Presentation on theme: "Dominique Richard __________________________________________________________ European Topic Centre on Biological Diversityhttp://biodiversity.eionet.eu.int."— Presentation transcript:
Dominique Richard __________________________________________________________ European Topic Centre on Biological Diversityhttp://biodiversity.eionet.eu.int Ecosystem accounts for grasslands What should we take into account?
Interest in grasslands: several perspectives
Interest on grasslands can be expressed from : - an agronomic perspective, - a general environmental perspective - a more specific biodiversity perspective Combined perspectives are an expression of: - Multifunctionality of grasslands - Goods and services provided by grasslands.
Agronomic perspective Artificial grasslands: almost exclusively with forage leguminosae. Mostly mown. 5 to 10 years Temporary grasslands: mixture of Grasses and Leguminosae. Mown or pastured Permanent grasslands, which include: - Productive permanent grasslands (artificial grasslands more than 10 years old and natural grasslands 1500 UF/year) - Less productive permanent grasslands (alpine meadows, hills, moors and heaths, dry and humid grasslands)
Overall, what do we see ? The environmental problems that are most difficult to solve persist Protecting nature and bio-diversity from land take and use Every day during , about 10 hectares of land (10 football pitches) were taken for motorway construction in the EU built-up area forest land length of road network permanentgrassland
Environmental perspective Erosion: runoff facilitation; mitigation of kinetic impact of rain Depending on practices, improvement of water quality Carbon storage in soils (although counterbalanced by bovine emissions) Landscape
Biodiversity perspective Related habitats are considered in the Habitats Directive: grasslands habitat-types (both in plains and mountains). Several birds-species listed in the Bird Directive depend on dry, mesic and humid grasslands habitats-types. From 1981, the Council of Europe had identified grassland habitats-types as a priority for conservation in Europe, encouraging member countries to include such habitat-types in the network of European Biogenetic Reserves. Grasslands (both humid, dry, mesic) are taken into consideration in action theme 8 of the Pan-European Biological and Landscape Diversity. Dry-grasslands are, with wetlands, forests and agroecosystems among the priority ecosystems taken into consideration at global level by the Convention on Biodiversity.
Some figures showing interest of non-intensively managed grasslands for biodiversity
1080 different species of Butterflies (macro and microlepidoterae) recorded on a 9,5 ha of steppic grassland in Austria (Kasy, 1979) 63 plant species/m2 on the Slovak karst meadow (Slovak National Biodiversity Report) 588 of higher plant species and ferns are recorded - of which 34% are considered as endangered - are recorded in drylands in Germany (Korneck and Sukopp, 1988) (about 3800 species at national level) an acre (4Ha) of old hay meadow can support about 2.25 million spiders. Each spider would consume 2 insects a week for 6 months. Grasslands are dominant habitat-types in 65% of Important Plant Areas in 7 Central and Eastern European countries Grasslands are important reservoirs for Crop Wild Relative of cultivated plants
Out of the 71 most threatened European Butterflies species (on a total of 576 European species), 51 % are linked to grasslands habitats, and more specifically, 34% to dry/mesic grasslands habitats. Source: Council of Europe, Red Data Book on European Butterflies (Rhopalocera) Threatened Butterflies and dry/mesic grasslands
In contrast, wildlife value of intensive agricultural grasslands is very much reduced because of two factors: Few different plant species grow in the field with consequences on wild herbivores limited to those which like eating the intensive grass species. Farming operations such as silaging or intensive and repeated grazing, remove the growing crop from the field in a very short time. Few species can survive this rapid change or alternatively complete their lifecycle within the available period. Ground nesting birds and certain butterfly species are particularly vulnerable. Offwell Woodland & Wildlife Trust
Some examples of possible conflicts/synergies between different goods and services provided by grasslands
Sponging up nitrogen pollution – but losing flowers ‘Calcareous grasslands, one of Britain’s most diverse ecosystems, act as a giant sponge for nitrogen pollution, saving us from some of its damaging effects ‘In experiments we increased nitrogen pollution seven times for seven years, and still more than 70% of it was soaked up. So not much nitrogen is leached into streams or released back into the atmosphere as damaging nitrous oxide. But the cost of this service is lost plant diversity ! ‘Although nitrogen is usually a fertiliser, diverse chalk grasslands need low soil fertility. The extra fertiliser allows just a few grasses and sedges to take over. The more nitrogen pollution falling on the grassland, the greater the impact.’ Biodiversity and Nitrogen (Gareth Phoenix, University of Sheffield)
On the other hand…….
Decreasing nitrate leaching when grasslands are highly diverse (Scherer-Lorenzen et al. 2003, Ecology)Decreasing nitrate leaching when grasslands are highly diverse (Scherer-Lorenzen et al. 2003, Ecology) (Experiments with manipulation of plant diversity Also confirmed by the BIODEPTH experimental project ((Loreau et al. 2001, Science) (BIODiversity and Ecosystem Processes in Terrestrial Herbaceous Ecosystems)(Loreau et al. 2001, Science)
Other ecosystem processes that have been shown to decline with loss of plant diversity in grasslands (BIODEPTH, 2001) Plant productivity - reducing harvest yield, quality and insect herbivore abundance Plant community population changes - reducing the ability of plants to resist weeds and plant diseases Soil invertebrate population changes- crucial for soil chemistry and energy recycling Many of these relationships had generality across all eight of the field sites, exhibiting an effect of biodiversity despite different climate, soil and plant
Conservation strips have significant disadvantages for the farmer: - There is a loss of yield - They are a reservoir of weed seeds to contaminate the adjacent grass crops Conservation strips may need to be mowed or grazed in late summer. By this time a great many species will have benefited from these temporary habitats. The loss of production is minimal when compared to the wildlife benefit! Offwell Woodland & Wildlife Trust
Agricultural system Energetic efficiency versus role in green gaz effects Source: Patrick de Verdière
Ecosystem accounts and evaluation of ecosystem health will have to take into consideration trades off between the different goods and services!
Characterisation of grasslands from various sources
Scoping study on grassland mapping prepared by JRC in collaboration with EEA (2002)
Main points raised: 5 main grassland habitat-types are of interest from various biodiversity analysis (Birdlife, OECD, EUNIS Habitats, Annex I habitat-types) - Dry grasslands - Mesic grasslands, - Seasonally wet and wet grasslands, - Alpine and subalpine grasslands, - Sparsely wooded grasslands. In relation to agricultural issues, a further distinction should be between “improved grasslands” and “extensive grassland and pasture”, which is mostly relevant for mesic grasslands The majority of these grassland types are mapped in CORINE Land Cover type Natural grassland, except that the mesic grasslands are found more in Pastures.
Main points raised: Example for Mediterranean grasslands: Xeric grasslands They show a full phenologic stop during summer and a sort of second spring in autumn when geophytic species bloom. Vegetation development is very early and there is almost no winter vegetation rest. but their reflectance is highly influenced by the ground composition. Another problem is that they can be mixed with recently abandoned crops that are far less interesting. Mesic and wet grasslands Unlike xeric grassland they have their maximum vegetation development in summer thanks to the water presence. They can easily be confused with annual crop, depending on the date of the image. Use of multidate images can be necessary to identify them. Dehesas and other grasslands in sparsely wooded lands Extensive Mediterranean wooded pastures: difficult to make the difference with intensively managed olive tree orchards, for example.
Biopress project (LINKING PAN-EUROPEAN LANDCOVER CHANGE TO PRESSURES ON BIODIVERSITY ) Many lessons to be learned from extensive experience brought within this project In particular use of NATURA 2000 data and CLC data for grassland analysis
Overview on potential data sources on grasslands in Europe Prepared by Jan Plesnik, AOPK/ETC-BD
Apart from Corine land cover 2000 (CLC2000) and NATURA 2000 database UNFCC Land use and land use changes : data on the their extent status and trends have started to be compiled in some European countries within land-use and land-use changes (LILUC) in the framework of the United Nations Framework Convention on Climate Change and its Kyoto Protocol (cf. Watson et al. 2000). CountrySourceYear(s)Note Bulgariawww.veenecol.nl National grassland mapping Czech Republicwww.natura2000.cz National habitat mapping Estoniawww.veenecology.nl National grassland inventory Hungarywww.veenecol.nl National habitat mapping Latviawww.veenecol.nl2003National grassland inventory Lithuaniawww.veenecol.nl National grassland inventory Polandwww.imuz.edu.pl National habitat inventory Romaniawww.veenecol.nl National grassland inventory Slovakiawww.veenecol.nl National grassland inventory Sloveniawww.veenecol.nl2003National grassland inventory Swedenwww.pro-natura.net2001National semi-natural grassland inventories Turkeywww.veenecol.nlUnder preparationNational grassland inventory National grassland inventories
Conclusions For grassland-ecosystem accounts, many issues to take into account (characterisation of grasslands, various ecosystem services and potential trades-off) Several past or on-going projects of high relevance to help defining a methodology (JRC scoping survey, BIOPRESS, BioHAB, MacMan, GREENGRASS, AlterNet..) Some countries (i.e France) interested in launching a national Millenium Ecosystem Assessment. Look for synergy!
Can we consider to organise next year a two-days workshop dedicated to grasslands accounts with experts involved in various aspects of grasslands assessments?