Mapping and conservation of dry grasslands on the edge of Mediterranean basin – difficult task after changed socio-economic trends M. KALIGARIČ1,2, B. TRČAK3, B. LIPEJ1 & A. SOVINC1 1University of Primorska, Science end Research Centre, Garibaldijeva 18, 6000 Koper, Slovenia.
[email protected] 2University of Maribor, PeF, Biology Dept., Koroška 160, 2000 Maribor, Slovenia. 3 Centre for Cartography of Fauna and Flora, Antoličičeva 1, SI-2204 Miklavž na Dravskem polju, Slovenia Summary Among conservation efforts regarding man-made ecosystems, conservation of dry grasslands on the edge of the Mediterranean basin, represent one of the most difficult challenges. These grasslands, namely, do not suffer so much the desertification, but spontaneous afforestation after abandonment. On the area Kraški rob within the North Adriatic karst, 70 km2 ha has been mapped according to PHYSIS typology. The 15.68 % of the total surface represents grasslands without visible afforestation. But completely changed socio-economic trends in the area (abandonment of agriculture) make keeping the valuable grasslands in good conditions very difficult. An alternative solution was found through activities of the LIFE – Nature project. Mowing and transporting more than 65 tons of hay from the research area to the Lipica stud farm were organized in year 2004 with management prescriptions and plan to arrange a long-term agreement with beneficial effect to grassland biodiversity. Introduction The area of Kraški rob is situated between the Northern Adriatic Sea and Pre-Alpine region in Slovenia and northeastern Italy (Fig. 1). North Adriatic karst represents the northeastern most branch of Dinaric mountains range, extending along the Eastern Adriatic in the Eastern Balkan Peninsula. This karst area is traditionally known as bare, non-forested stony grassland area. This identity of the landscape was formed in the last centuries. The area, which is floristically a contact area between the Mediterranean and Euro-Siberian biogeographical zone, have characteristics of both zones and the natural vegetation is deciduous forest. It could be considered as supraMediterranean belt, constituted by various species of oak (QUEZEL AND MEDAIL, 2003) or subMediterranean belt as we consider it (KALIGARIČ, 1997). The chorological spectrum of the flora of North Adriatic karst could be defined as European s. l. (33%), with euri-Mediterranean (subMediterranean) – Illyrian – Pontic character (Poldini 1989). In lower altitudes Quercus pubescens Willd. and Ostrya carpinifolia Scop. -dominated forests are prevailing. Above 800-1000 m a. s. l. thermophilous basiphilous beech forests are developed. Except rocks and screes, all the nonforested areas are of secondary origin, due to human impact and land use. But due to severe deforestation, starting in Roman times, and reaching the peak in 17th and 18th Century, this area is considered as traditionally scarce populated open landscape. All the area of the North Adriatic karst is under quick overgrowing (spontaneous reforestation) process after abandonment. This process was stressed as negative already by Poldini & Favretto (1986). They calculate for the adjacent Trieste karst the extinction time of karst pastures due to bush encroachment, through a mathematical model. The calculation was made in the year 1986 and extinction should appear in 2013, if no interventions would take place. So we state clearly that re-growth is locally considered as negative process (not being the same in other parts of Mediterranean!). Therefore some measures should be taken to prevent scrub/forest encroachment. This was also one of the goals of LIFE-Nature Project:"Conservation of endangered habitats/species in the future Karst Park". Methods The area The LIFE-Nature granted project is covering tha area of about 7000 ha (see fig. 2) It represent one of the most valuable karst areas within the North Adriaric karst, which include also the “karst
edge”, southern border of the limestone geological bedrock, known by stenoendemic hasmophytic species Moehringia tommasiniana, also target species for conservation within this LIFE project. This LIFE project has also other targets, not elaborated here. Mapping Vegetation was mapped throughout habitat types, according to PHYSIS typology, based on Palearctic classification (DEVILLIERS & DEVILLIERS-TERSCHUREN, 1997). Some types, not present in typology were added. Due to various transitional stages between abandoned fields, abandoned meadows and pastures and scrub and forest, also “hybrids” (transitional forms or mosaic) between 2 or even 3 habitat types were used. Data were elaborated in GIS, using Arc.View 3.2. computer program. Results and Discussion Mapping The map of total habitat mapping is not shown, due to very extend legend (271 types, including all the transitions) and numerous small polygons. In Figure 1 simplified map with only 17 aggregate habitat types is shown. The total 271 types have been aggregated into 17 main groups in order to have better overview on the territory. But for detailed work on small areas, like introducing sheep, mowing plan, agriculture activities, urbanistic plans etc. the detailed typology is useful. The share of grasslands is clearly visible and despite afforestation still considered as high proportion. Today 10,59 km2 are covering with grasslands without visible afforestation signs (scrub and trees). Additional 10,09 km2¸are covered with various kinds of secondary succession series. The percentage of aggregate habitat types is shown in Table 1 and illustrated in Figure 2.
Aggregate habitat type 1. Forest 2. Other woodland 3. Scrubland 4. Riparian willow-ash-elm vegetation 5. Reed-like hydrophillus beds 6. Waters 7. Extensiv humid meadows 8. Extensive dry and semi-dry grassland 9. Tall herb communities 10. Lowland hay meadows and pastures 11. Improved grassland 12. Field crops, fruit orchards and vineyards 13. Screes and rocks 14. Flysch erosion forms 15. Ruderal comminities 16. Developed areas 17. Roads and railways Total:
Area (km2) 29,92 1,87 7,23 0,03
