habitat rupestre.pdf - Società Friulana di Archeologia

FLORA IN THE RAVINES OF MURGECRHIMA-CINP projectThe bottom of some ravines (especially the deeper ones, withramifications) is like the underground floor of a building: ithas a different temperature. A thermal inversion occurs,which affects the vegetation composition: the bottom of theravines contains the hill and mountain species. Under thefloristics point of view, ravines can be considered as upsidedown mountains.Fig. 2 Pistacia terebinthus.Fig. 3 Coronilla emerus.Fig. 4 Linum tommasinii.Fig. 5 Cistus salvifolius.The Mediterranean ShrublandThe Mediterranean shrubland characterizes the Murgian tableland:it is a structurally dense and intricated vegetation,with three meters tall sclerophyll bushes (mainly heliophilousand xerophilous species), which resist to soil aridity andlong lasting droughts during the warm Ionian summers.The dominant species on the limestone soils of the lowerMurgia are Mastic (Pistacia lentiscus), Phillyrea (Phillyreala tifolia), Mediterranean Buckthorn (Rhamnus alaternus),Wild Olive (Olea europea var. sylvestris), Prickly Juniper(Juniperus oxycedrus), the rare Phoenician Juniper (Juniperusphoenicea) and Holm Oak in bushes (Quercus ilex).The Aleppo Pine (Pinus halepensis) is not a typical speciesof the shrubland, but since it is a very frugal conifer, it tookroot in the rock cliffs of the ravines, and it adapted to theclimatic and geomorphologic conditions of the area.The higher part of the Murgia has cooler limestone soils:here the Wild Olive is replaced by the Terebinth (Pistaciaterebinthus), the Scorpion Senna (Coronilla emerus), theMyrtle (Mirtus communis), the Strawberry Tree (Arbutusunedo), the Common Hawthorn (Crataegus monogyna), theBlackthorn (Prunus spinosa), tree essences as Oaks (HolmOak, Downy Oak and Macedonian Oak), the Manna Ash(Fraxinus ornus), the Hornbeams (Carpinus horientalis andOstrya carpinifolia), the Maples (Acer monspessulanum eAcer campestre) and other species that give the habitat theaspect of a Mediterranean Forest.The Holm Oak, in its shrubby and tree forms, constitutesevergreen woods. The Downy Oak (Quercus pubescens) isthe main element of deciduous Mediterranean woods of theHigher Murgia. The internal area of the tableland the mitigatingeffects of the sea are reduced. Here, there is a rare speciesof late deciduous Oak, the Macedonian Oak (Quercustrojana), which is from the Balkans and the Aegean area. Itspread in our land when a corridor of land linked the Murgiato the Balkans.The biocenosis of the Mediterranean shrubland is characterizedby scarce herbaceous vegetation, because the evergreentrees and the shrubs keep the underwood in constant semidarkness.The climatic and geomorphologic characteristicsof the land and the intense anthropic activity transformedthe natural vegetation in an agricultural, sylvan and pastorallandscape. In remote times, when the man colonized theMediterranean basin, the practices of cutting trees and burningthe shrubs degraded the vegetation. The shrubland becamesparse, leaving space to the emerging rocks.The GarrigueThe rockiest cliffs are now occupied by the garrigue, vegetationthat represents the degradation of the Mediterraneanshrubland. It was caused by deforestation, fires and intensivepasturage. In this biocenosis, the big bushes of the shrublandvolumeRicerca_OK_2012-11-15.indd 184 16/11/2012 15:03:11