engleski

Soil cover structure on dolomites of North-West Croatia

Soil on dolomites of Samobor and Zumberak hills in north west Croatia were developped as a consequence of interaction of specifie pedogenetic factors. The zoneof triassic dolomites is characterized by higly fracture relief with cone peaks, steep sides and incised valleys. Dolomite parent rock is poorly with shallow and considerably even zone of ohysical dissipation of rocj into dolomite gravel which stipulates the domination of carbonate stony rendzinas on dolomite. On the territory of triassic dolomites of Zumberak and Samobor hills the density of lowlands network is high (5.8 m/1km2) which indicates to the presence of poorly porous parent rock material which stipulated the domination of regular river erosion. Brooks Kupcina and Bregana tributary streams are incised into dolomite body of defile 200-400 m deep penetrating very deep into the highland massif. Remaining mountain crests identical denudation bases heights which indicates to the original existance of one fracture-zone.In spatial distribution of litosequences, the neighbourhood of triassic dolomites is composed of very heterogenous cretaceous flysch, neogenous loesses, lhytotamnial and ereataceous limestone. There four main heterogenous pedocartografic units the soil cover structure: - shallow carbonate stony rendzina, shallow calcocambisol arid lithosls on areas caught by erosion prevail on sunny, steep sides the Querco-Ostryetum carpinifolia forests and its degradation stages ; - carbonate stony medium deep and colluvial rendzina on dolomites, luvisols and calcocambisol prevail on sunny sides under the Lamio Orvale-Fagetum forest in the ground cover structure ; - meadows and land under cultivation on carbonate shallow and medium deep, antropogenized rendzinas and calcocambisols with local findings of terra rossa are located on narrower plains of mountains crests ; - crest stony colluvious dominate in narrow valleys. The most wide-spread pedocartografic units with shallow and medium deep rendzinas, calcocambisols and luvisols occupy steep and very steep slopes. They are mainly grown with forest vegetation and are to lesser extent used as meadows steep slopes of southern expositions are grequently caught by water erosion wich has dich and furrow from. Focus of excessive water errosion 20 years ago was on cca 5 % of dolomite areas. Their locations were prevaling in upper parts of Kupcina on Zumberak were the vegetation devastation was considerably higher due to pasture and felling. Today the antropogenous pressure is much weaker due to dislocation of population and thus the erosion has significantly decreased. Gravel cones on which regosols and rendzinas on gravel have developped were made in areas of eroded slopes. This parent rock material is very suitable for growth of Austrian pine. Rendzinas on dolomitas are, by their mechanical composition, hight clay to fine sandy loam with admixed dolomite stones, pH is weakly alkaline, Ca CO content is changable in a 5 to 50 % range and more. Humus content is from 10 to 15 %. There are porous, shallow and dray soils with thermophylic vegetation on southern clopes and ecologically favourable variant with more humidity occupies sunnier expositions with more mountainous beech forest. Calcocambisol on dolomites in characterized by loamy mechanical compostition, neutral pH medium ecological depth and more favourable production properties than rendzina. Luvisol on dolomites are the leading droduction soil unit. Ecological depth is more that 100 cm acording to texture differentiation they are clay-loams and hight clays, soil reaction is weakly acid and humus accumulative surface horizont under the forest does not surpass 5 or 10 cm.

soils on dplomites; hilly relief; soil cover structure; forest of pubescent oak an flowering ash; beech forest

Naslov na francuskom: La couverture pédologique sur dolomites dans le nord-ouest de la Croatie