Characteristics and ecological-productive potential of the serpentine soils in Forest Economic Area “Donja Velika Usora”

Abstract

The paper analyzes characteristics of soils on serpentinite in order to define their ecologicalproductive potential as a basis for forest ecosystems sustainable management оf Teslić’s forest- economic area. Ultrabasic parent material occupies significant area of the inner Dinarides, known as the Bosnian serpentine zone and has specific features that reflect on the soil. The terrain consists of sharp reefs and very steep slopes. The area has a typical moderate continental climate, with an average annual air temperature 9.8 °C. The average rainfall is 1026 mm, with a maximum in June (120 mm), and the minimum in January (65 mm). Water deficit in soil occurs during the summer months. Vegetation cover is presented with oak and hornbeam forests (Querco-Carpinetum Fuk. et Stef. 1958), basiphilous pine forests (Erico-Pinetum silvestris nigrae serpentinicum Fuk. et Stef. 1958) and beech-fir forests (Abieti-Fagetum Fuk. et Stef. 1958). The six soil profiles were opened in sections 01, 02 and 03 of the Economic Unit “Donja Velika Usora” at different exposures. External and internal soil morphology was explored in each profile, with the separation of basic genetic soil horizons. According to National soil classification system (Škorić et al., 1985), three soil types are determined:

- Ranker, subtype eutric, variety brownised-regolitic; form is sandy loam. According to World Reference Base (FAO, 2014) this is Vertic Leptosol (Eutric);

- Eutric brown soil (Eutric cambisol), subtype on ultrabasic patrent material, variety regolitic, form very skeletal. According to World Reference Base (FAO, 2014) this is Leptic Vertic cambisol (Eutric);

- Ilimerised soil, subtype on the silicate parent material, variety typicall, form clay-loam. According to World Reference Base (FAO, 2014) this is Vertic Luvisols (Eutric).

Ecologic-productional value of selected soil types is mainly conditioned by the character of the parent material. Also, the impact of climate and topography is very important. Ranker provides xero-thermophilous conditions for vegetation, due to small depth, high content of rock fragments and good water permeability. Eutric brown soil is usually highly productive type, but on the serpentinites this potential is slightly reduced also due to water deficit, high content of rock fragments and sandy texture. Ilimerised soil is developed mostly at the bottom of the slopes. It is very deep, texture differentiated and well-structured soil. The content of rock fragments is increasing with depth and has a positive effect on the water-air regime. Luvisol is more mesophilous comparing to the ranker and eutric cambisol, so under these conditions, it has the greatest ecologic-productional potential for forest communities developing on ultramafic rocks in the research area.