Structure and utilisation of wood volume of damaged and dead peduncled oak trees in Spačva

Propadanje stabala hrasta lužnjaka jedan je od najznačajnijih gospodarskih i ekoloških problema u šumarstvu Hrvatske. U radu su prikazani podaci o osutosti krošanja i propadanju stabala hrasta lužnjaka na uzorku stabala uz cestu Županja - Lipovac. Osutost stabala uz cestu iznosila je oko 60 %, dok je na cijelom području Spačve iznoslila oko 25 %. Utvrđeno je intezivno propadanje stabala hrasta lužnjaka 2003. godine, i smanjenje udjela tehničkog drva za oko 10 % kod stabala s velikom osutošću krošanja. Udio furnirskih trupaca kod stabala male i srednje osutosti bio je 50 % veći u odnosu na jako osuta i propala stabala.The dieback of peduncled oak forests in the management forests has been a major management and ecological issue of the Croatian forestry. The management problems relate to the decrease of the wood matter quality, the disturbances in the sustainable planning and management, and the cost increase resulting in lower revenues. The ecological problems relate to the causes of tree dieback, which are numerous and difficult to classify, and to the consequences for the habitats and the development of forest ecosystems. The paper presents the intensities of crown damage and the dieback of peduncled oak trees from four forestry units in the Spa~va area in 2002 and 2003. Varying visible trunk damage was analysed in relation to the crown damage degree. The analyses of tree dieback over the recent ten years were done. The utilisation of the wood volume of the dead and variously damaged peduncled oak trees was analysed. The paper discusses the issues of the total utilisation of the wood volume and the value of wood assortments of healthy trees in relation to the damaged and dead peduncled oak trees at the level of annual felling plan

Structure and utilisation of wood volume of damaged and dead peduncled oak trees in Spačva

Propadanje stabala hrasta lužnjaka jedan je od najznačajnijih gospodarskih i ekoloških problema u šumarstvu Hrvatske. U radu su prikazani podaci o osutosti krošanja i propadanju stabala hrasta lužnjaka na uzorku stabala uz cestu Županja - Lipovac. Osutost stabala uz cestu iznosila je oko 60 %, dok je na cijelom području Spačve iznoslila oko 25 %. Utvrđeno je intezivno propadanje stabala hrasta lužnjaka 2003. godine, i smanjenje udjela tehničkog drva za oko 10 % kod stabala s velikom osutošću krošanja. Udio furnirskih trupaca kod stabala male i srednje osutosti bio je 50 % veći u odnosu na jako osuta i propala stabala.The dieback of peduncled oak forests in the management forests has been a major management and ecological issue of the Croatian forestry. The management problems relate to the decrease of the wood matter quality, the disturbances in the sustainable planning and management, and the cost increase resulting in lower revenues. The ecological problems relate to the causes of tree dieback, which are numerous and difficult to classify, and to the consequences for the habitats and the development of forest ecosystems. The paper presents the intensities of crown damage and the dieback of peduncled oak trees from four forestry units in the Spa~va area in 2002 and 2003. Varying visible trunk damage was analysed in relation to the crown damage degree. The analyses of tree dieback over the recent ten years were done. The utilisation of the wood volume of the dead and variously damaged peduncled oak trees was analysed. The paper discusses the issues of the total utilisation of the wood volume and the value of wood assortments of healthy trees in relation to the damaged and dead peduncled oak trees at the level of annual felling plan

Can the structure of dormant cambium and the widths of phloem and xylem increments be used as indicators for tree vitality?

We investigated the structure and width of the dormant cambium and of the increments of phloem and xylem of Quercus robur to estimate their potential as indicators for tree vitality. The samples were taken from three woodlands, two in Slovenia [Krakovo forest (KRA) and Murska Suma (MUS)] and one in Croatia [Kobiljak (KOB)], with reported tree decline. The number of dormant cells seems to reflect the initial capacity of the cambium to accomplish cell division. With the exception of two trees at KRA, cell production was always higher on the xylem side than on the phloem side. The annual phloem increments were narrower, less variable among trees and with clear lower and upper limits. With increased cambial cell productivity, the share of the xylem in the total annual radial increment increased following a curvilinear function. In trees with an annual radial increment >3.5 mm, the xylem size represented more than 90 % of the total radial growth. The anatomical variables analyzed show that the most limiting environmental conditions seem to prevail at KRA, whereas the conditions at MUS seem to be most favorable in terms of radial growth. Analysis of the width and structure of xylem and phloem increments, the number of dormant cambial cells and their inter-relationships can provide additional information on the vitality of oaks