DIGITALNA ARHIVA ŠUMARSKOG LISTA
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ŠUMARSKI LIST 3-4/1956 str. 12 <-- 12 --> PDF |
Summary The author discusses the size of growing stock (minimum volume) per 1 ha. left immediately after the cut in the selection forest. For this purpose on 6 sample plots the total volume of all stems i> 10 cm. d. b. h. was measured, and the stems classified after their species. By measurement of the stem heights the site quality for every tree species growing on sample plots in question was established. Then, in collaboration with several forest officers the author carried out the markings of trees to be felled as -carefully as possible. All data collected on plots were brought to the measurement unit i. e. to the area of 1 ha. Then he tabulated the surveys of the grawing stock and the volume cut, as well as the growing stock left after the felling, i. e. the actual volume and the volume which — by Šurić´s and Matić´s standards-should remain after fellings according to the actual stand conditions. By comparing these data with Šurić´s standards, the .author came to the conclusion that the upper limits of Šurić´s standards closely approach the actual volume left after the cut, which is to be increased only for about 6% in order to reach the volume of growing stock remained after the actual markings per 1 ha. This in particular refers to Fir and Spruce, while for Beech on site class IV it was established that the actual volume of its growing stock after cut fully harmonizes with Surić´s data (along with the upper limits of his standards). Finally the author mentions that the said 6 sample plots are insufficient to permit drawing of definite conclusions in this question. Nevertheless, the findings on these plots give symptomatic and useful data. He points out the need for further investigation of this problem on a larger number of experimental management areas which would supply a more reliable and positive basis. SUZBIJANJE POTKORNJAKA ZATROVANIM LOVNIM STABLIMA Ing. Ivan Spaić Uvod P P otkornjake suzbijamo pomoću t. zv. lovnih stabala. Lovna stabla su zamke, u koje nastojimo primamiti potkornjake kako bi ih odvratili od zdravih stabala te tako skoncentrirane mogli lakše uništiti. Metoda je stara gotovo stoljeće i pol, no i danas se najčešće primjenjuje u svom prvotnom obliku. Posao oko suzbijanja potkornjaka pomoću lov. stabala općenito je težak jer traje tokom skoro cijele godine, uvjetuje stalnu i pomnu stručnu kontrolu rada, angažira znatnu radnu snagu, skup je, a uza sve to nesiguran obzirom na krajnji rezultat. U praksi se naime primjenom ove metode često puta ne postižu očekivani rezultati. Nerijetko se zbog nestručnog postupka postiže čak obratan učinak t. j . umjesto suzbijanja pogoduje se širenju potkornjaka. Za uspjeh akcije od posebne je važnosti pravilno odrediti vrijeme otkoravanja lov. stabala. Neuspjesi su najčešće uzrokovani upravo time što se lov. stabla kasno otkoravaju. Prigodom otkoravanja te odnošenja kore na mjesto spaljivanja najveći dio ličinki i kukuljica padne na tlo i tu se nesmetano dalje razvija. Na vatri se ustvari spali uglavnom prazna kora. Time je dakako promašena svrha čitave akcije. |