broj: 3-4/2000
pdf (37,7 MB) |
|
||||||||||||||
| IZVORNI ZNANSTVENI ČLANCI | ||
| Šalek-Grginčić, J. | UDK 630* 622 + 624 (Quercus petraea Liebl.) | |
| Regulation of Private Forests of Sessile Oak (Quercus petraea Liebl.) in the Area of the Karlovac Forest District pdf HR EN | 123 | |
| Summary: Privately owned forests are an integral part of forest ecosystems. Private forests are characterised by their small surface areas, so that estates of about ten hectares per owner are very rare. Such small-sized estates are often made even smaller by being cut into several small parts.With the area of 40,713 ha, private forests in the area of Forest Office Karlovac make up 33% of the total area of forests and forestland. The research into the basic structural elements for the purpose of establishing the real state and methods of management in private forests has encompassed natural preserved stands of sessile oak of high silvicultural form in the Forest Administration Karlovac, Forest Office Duga Resa. A total of five plots sized 0.50 - 1,00 hectare were established in the climatozonal belt of the association of sessile oak and common hornbeam (Querco petrae - Carpinetum illyricum Horv. 1938). The stands in five age classes (II - VI) in the site of the first class quality were included. On the basis of the obtained results and their interpretation, several conclusions may be drawn related to the management of sessile oak stands in private forests. 1. All studied stands have bell-like (uni-modal) distribution of breast diameters characteristic of even-aged stands. Due to natural processes and methods of management, bigger or smaller aberrations of individual distributions have occurred in relation to the theoretical model of Gauss´s normal distribution. 2. Since oak is a heliophyllic tree species in which the method of management is governed by the age of the stand and not its diameter class, sessile stands of high silvicultural form should be managed exclusively according to the principles used for even-aged stands. 3. In privately owned stands, in which regular and expert management is most commonly absent, mean trees often have smaller diameters, and at times smaller heights than is prescribed in table values for a certain site class. For more reliable site assessment it is necessary (for certain stand ages) to compare not only the heights of mean trees (both table and concrete), but also check whether the heights in height curves of concrete stands are within the boundaries of the quality (Table 10). Assessment will not be reliable if concrete stand height curves are compared with Šurić´s site quality height curves (Figure 10). Mean stand heights can be compared, however, as seen in the mentioned graph. 4. Despite the fact that the stands in question have not been regularly managed, relatively high values of basic structural elements were obtained in relation to the compared yield tables. The following total values of the basal area for individual stands per hectare were obtained (Table 9): 27.1 m2 in Plot 1 (II age class), 25.0 m2 in Plot 2 (III age class), 31.6 m2 in Plot 3 (IV age class), 30.5 m2 in Plot 4 (V age class), and 40.3 m2 in Plot 5 (VI age class). The growing stocks of the stands per hectare (for timber mass of trees up to 3 cm in diameter) are as follows: 204 m3 in Plot 1 (II age class), 272 m3 in Plot 2 (III age class), 418 m3 in Plot 3 (IV age class), 426 m3 in Plot 4 (V age class) and 617 m3 in Plot 5 (VI age class). The current annual volume increment of stands per hectare is also high: in Plot 1 (II age class) it is 12.3 m3, in Plot 2 (III age class) it is 9.5 m3, in Plot 3 (IV age class) it is 7.9 m3, in Plot 4 (V age class) it is 9.2 m3, and in Plot 5 (VI age class) it is 12.0 m3. However, if structural elements of sessile oak are compared with yield tables, it can be seen that almost all structural elements of sessile oak are lower than those in yield tables (Tables 11, 12, 13, 14, and 15). When the distributions of breast diameters of some species (hornbeam) are taken into consideration, then the differences between managed stands and those mentioned are evident. 5. The yield tables by Špiranec are adequate for determining the normality of sessile stands because timely and appropriate silvicultural procedures enable the achievement of the sizes of structural elements that correspond to these tables. 6. The obtained data also correspond well to Cestar´s standards. 7. Since the tables of the cited foreign authors do not reflect the local ecological conditions and since they were drawn up for both pedunculate and sessile oak, their use is not recommended. 8. It is well known that apart from genetic factors, external factors of selection also have a significant influence on the stand development. Therefore, expertly handled intervention also has vital effects on the development trend. In these stands, intervention is needed since their early youth, starting from tending and cleaning to regular thinning treatments, which are indispensable for obtaining a better quality increment, the formation of a stable stand structure and for preparing them for natural regeneration. Despite the small sizes of estates, the overall area of these forests is abundantly large. These forests should be studied in more detail because they have an invaluable role due both to their nonindustrial and economic functions. The imperative of the sustainable management and the preservation of biological diversity of the forest ecosystem demands that these forests be ensured all the prerequisites that will enable the application of management principles aimed at improving their condition and ensuring the sustainability of all their functions. Key words: basal area; evenaged stands; forest of high silvicultural form; growing stock; increment; private forests; sessile oak; site quality | ||
| Pintarić, K. | UDK 630* 232.1 (Larix europaea) 001. | |
| 30 Years of Research Into Larch of Various Provenances in Bosnia pdf HR EN | 143 | |
| PREGLEDNI ČLANCI | ||
| Molak, B. | UDK 621.31 | |
| Unnecessary Environmental Pollution and Impoverishment of the Population in the Production of Electrical Energy pdf HR EN | 157 | |
| Sabadi, R. | UDK 630* 904 | |
| France: Forests of the Overseas Departments pdf HR EN | 171 | |
| STRUČNI ČLANCI | ||
| Božić, M. | UDK 630* 524 (Abies alba Mill.) | |
| What is the Real Amount of Fir Stocks in Croatian Forests? pdf HR EN | 185 | |
| Böhm, D. | UDK 630* 907.1 + UDK 551.48 | |
| Regressions in the Water Zone of the National Park Plitvička Jezera pdf HR EN | 197 | |
| Dimitrov, T. | UDK 630* 432 | |
| Future Wildfires Related to the Global Warming pdf HR EN | 203 | |