DIGITALNA ARHIVA ŠUMARSKOG LISTA
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| ŠUMARSKI LIST 6-9/1991 str. 78 <-- 78 --> PDF |
health of the Beech, floristic parameters, stand conditions and the most favourable way of management. The results of the investigation show that the range off the Fir and Beech communities in northern Croatia is disjunctjed and is located at Macelj Gora, Trakošćan, Strahinjćica, Ravna Gora, Ivančica, Medvednica and Papuk. The range of phytocoenoses covers 14,702 ha, while it is also found separately in other communities, in which it is not a characteristic species, covering another area of 2,835 ha. The range shows a tendency to reduce at Medvednica, but to in increase at Macelj and Papuk. The health state of the Fir has drastically deteriorated, and is becoming worse. In 1986 31% of the volume of wood belonged to one of 5 categories of crown damage due to the falling of needles, while in 1988 this figure was increased to 72%. By analyses of the floristic composition of vegetation at 128 phytocoenologica! surfaces, 20 x 20 m, and 9 surfaces, 60 x 60 m two associations were determined, of which one had two sub-associations, as follows: ass. Abieti-Fagetum pannonicum Rauš 1969 subass. typicum, nova subass. cardaminetosum trifoliae, nova ass. Blechno-Abieletum Horvat 1950 Typicum and cardaminetosum trifoliae arc new sub-associations, established and phytocoenologically recorded for the first time in this investigation. Geographical position and spatial arrangement of the ranges of forest phytocoenoses is shown on the map of northern Croatia on a scale 1:500,000 and on the five maps showing management units on a scale 1:25,000. Microclimaiic investigations determined essential differences in microclimatic characteristics according to particular mountain massifs and forest associations, in identical general climatic conditions the values of microclimatic elements, primarily the air temperatures on Macelj Gora, were considerably higher than on other mountains, which leads to the conclusion of the higher effectiveness of daily insolation. A characteristic microclimatic trait in the Blechno-Abieletum association is an increase in temperature values from the lowest to higher measuring gradients (up to 2 m), while this is not characteristic of the association Abieti-Fagetum pannonicum. in the Abieti-Fagetum association the temperatures in the crowns of Fir trees are regularly higher than at heights of up to 2 m, while in the Blechno- Abietetum they are different compared to other heights, depending on the aspects. Floristic parameters important for the management of Beech/Fir forests are characteristic species of associations and differential species of sub-associations, number and ground coverage by plant species, including Fir regeneration plants. A considerable increase in the number of the Fir regeneration plants was confirmed in 1989 compared to 1988. The number of plants varies according to particular mountain ranges and associations. The greatest increase in numbers was determined at Macelj Gora, where in 1988 there were 6,265 and in 1989 10,397 plants/ha of one-year-old Fir plants. In the Blechno-Abietetum association the number increased from 6,800 to 11,062 plants-ha in the same period. An increase in numbers was confirmed by analysis not only in one-year-old plants but also in two-year-old, three-year-old and older Fir plants. On the basis of floristic and ecological parameters it is suggested that the management of the Beech/Fir forests is governed by the principles of uneven-age, with the application of a selection — groupwise mixture in management. Spatial arrangement and number of groups, as well as management intervention in groups should be carried out in such a wey that it ensures lasting income and generally beneficial function of forest, including the highest possible level of health state, forests. Key words : synecology, phytocoenosis, microclimate, management of Beech Fir. |