The biological and ecological characteristics of an special forest vegetation reserve kocje-korcula island

The natural phenomenon of Kocje, was declared as a special reserve of forest vegetation in 1962, while its main phenomenon is a forest of hundred-year-old holm oak trees (Quercus ilex L.). It is a reserve of seed production with some sedges. Apart from it ' s vegetation, Kocje has number of geomorphological forms. The forest of this reserve is classified as a forest of holm oak and black ash. The paper presents the results of extensive research conducted in the first half of 2015, which included structural, vegetation and microclimate measurements. The structural survey of the trees was carried out in the entire area of the reserve, and the vegetation and microclimatological research included 7 test plots. The results showed that the inventoried holm oak trees (140) show a constant decline in vitality, which is quite understandable and related to their age and most of numerous species are in the stage of ponics and saplings: Laurus nobilis and Viburnum tinus, while holm oak predominates in the upper layer. With regard to the structural tables of the stands on experimental plots 1.-7. (tables 2-8), as well as the total amount of wood stock, it is conformed that the closed part of the reserve's forest is still in the stage of high holm oak forest. Phytocenological recordings (table 12) are showing that there is an heterogeneity of cellular conditions, since, in addition to the typical species of the association Fraxino orni-Quercetum ilicis Horvatic (1956) 1958 (Black oak and black ash forest), depending on geological-morphological, hydrological, pedological and microclimatic conditions, additional species which are not typical for forest vegetation. Primarily ferns, rock vegetation, mosses, etc. The vegetation cover in Kocje reserve is anuniform. In the central part where old holm oak trees predominate, the tree layer coverage is 90-95 % (100 %), bushes cover 30-100 %. The coverage of the layer of ground growth is also different and depends on the coverage of the layer of bushes and trees, so it is from 5-80 %. In the reserve, we find a thick layer of undecomposed leaf (2-5 cm), and in "pockets", scraps between rocks, (10-15 cm). It is mostly applied by water during heavy rains. The microclimatic research has confirmed that the fluctuations of microclimatic elements (temperature and amount of light) depend on the degree of assembly of the stand in the layer of trees and bushes and the geomorphological conditions on the surfaces (stone corridors, arched and narrow passages, boulders, obstacles, etc.).