habitat rupestre.pdf - Società Friulana di Archeologia

FLORA IN THE RAVINES OF MURGECRHIMA-CINP projectis the cas of the Epipactys helleborine, a scarcely strikingOrchis that has been recently reported in the ravine of Alezza(Crispiano): this is the only report in the Tarentine area.Vegetation in ravinesThe cliffs of the ravines are often vertical, with few or novegetation at all. But they host rupicolous entities that haveadapted to live on the rocks, planting their roots in smallcracks in the rocks (chasmophyte) or on modest beds ofdrifts on the rocks.The natural terraces on the ravine cliffs host diversified andlayered vegetation, with the species that need a minimumsoil on the terraces and the chasmophytes on the steep cliffs.Some examples are the Caper (Capparis spinosa) or thebeautiful Apulian Bellflower (Campanula versicolor) which,in Italy, is present only in some areas of Puglia; it is typicalof the Balkans, as the other plants listed above. Also theSouthern Rampion (Asineuma limonifolium) is original fromthe Balkans and the Eastern Mediterranean: it needs littlesoil, and it is often found with the Wild Southern Clove (Dianthussylvestris ssp. garganicus).The ravines are generally oriented on the North-South axis,so the cliffs face East and West. There are also windingbends of the ravine and the diramations some cliffs that canben constantly in semi-darkness; in these cases there aresciafilous species which require air and soil umidity, such asthe Fern and the Rustyback (Ceterach offi cinarum), whosecommon name reminds its favourite habitat, and the rareMediterranean Clubmoss (Selaginella denticulata).The bottom of the ravines is generally a tangle of shrubs andBlackberrys (Rubus ulmifolius), with some Fig tree (Ficuscarica) and the Acanthus (Acanthus mollis e Acanthus spinosus),which inspired the decorations of Corinthian capitals.When the bottom of the ravine is narrow and deep, and especiallyif shadowed, it may contain mesophyll trees, due tothe thermal inversion, such as the Mediterranean Hackberry(Celtis australis), the Elderberry (Sambucus nigra), Hornbeams,Oaks and Ashes.Vegetations of calcareous cliffs and cavesThe calcareous cliffs are an inhospitable habitat, due to thelack of soil and water. The flat surface of rocks is occupiedonly by extremophile lichens (some dozens of different speciesthat need a separated treatment), while the chasmophytescolonize the crackles and the narrow gorges. Theseare small plants with a strong root system; they often have arosette or pad vegetal structure, or they have water reservesin their leaves (as the Starflowers, different species belongingto the Sedum genre).Fig. 9 Garrigue with ferula and asfodeli.volumeRicerca_OK_2012-11-15.indd 186 16/11/2012 15:03:15