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Chapter 1 History of La Crau Creation of the Natural Reserve of La Crau: implications for the creation and management of protected areas. 1* 2Elise Buisson and Thierry Dutoit 1 Institute of Mediterranean Ecology and Paleoecology, UMR/CNRS 6116 University P. Cézanne, FST Saint Jérôme, case 462 13397 Marseille Cedex 20 France 2 UMR INRA-UAPV 406, Écologie des Invertébrés Site Agroparc 84914 Avignon France Article accepted in Journal of Environmental Management on August th26 2005. Abstract Grasslands were once widespread and species-rich ecosystems, they have drastically decreased throughout the world, largely due to changes in land-uses. Remnant grasslands are often highly degraded and disconnected and require active conservation. In order for grasslands to be maintained worldwide, protected areas need to be created. While adequately creating and managing protected areas has proven difficult, this can be improved by following a three-point guideline: 1) consider many ecological groups (birds, insects, plants); 2) use conservation biology knowledge; 3) seek agreements with concerned parties by comprehending elements of economy, politics and sociology. Based on the example of La Crau, a steppe area in South-eastern France, this review aims at i) illustrating that this guideline can facilitate creating and managing protected areas and ii) proposing improvement to the guideline while keeping it simple. In La Crau, the need for ...
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| Publié par | Zawyug |
| Nombre de lectures | 22 |
| Langue | English |
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Chapter 1 History of La Crau Creation of the Natural Reserve of La Crau: implications for the creation and management of protected areas. Elise Buisson 1* and Thierry Dutoit 2 1 Institute of Mediterranean Ecology and Paleoecology, UMR/CNRS 6116 University P. Cézanne, FST Saint Jérôme, case 462 13397 Marseille Cedex 20 France 2 UMR INRA-UAPV 406, Écologie des Invertébrés Site Agroparc 84914 Avignon France Article accepted in Journal of Environmental Management on Au u 26 th 2005. gst Abstract Grasslands were once widespread and species-rich ecosystems, they have drastically decreased throughout the world, largely due to changes in land-uses. Remnant grasslands are often highly degraded and disconnected and require active conservation. In order for grasslands to be maintained worldwide, protected areas need to be created. While adequately creating and managing protected areas has proven difficult, this can be improved by following a three-point guideline: 1) consider many ecological groups (birds, insects, plants); 2) use conservation biology knowledge; 3) seek agreements with concerned parties by comprehending elements of economy, politics and sociology. Based on the example of La Crau, a steppe area in South-eastern France, this review aims at i) illustrating that this guideline can facilitate creating and managing protected areas and ii) proposing improvement to the guideline while keeping it simple. In La Crau, the need for conservation was first acknowledged in 1975. Between 1983, when a request for a protection decree and 1990, when the first concrete protection measure was taken, 20% of the steppe disappeared. It took another eight years to reach a concerted management plan in 1998. The review shows how using ecological guidelines would have helped better and faster protection of the steppe. Improvements to the guideline drawn from La Crau experience include: the protection of some 35
traditional practices; the protection of some degraded habitats that can substitute for habitats that no longer exist; the restoration of degraded habitats that do not qualify for protection; and the flexibility of the management plan. Keywords : grassland, management plan, protection, traditional practices. Introduction Grasslands were once widespread (Henwood, 1998) and species-rich habitats, they have drastically decreased throughout the world (Jacobs et al., 1999), due to housing and industrial development, agricultural intensification, changes in agricultural practices and changes in fire regimes. Degradation and fragmentation have also reduced grassland habitat quality by increased crowding effects, edge effects, number and diversity of neighboring habitats as well as by the loss or decrease of endemic species (Saunders et al., 1991; Harrison and Bruna, 1999). According to the 1993 United Nation List of National Parks and Protected Areas, only 0.69% of temperate grasslands and 6.35% of tropical grasslands and savannas are protected in the world (IUCN, 1994). Protection of grasslands, and particularly temperate grasslands, should be increased to levels compatible with their durability (Henwood, 1998). New protected areas should thus be created along with adaptative management plans. Areas already benefiting from protection statuses should see their management re-planned in order to take conceptual advances into account (Phillips, 2003). In order to create and maintain protected areas, conservation theory advocates 1) to take into account the requirements of a range of ecological groups (e.g. plants, birds, insects); 2) to use practical knowledge in protected area design (size, shape, dynamics, buffers) and spatial heterogeneity (fragmentation, neighboring habitats); and 3) to seek agreements with concerned parties (Wilshusen et al. 2002) by comprehending elements of economy, politics and sociology. Using local knowledge and integrating traditional practices is particularly important to take into account in grassland conservation since many grasslands reflect centuries of interaction between nature and traditional land-uses, such as grazing or hay cutting in Europe (Bignal and McCracken, 2000; Pienkowski, 2004), and fire and hunting in America and Australia (Pyne, 1995). While basic requirements are known, adequately designing and managing protected areas has proven more difficult than designating them. In this review, we use the example of La Crau to illustrate the need for meeting these requirements from the initial creation of protected areas and, the consequences of not doing so. Although this steppe has a unique plant community and some endemic species, it is a relevant case study because it is representative of semi-arid/Mediterranean herbaceous/steppe formations in Europe (55 500 km²), in continental Asia (726 700 km²), in Africa (335 400 km²), in the US (43 900 km²), and in Australia (657 600 km²) (Demangeot, 1996). Moreover, La Crau is an 36
endangered ecosystem where conflicts for land-uses have constantly existed, as it is often the case in areas to be protected. We also looked into improving simply the ecological guidelines using interesting results drawn from La Crau experience. La Crau: a site of great biological importance Description of La Crau The plain of La Crau located in south-eastern France (Provence) (Fig.7) was called "campus lapideus" by Romans or “monotonous and uninteres ied and thus poortliyn gkno(wVne rabny , e1c8ol0o5g; isJtas cqaunedm inn,a tu1r8a3li5s)t.s Itu nrteil mtahien eladt eu n1s9t t u h dcentury. However, it is a site of great biological importance (Devaux et al., 1983) which has been shaped over centuries by a dry and windy Mediterranean climate and has evolved with particular soil conditions (Fig.8) and with 2000 to 3000 years of itinerant sheep grazing (Badan et al., 1995) (Fig.9). Figure 7. The plain of La Crau, 60 000 ha, is located in South-eastern France. Ancient delta of the Durance River, it is bordered to the north by a mountain range (Alpilles), to the south by the Mediterranean sea, to the east by the Etang de Berre (Berre Lagoon), and to the west by the Rhone Delta.
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Figure 8. Silicaceous stones, which cover about 50% of the ground in the steppe, create a microclimate, where temperature recorded in summer reached over 60°C above the stones and only 30°C below (photo by Fabre & Pluvinage 1998). The average soil depth is 40 cm overlying a 5 to 25 meter thick layer of impermeable conglomerate making the alluvial water table inaccessible to the roots of plants. Figure 9. Steppe of La Crau in spring. Grosse-du-levant sheepfold land - May 1996 (Fabre & Pluvinage 1998).
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Vegetation The first thorough botanical inventories were carried out in 1950 (Molinier and Tallon, 1950) and four main plant communities were described: Asphodeletum fistulosi in the very center of the plain; Quercetum ilicis at the edge; Quercetum cocciferrae closer to cities; and Brachypodietum phoenicoidis on abandoned land and along roads. Three other plant communities containing ruderal species were also found in the center of the plain, encircling around sheepfolds (Molinier and Tallon, 1950; Devaux et al., 1983; Gomila, 1987; Loisel et al., 1990). The steppe composed of species like Asphodelus ayardii (onionweed), Brachypodium retusum (ramified falsebrome), Thymus vulgaris (thyme), Stipa capillata (feather grass) and Linum gallicum (flax) was given little attention by Molinier and Tallon. It was described as quite homogeneous, except for patches of a few square meters maximum called Crassuletum tillaeae, where vegetation is even lower than that of the steppe (discussed by Loisel, 1976). Rieux et al. (1977) later described these patches as unique and characteristic of La Crau. They are composed of phanerogams (reproducing by seeds, 33%) and cryptogams (reproducing by spores, 67%): cyanobacterias (not taken into account for %), squamulose and crustose lichens (43%), liverworts (14%), mosses (10%), and Crassula tillaea (mossy stonecrop). It is not until 1983 that the vegetation was described more precisely as composed of 0% of woody plants > 50 cm and 49.4% of annuals mainly germinating in autumn, spending winter as seedlings, growing in the spring and flowering from March to May or in September (Bourrelly et al., 1983). Most of the biomass is produced in spring and autumn. The primary productivity of the vegetation steppe was assessed to 2.1 tons of DryMatter/ha/year, similar to other steppe formations (e.g. in Sahel, Africa). Amongst the 113 plant species found in the steppe (Bourrelly et al., 1983), Brachypodium retusum represents 50% of the herbaceous biomass and none is listed on the regional, national or European red list as endangered or threatened (Conservatoire Botanique National de Nancy, 1982; World Conservation Monitoring Center, 1997). However, the floristic composition and structure of the steppe is uncommon (Devaux et al., 1983) compared to other B. retusum communities, which include Rosmarinus officinalis (rosemary) or Smilax aspera (Italian sarsaparilla) (Bourrelly et al., 1983). A haven for birds, reptiles and insects The steppe is haven to several interesting birds (Cheylan et al., 1983; Olioso et al., 1983): the only French population of breeding Pterocles alchata (pin-tailed sandgrouse; Cheylan 1975), the largest French population of Tetrax tetrax (little bustard; Jolivet, 1997) and one of the two French populations of the globally threatened Falco naumanni (lesser kestrel). Prior to 1965, one unpublished report was written on P. alchata (Verdot, 1827). The first major ornithological studies were published in 1965 and 1975: one on the 39
behavior of four birds (Frisch, 1965) and one listing all vertebrates (29) and their density (Cheylan, 1975). Amongst the 11 vertebrate species listed as breeding in the steppe and not settled on the steppe in some human-created structure, all were birds. La Crau is thus more similar to arid ecosystems formed by a combination of eolian and fluvial erosion populated by birds (desertic regs and hamadas), than to those formed by eolian deposition and populated by reptilians and mammals (ergs). The steppe provided a haven for the largest population of Lacerta lepida (jeweled lizard) in France until 1990. Within ten years, this species has become extremely rare. It may be because of an epidemic or the use of toxic treatments on cultivation or sheep flocks (Cheylan and Grillet, 2003), but no studies have been carried out to determine the cause. The steppe also provided a haven for arthropod 54% of which are Mediterranean species (Bigot et al., 1983; Leonide, 1983), for an endemic apterous grasshopper, Prionotropis hystrix rhodanica (hedgehog grasshopper) (Foucart and Lecoq, 1998) and for an endemic Coleoptera, Acmaeoderella perroti (Crau jewel beetle) (Ponel and Braud, pers.com.). Traditional land-use Sheep grazing has been the traditional land-use for several centuries (Masson and Estrangin, 1928; Long and Pradon, 1948) and is the only d to ensure the o e steppe. In tvheeg e1t6a th ti ocne ntmuaryn acgaenamles nwt earde vboucilatt teo irrigate 15 000 hdeurctaabrileitsy of f sttheppe with the rich and silty water of the Durance river (Masson and Estrangin, 1928). Irrigated hay production is now one of the main economic activities of the area as the warm and sunny climate allows four hay cuttings every year, two of rwothiacteh fhraovme ah aqyu afliietlyd lsa b(e4l t h ( Fciugt ti1n0g).) Iinn thaeu tpulaminn , tfolo tchkes osft eAprlpees iMn esripnrionsg ,s hweiethp transhumance by trucks to the Alps for the summer (Fabre, 1998; Fabre and Boutin, 2002). The impact of sheep on steppe vegetation was first studied in 1986 (Cherel, 1986) and showed that sheep mainly feed on poaceae, particularly B. retusum in the spring, but prefer dicotyledons, which they feed on selectively. Abandoned arable fields, and alfalfa or Italian ray-grass pastures are valuable for grazing because their vegetation complements that of the steppe (Adama, 1994; Dureau and Bonnefon, 1998). Main Threats h Before the 20 t century, the steppe had been explored by shepherds and only a few geographers and naturalists (Veran, 1805; De Villeneuve-Bargemont, 1821; Jacquemin, 1835; Castagne, 1862; Fourreau, 1868; Roux, 1881; Blanc, 1897 unpublished). It was not until the 1950s that biologists started to study La Crau (Molinier and Tallon, 1950). Even then, although the steppe was found to be unique, Molinier and Tallon (1950) did not advise its
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protection. They concluded, probably out of simple pragmatism just a few years after WWII, that the steppe could be cultivated if necessary.
Figure 10. Map of land-uses in the Special Protection Area (SPA) plain in 1998. The biggest patch of steppe covers 6500 ha. Industry started to encroach on the steppe early (Deverre, 1996; Etienne et al., 1998), leaving less than 30 000 ha of open grassland by 1930. From the 1960s to the mid 1980s, melon was cultivated in part of the remaining central patch of steppe (Borrey, 1965). The extent of the impacts that this cultivation had on the steppe ecosystem was not properly assessed at the time because, 1. melon cultivation was unauthorized and thus not monitored and 2. because cultivated plots were moved every year (Buisson and Dutoit, 2004). We now know that the steppe may never recover from such a disturbance (Devaux et al., 1983; Masip, 1991; Borck, 1998). Cheylan (1975) was one of the first authors to notice and write about how the steppe of La Crau is unique in France, that it provides a haven for the encroachment of acegrritcaiunlt ubrier,d inpdoupsutlrayti, oqnus,a rarineds haansd bmeileitna rtyh raecattievintieeds . bAy t the start of the 21 st century, there are only 11 500 ha of steppe left, fragmented into several patches (Deverre, 1996, Gaignard, 2003) (Fig. 10). Fragmentation has isolated grasshopper populations (Foucart and Lecoq, 1998) and has caused local extinction like that of Otis tarda (great bustard) last observed in 1969 (Hovette, 1972).
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The main types of protected areas in France and the case of La Crau Various tools can be used to designate protected areas in France. 1) Reserves on public land are designated by the préfet (state representative) applying French law (loi n°76-629 du 10 juillet 1976, article L.242-1) at the request of associations, NGO or private foundations. Regulation on the 457 reserves (more than 7090 km²) is strict and access is often forbidden. The R éserve Naturelles des coussouls de La Crau created in 2001 covers 7412 ha and is one of the largest in France. 2) Reserves on private land (140 réserves naturelles volontaires ) are also designated by the préfet applying French law (article R.242-26 circulaire n° 87-87 du 2 novembre 1987) at the owner request. 3) There are seven parcs nationaux (national parks; 12 800 km²) designated by the Council of State applying French law (loi du 22 juillet 1960, L.241-1). They are composed of a strictly regulated core area dedicated to conservation and recreation and of a buffer zone where cultural, social and economical development is encouraged (Parcs Nationaux, 2005). 4) Le Conservatoire du littoral (Coastal protection agency) ensures the definitive protection of outstanding natural coastal areas (loi du 3 janvier 1986) by acquiring land through private agreement or consultation with communes (the smallest administrative unit). Management of the 500 sites (705 km²) is entrusted to local authorities or appropriate organizations. 5) There are 44 Parcs Naturels Régionaux (69 668 km²) designated by corresponding région (~state parks) with the consent of concerned départements (~counties) and communes. Contrary to national parks, state parks all have a different charter that defines their goals. These parks are interesting because they are cultural landscapes, the result of man's interaction with nature over the centuries and are thus maintained through traditional methods of cultivation (FPNR, 2005). 6) There are 467 Arrêtés préfectoraux de protection de biotope (2100 km²) designated by the préfet applying French law (decret n°77-1295 du 25 novembre 1977 and loi n°76-629 du 10 juillet 1976, article R.211.12) to protect the habitat of protected and listed species. To designate protected areas, France can also use various European Union directives; they are texts ratified by all state members which plan objectives with an obligation of results, leaving each country free of using their own legal means to reach them. Special Protection Area (SPA) are created applying a E.U. directive requiring the protection of wild birds (79/409/EEC, 1p9ot7e9n).ti aTl hem aDneapgaertmmeennt t iso f pElacnoleodg yl oocfa lelya c(hF rcaonucnet:r y1 0d3e siSgPnAa;t e~ t8h0e0s0e karme 2 as and ). The SPA Crau sèche was designated in 1990 and covers 11816 ha. Special Conservation Area (SCA) are designated applying annex II (animal and plant species of community interest) of the E.U. directive requiring the protection of natural habitats (92/43/EEC, 1992). Annex I plans for the establishment of a consistent network of SCA within which SPAs are automatically integrated: NATURA 2000. The SCA Crau centrale - Crau sèche was designated in 1996 42
and covers 31458 ha. LIFE programs are a E.U. financial instrument for the environment specifically allocated to fund NATURA 2000. Conservation Plans First proposal: a failure to communicate In 1979, the French Department of the Environment developed a research program to assess the state of the steppe and to propose a management plan to conserve it. Following this program, researchers proposed that some remnant patches of steppe in the North, where P. alchata winters, and the largest remnant patch in the center be conserved along with a management plan (Bourrelly et al., 1983; Bigot et al., 1983; Cheylan et al., 1983; Devaux et al.,1983; Leonide, 1983; Meyer, 1983; Olioso et al., 1983). The plan proposed that these two areas be conserved by restricting the introduction of plants and animals aimed at improving cynegetic potential, stopping cultivation, prohibiting stone removal and irrigation, restricting vehicle access and quarrying, and maintaining grazing at the same rate (2 sheep/ha of steppe) (Meyer, 1983). This proposal was ignored until 1987, when a protection decree was requested by ornithologists and conservationists concerned with the steppe ecosystem, who did not consult stakeholders (breeders, shepherds, hay producers, tree growers, quarry owners, the military, etc.) before hand. Although the request was rejected, this led to misunderstandings and resentment between the parties (Deverre, 1996). From 1988 on, nature protection NGOs worked at dissolving some of the farmers' traditional suspicion of conservationists and biologists along with the misunderstanding created in 1987 and at improving communication between stakeholders (Cheylan et al., 1990). An information center was opened in 1989 with the help of the city of Saint Martin de Crau and the German NGO Stiftung Europäisches Naturerbe. Second proposal: conservation of steppe and surrounding habitats In 1990, France designated an 11 816 ha portion of the steppe as a E.U. Special Protection Area (SPA) (Fig. 11). A LIFE program helped conservation agencies and interested sheep breeders to buy patches of the steppe located in the SPA. This program in which most stakeholders took part and which helped more than 13 breeders to acquire ~2800 ha of land, allowed the beginning of a reconciliation between parties. This was also the start of working towards common aims. Protection measures helped conserve the steppe in the SPA. However, this conservation was found to be fragile and precarious, especially because of the fragmentation of the remnant patches of steppe (which led to a loss of bird and invertebrate populations). Therefore, a research program initiated by Conservatoire-Etudes des Ecosystèmes de Provence (CEEP 43
association for nature conservation in Provence) in 1994 was sponsored by the E.U. Results published in 1998 helped planning better management, on a larger scale and involving most stakeholders and users in the steppe.
Figure 11. Limits of the three protection areas in La Crau. The SCA (Special Conservation area) part of the European Natura 2000 network includes the SPA (Special Protection Area), the Réserve Naturelle as well as complementary habitats. The 11 816 ha SPA (mainly steppe habitat) was created in 1990 applying the 1979 E.U. Birds Directive. The 31 458 ha SCA (complementary habitats) was created at the end of the 1990s applying the 1992 E.U. Habitat Directive. The Natura 2000 network is applied in La Crau since 1999 and the local steering committee is the hay producers. The 7412 ha Réserve Naturelle des Coussouls de Crau was created in 2001 and benefits from a high degree of protection. The 1998 study concluded 1) that large patches of steppe are necessary for steppe bird species, such as Pterocles alchata, Tetrax tetrax, Burhinus oedicnemus (thick-knees stone curlew), and Falco naumanni to survive; and 2) that some species seem to benefit from various habitats, such as surrounding cereal fields, abandoned fields and hay fields with their hedgerows, which complement or supplement each other, for animal species to complete their life cycle of feeding, roosting and breeding (Vivat, 1998; Wolff, 1998; Brotons et al. 2005). Even within the steppe, the various steppe patches are grazed by different sheep herds, which creates a spatial heterogeneity of vegetation which is attractive to birds (Fabre, 1997; Dureau, 1998; Wolff, 1998). 44
The 1998 study also concluded that 1) keeping shepherds as a key group is important because large flocks are profitable for breeders and they require shepherds to look after them (Dureau and Bonnefon, 1998); and 2) that surrounding habitats are valuable for today's itinerant sheep grazing: breeders need their flocks to graze the fourth hay cutting in autumn because steppe vegetation is dry; hay producers need the flocks to graze on hay fields in order to fertilize them (dung and urine) and to make a profit on this fourth hay cutting. Because of their close connection, both traditional hay production and extensive sheep grazing were helped through agri-environmental measures based on article 19 of 797/85/EEC (agri-environmental measures are payments made to farmers to continue particular practices considered necessary and of value from an ecological perspective). Third proposal: spatial heterogeneity Since a mosaic landscape where diversified habitats co-exist (steppe and extensive agriculture) seemed to be essential to some species, the French Department of Environment has thus sponsored a research program ("Espaces Protégés" 2001-2004) to assess all positive and negative effects of fragmentation on the functioning of the remaining patches of steppe, and to integrate results into a new stakeholder and user-inclusive landscape conservation plan. A second LIFE research program has also been sponsored by the E.U. and the French Department of Environment (1997-2001) in order to plan better management for Falco naumanni . The 2001 study confirmed by a detailed large-scale vegetation study that the impacts of melon cultivation and of fragmentation are extremely high and persistent (Buisson and Dutoit, 2004; Römermann et al., 2005). It also showed that the resilience of Messor harvesting ants and Coleoptera is reduced because primarily dependent on plant species richness and plant composition (Fadda, 2002; Fadda, 2003). The impacts of fragmentation on P. h. rhodanica were hard to evaluate since there were only two populations left, 12 km apart. However, a genetic study clarified its taxonomic status and confirmed its degree of protection. Its danger of extinction is linked to its reduced habitat and not to its genetic diversity ( Streiff et al., 2002 ). The development of protection measures for extensive agricultural plots and abandoned fields is strongly advocated (Wolff et al., 2002). It is also recommended that the large patch of steppe remain intact and grazing be conserved, that extensive agriculture be stopped from spreading and that industrial sites and orchards be restored (Pilard and Brun, 2001 unpublished; Wolff et al., 2002). Indeed, the 2001 study have confirmed 1998 results showing that extensive agricultural plots, hay fields and abandoned fields are valuable to some species, such as P. alchata, B. oedicnemus, T. tetrax, F. naumanii and Anthus campestris (tawny pipit) (Pilard and Brun, 2001 unpublished; Wolff, 2001; Wolff et al., 2001). Some other birds, such as Alauda arvensis (skylark) and Calandrella brachydactyla (short-toed lark) seem indifferent to these habitats but are clearly influenced negatively by 45
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