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Soil

According to scientific soil inventarisations made, the National Park has a variety of soil types. The main feature of the soil cover in north Velebit, and karst areas in general, is the highly pronounced spatial variability, with a variety of different types of soil found within a small area. The reasons for this include: geomorphologic structure of the terrain, climate, parent bedrock, karstification process, glacial and nivation processes and millennia-long anthropogenic influences.

The main types of soil within the Park are: black soil on limestone, rendzina on dolomite and dolomitized limestone, brown soil on limestone, lessive soil on limestone, brown podzolic soil and acidic brown soil.

Black soil on limestone (Calcomelanosol). Black soils form on hard limestone and dolomites with a calcium carbonate (CaCO3) content of over 98 %. Black soil is a primary development stage on limestone: it occurs under different climate conditions, predominantly in steep mountainous and subalpine regions. The typical pedogenetic processes in the development of calcareous-dolomitic black soil is humus and clay accumulation.

Rendzina on dolomite and dolomitized limestone are formed under different bio-climatic conditions, on substrates with a calcium carbonate (CaCO3) content exceeding 10 % with carbonate regolith produced through mechanical decomposition of bedrock. Rendzina on dolomite is characterized by continuity of soil cover, with depth ranging between 10-40 cm.

Brown soil on limestone and dolomite (Calcocambisol) is formed exclusively on hard and pure limestone and dolomite with less than 1% of undissolved residue. Locally occurring as a source of the mineral part of soil is also a powdery material of aeolian origin. Several theories exist about the genesis of soil on pure and hard limestone and dolomite and their mineral origin, the most accepted theory being the one of insoluble residue from the parent rock. These types of soil are prevalent in the Park.

Lessive soil on limestone (Luvisol) forms on clay substrates or rocks where through disintegration of rocks deeper clay profiles can be created. Luvisols are associated with humid areas where descending water courses may form. A characteristic feature of Luvisol is washing down (lessivage) of clay from the E horizon and its deposition in the Bt horizon. The Eluvial-illuvial migration of clay occurs under mildly acidic conditions (pH 5-6).

Brown podzolic soil (Brunipodzol). In the wider area of Štirovača, silicate soils are found on Triassic clasts: dystric brown soil, Brunipodzol and Podzol. Brunipodzol is an acidic soil with a low base saturation level. The most acidic is the A/E horizon with a 4.3-4.6 pH. One of the characteristic features of Brunisol is its high humus content throughout the profile.

Acidic brown soil (dystric brown soil). Dystric brown soils occur on flint-silicate substrates with a small amount of base cations (sandstones, slates, acidic volcanic soils etc.). The dominant process is weathering (decomposition of primary minerals, clay formation, clay synthesis and iron oxide accumulation). Low substrate base content and intensive leaching in humid climates lead to perceptible acidification and aluminium mobilisation (Al3+).

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