The mountain forests in the Ukrainian Carpathians are of a multifunctional importance. Therefore, to study them, a differentiated approach should be applied The specifics of forest management measures depend on the forest categories. The latter, in turn, should correspond to the types of management, namely the environmental, recreational, protective and economic ones. Each type requires an optimal structural organization of forest ecosystems. Due to the fact that various cutting systems were used in the forest science, two directions have emerged, namely the study of the “normal forest” and the study of the “absolutely uneven-aged forest”. The idea of a “normal forest” accounts for the necessity to divide tree stands into classes and age groups, and is used when clear cuttings are prevailing.
The aim of the study was to define a modern structure of the mountain forests in the Ukrainian Carpathians based on the dominant species and age groups within the functional categories.
Materials and Methods
For the study, we used the subcompartment database of the mountain forests in the Ukrainian Carpathians. The forests were divided by function, dominant species and age groups. Forest functional categories were as follows: 1 - nature conservation, 2 - recreational and health, 3 - protective, 4 - operational. The actual data were compared with the optimal distribution of forests by age groups, established based on accepted maturity ages for Ukrainian forests.
The mountain forests in the Ukrainian Carpathians occupy an area of 1 million 457 thousand hectares, where 1021 thousand ha are forests of the State Forest Resources Agency. The area of forested land is 967.1 thousand ha. Forest stands with the dominance of European beech occupy 43% of the area, Norway spruce – 42%, common silver fir – 8% and other species occupy 7%. The exploitable forests cover 45.5% of the area, the protective forests – 27.7%, the nature oriented forests – 17.5% and the recreational forests – 9.3%.
The forests where principal felling can be conducted make the core of the wood sources. Their area is about 487 thousand ha, of which 78% are the exploitable forests, 5% are the protective ones, 6% are recreational, and 11% are the nature oriented forests. Forests excluded from those of principal felling occupy 479.8 thousand ha.
Clear cuttings account for the fragmentation of forest cover, the prevalence of even-aged tree stands and their current distribution by age groups. In light of this, a continuous use of forests implies an optimal division of tree stands by age groups, that is, the principle of “normal forest” is used.
Forests that are possible for principal felling are characterized by uneven-aged structure. The proportion of some age groups within all dominant species differs from the optimality criterion by several times.
Maturing, mature and overmature tree stands prevail in secondary spruce forests within all forest categories. It is inappropriate to consider their age structure from the point of view of optimality, since they have to be replaced with virgin forest stands. The presence of their young stands points at certain gaps in reforestation.
In the non-exploitable forests, economic activity is also carried out. They are characterized by about 40% of clear felled log that is formed in mountain forests. It results in a decrease of the area of uneven-aged forests. Inadequate attention is paid for their conservation and recording, and the optimality criterion of the age structure are similar to those used for the exploitable forests. Considering their functional purpose, the idea of an “absolutely uneven-aged forest” is more appropriate here, and the main status indicator should be the long-term sustainability and stability of forest ecosystems.
The principle of the “normal forest” should be applied for forests liable to principal felling. These forests are currently characterized by an uneven age structure. At that, the proportion of some age groups within all the dominant species differs from the optimality criterion by several times. Furthermore, in non-exploitable forests, it is efficient to apply a close-to-nature forest management. The main forest status indicator should be long-term sustainability and stability. The presence of young stands points at certain gaps in reforestation.
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