The application of the Shorezone Functionality index on Italian, Austrian and Slovenian lakes within the SILMAS project International working group Maurizio Siligardi, Barbara Zennaro (Agenzia provinciale per la protezione dell’ambiente) Rossano Bolpagni (università di Parma, Regione Lombardia) Roswitha Fresner, Michael Schönhuber (Carinthian Institute for Lake Research) Liselotte Schulz (Government of Carinthia, Dep. 8 – Environment) Tina Leskosek (National Institute of Biology, Slovenia) Coordination Maurizio Siligardi, Barbara Zennaro (Agenzia provinciale per la protezione dell’ambiente). Authors Maurizio Siligardi, Barbara Zennaro (Agenzia provinciale per la protezione dell’ambiente). Rossano Bolpagni (Università di Parma, Regione Lombardia) Michael Schönhuber (Carinthian Institute for Lake Research) Tina Leskosek, Irena Bertoncelj, Uros Zibrat, (National Institute of Biology, Slovenia) Acknowledgement Special thanks from APPA to all those that hosted and participated to the SFI trainings during summer 2012 and all those that supported the working group to carry on the work. APPA non è responsabile per l’uso che può essere fatto delle informazioni contenute in questo documento. La riproduzione è autorizzata citando la fonte. 2 Summary 1. The SILMAS project.................................................................................................................... 4 2. The importance of the lake shorezone ............................................................................... 6 3. The Shorezone Functionality Index ..................................................................................... 8 4. The Shorezone Functionality Index as a management tool ........................................ 12 5. The application within the SILMAS European Project ................................................... 14 6. SILMAS Lake Reports .............................................................................................................. 16 Levico Lake .......................................................................................................................... 17 Caldonazzo Lake ................................................................................................................. 21 Idro Lake .............................................................................................................................. 26 Wörthersee ........................................................................................................................... 28 Millstätter See ...................................................................................................................... 31 Lake Bohinj .......................................................................................................................... 34 3 1. The SILMAS project 4 The Alpine lakes share a common identity, rooted in their geographical location and the cultural and economic benefits they generate. Given how difficult it is to reconcile environmental protection and human activity, lake managers (elected representatives, government bodies and local associations) decided to pool their experience to solve the problems they all faced. To this end, five countries - France, Italy, Slovenia, Germany and Austria (figure 1) - formed a network of Alpine lakes. Launched for a three-year period (2009/2012) as part of European territorial cooperation, SILMAS (Sustainable Instruments for Lake Management in the Alpine Space) is a major project aimed at pooling experience and know-how in sustainable Alpine lake management. SILMAS follows on from Alplakes, an earlier network of Alpine lakes. SILMAS objectives are • Share ideas and experience across a European network • Produce concrete tools (technical guides, training programmes, educational games) to help Alpine lake managers protect their resources • Raise public awareness of the need to protect and sustainably manage this fragile environment SILMAS work priorities are • The probable effects of climate change on the Alpine lakes, and how to tackle them • Managing water usage conflicts • Educating the public in sustainable development as it relates to the Alpine lakes Figure 1> Countries participating to the SILMAS project. 5 2. The importance of the lake shorezone 6 While most of earlier indices were characterized by a particular analysis, for example to the water itself (chemical analyses) or to the biotic environment (biological extended index), the lake Shorezone Functionality Index (SFI) looks at the overall status of the lacustral environment and assists in the identification of the causes of deterioration, zooming out from the waterbody itself to also include all the surrounding territory and watershed topography. The area around the shores is a transition zone (ecotone) By “shorezone”, it is meant that area that includes the littoral between the surrounding territory and the lake and guarantees (maximum depth of 1 meter) and the riparian zones, and it the execution of the ecological processes needed to protect extends inland up to 50 meters from the shoreline (with the the lake from the wateshed’s no-point sources of pollution. Its exception of interruptions or particular lake morphology which structure and the extension are influenced by the topography, may limit its width) (figure 2). the climate and the soil’s geological composition, while its water fluxes, the nutrients and sediment inputs, and the diffusion of animal and plant species are influenced by the lake riparian vegetation. Figure 2> Structure of the lake shorezone. The riparian zone, the area immediately adjacent to a body An healthy littoral zone (the first meters from the shoreline into of water functioning as a transition between the lake and the the water) also provides habitat, food and nesting materials for surrounding territory, is important as it regulates inputs (nutrients aquatic and terrestrial animals, it is important for nutrient cycling and sediments), improving the lake water quality by filtering the and also protects the shoreline from erosion, favoring a good runoff from the catchment area and removing pollutants (the water clarity (through reduced wave action). vegetation in the riparian zone can remove up to 90% of the By “Lake Shorezone Functionality” it is meant the capacity to nutrients passing through) and by aiding sedimentation (the accomplish those determinate functions. vegetation slows the water flowing into the lake); it also provides habitat to aquatic and terrestrial animals, including food, shade (temperature control), shelters, areas for hunting and breeding; moreover it protects the shoreline from erosion, favoring the bank stabilization. 7 3. The Shorezone Functionality Index 8 The importance of understanding and evaluating the lake shorezone functionality lead to the creation of a new system of indicators that could evaluate the shorezone functionality. The Shorezone Functionality Index was developed in Italy in 2004 by the National Environmental Protection Agency (APAT, now ISPRA)’s working group, coordinated by the Provincial Environmental Protection Agency (APPA) of Trento. It was created as the twin brother of the already existing Fluvial Functionality Index (2000) and tailored to the reality of the Alpine lakes. It was later integrated within the AlpLakes European Project for shore that has similar ecological, morphological and functional the lakes in region Lombardy (Italy), within the Silmas European characteristics and can be therefore described in a single form. project for the lakes along the alpine arch (Italy, Austria and Every time there is a change in one or more parameters (for Slovenia), within the Eulakes European Project modified for the example artificialization, shore zone width or composition), a big lakes of central Europe (Italy, Austria, Poland and Hungary) new form is used to describe the next homogeneous shorezone and finally ran in the lakes of by Aracaunia (Chile), by the stretch. University of Villarica, for the Chilean Environmental Agency. Different parameters are surveyed and evaluated in the field with Both biotic and abiotic factors are used to evaluate the buffering an ecological point of view. They include ecological parameters capacity of riparian vegetation, the complexity and artificiality of (typology, width, continuity or interruption of the riparian the shoreline, the anthropogenic use of the surrounding territory, vegetation), socio-economic parameters (land use, presence and the way the inputs enter the water body from the watershed. of infrastructure…) and other general parameters (steepness, concaveness, shore artificiality…). The SFI application consists in filling out two forms: the first form collects general information about the lake and its watershed Each surveyed parameter has its own numeric weight, and a (topography, morphology, climate…); the second form is filled dedicated software (SFINX02) runs the parameter collected out for each homogeneous shorezone stretch identified in the for each homogeneous stretch through a classification tree field. The “homogeneous shorezone stretch” is a stretch of (figure 3) that will lead to different functionality levels. 9 visuel italien Figure 3> The classification tree in the SFI software. 10 During the phase of the index development, nine parameters were identified, through a neural network analysis, as the ones influencing the most the shore functionality (figure 4). There parameters are: • Shore artificiality • Presence of grass • Interruption of the lake-shore-zone