conducted to prevent overgrowth of shrubs towards the centre of the itinerant lake. Furthermore, volunteers cleared coppice from 1.5 ha of the overgrown Dujce fen that was inaccessible to machinery. In 2009 alone, 500 tonnes of hay were mowed and made available to stakeholders.
These actions targeted conservation of specific plants, such as the white beak-sedge (Rhynchospora alba) as well as providing suitable nesting conditions for snipe (Gallinago gallinago) and curlew (Numenius arquata). The actions were carried out in autumn and winter so as to avoid the bird-nesting season.
The project was highly active in engaging the public, including through information notices in a shopping centre, published materials and lakeside boards. It also conducted nature protection actions with a network of schools and held three summer research camps.
Further information on the project can be found in the project's layman report and After-LIFE Conservation Plan (see "Read more" section).