engleski

The ameliorative role of Aleppo pine (Pinus halepensis Mill.) in the regeneration of climatozonal vegetation

Background and Purpose: Aleppo pine (Pinus halepensis Mill.) is the most widespread sort, planted in the process of afforestation of degraded habitats, on the Mediterranean karst area. Its principal role as piomeer species on the island of Rab is to improve habitat conditions. The aim of the research is directed to determining ameliorative role during one rotation age. Materials and Methods: In the research of pine culture established in 1936, surveying of the forest stands structure four times (1971, 1975, 1985 and 1997). Plant sociological research is made according to the plant sociology methodology. The following pedophysiographic characteristics were determined: pH in water and 0, 01 M CaCl2 (1:2, 5), part of humus by oxidation in potassium bicromate, total nitrogen and indicators of humus ingredients in humus-accumulative soil horizon. Annual percentage of the number of dying trees was calculated by the formula: m = 1– (N1/N0 )1/t in which N0 is the number of trees at the beginning, and N1 – in the end of the monitoring period or time interval t. Emergence or ingrowth was calculated by the formula r = (ln(N0) – ln(N1))/T. Results: Structural elements showed that tree stock increased during the rotation age (294, 46 m3/ha), however the number of climatozonal broadleaves vegetation decreased (in 1975 - 3544 plants, in 1997 - 2395 plants). Their current number and coverage are insufficient for creating stable forest community of holm oak and manna ash. Forest stands conditions do not enable progressive succession of vegetation. Conclusions: Aleppo pine culture during one rotation age has not enabled the conversion of forest stands form. Edaphic conditions and ecological factors along with negative anthropogeneous influence do not contribute to improvement of habitat conditions.

degradation; habitat; pines; autochthonous vegetation

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