DIGITALNA ARHIVA ŠUMARSKOG LISTA
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| ŠUMARSKI LIST 5-6/1961 str. 55 <-- 55 --> PDF |
The Aleppo-Pine can be consideređ as the most suitable speeies for achieving this objective. The introduction of Aleppo-Pine in´to ithe macchias and garigues can be carried out in the best and cheapest manner by sowing seed on the previously stubbed-out and prepared circular plots sized 4—8 ,sq. m., which ought ito be also manured with an adequate fertilizer. On each hectare there are to be eatablished about 200 of such circular plots. ff the wood obtained by cutting less valuable elernenfe of macchias and garigues can be used for lime burning, then rt is recommended to perform their cuitting with a 50—lOC´/o intensi´ty by applying previouisly a broadcast sowing of the Aleppo-Pine seeds over the whole area. Besides that after this cutting one can also apply partialljy a stubbing-out, preparation and manuring (with artificial fertilizer) of about 200 circular plots sized 1—3 !sq. m. In this case the ejcpenditures of sovving are by half lower ithan in the case described previously, and the sowing is usually isuccessful. Afforestation of stony grounds with Aleppo-Pine is carried out toy sowing seeds in circular plots sized 0,5^—2 sq. m. i. e. 600—1000 plots per heotare. Such sfforestation is more expensive than introducing Aleppo-Pine into macchias. For this purpose of establishing highly resinous stands it is necessary to collect only the seeds from highly resinous trees. Scientific investigation ought to establish the obvious characteristics of such trees. With seeds of such trees — besides regular afforestation — one should also establish a separate seed supplying štand which in the near future should bear seeds of special quality. The method of management of Aleppo-Pine forests (thinnimgs, choice of _elite trees, manner and time of introducing trees into tapping, method of resin-tapping, rdtation etc.) ought to be prescribed by Khe wor´king plan to irasure evennes and permanency of highest resin yields. For the improvement of the existing forests as well as raising and tending of new P.ine stands sufficient funds should be secured in order to harmonize the advancement of the whole economy of the country. PRILOG POZNAVANJU DUŠIKA U DRVETU Dr ing. Ivo Opačić Poznato je da drvo sadržaje vrlo malo dušika, odnosno malo kemijskih spojeva koji u molekuli imaju dušik. Prisutnost dušika veoma je važna za normalni razvoj i život, jer u nedostatku dušika biljka vidljivo počinje da nazaduje, žuti, kržljavi, a lišće počinje opadati. Dušik dolazi u biljci u spojevima koji se nalaze u proteinima, vitaminima, lipoidima, encimima i alkaloidima, a kod zelenih dijelova biljke u klorofilu. Prema Beckeru i Dillingeru, najmanje dušika ima u korijenu, sve više prema vrhu, a najviše u lišću. Podaci o istraživanju dušika u drvetu veoma su oskudni i nesistematski obrađeni. Prema Hagglund u sadržaj dušika u drvetu varira u granicama od 0,1—0,5%. Po. Schwalbeu i Beckeru, sav dušik je proteinskog porijekla, a ima ga 0,10—0,17%. Po Hartig u sadržaj dušika u drvetu bukve varira sa godišnjom dobi i stvaranjem ploda. U vrijeme jake oplodnje sadržaj dušika u drvetu je manji. Od posebnog interesa za ova istraživanja, bio je raspored i količina dušika sadržanog u drvnoj masi ispitivanih vrsta drva. Glavni nosilac dušikovih spojeva u drvnoj masi je kambij. Allsopp i Misra našli su da kambij jasena (Fraxinus elatior L.) sadrži 29.4´% proteina, a brijesta (Ulmus sativa Mili.) 30%, dok u isto vrijeme u drvnoj masi ima jasen 1,37%, a brijest 1,73% proteina. |