DIGITALNA ARHIVA ŠUMARSKOG LISTA
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| ŠUMARSKI LIST 5-6/2007 str. 63 <-- 63 --> PDF |
J. Margaletić, M. Grubešić, T. Kalvi, G. Videc: UTJECAJ EUROPSKOGA DABRA (Castor fiber L.) ... Šumarski list br. 5-6, CXXXI (2007), 257-265 trees and bushes, representation of certain plant species on the terrain and measuring the damage height and diameter under the damage place. The research was carried out on six parallel transects from 16.50 to 37.80 m long and two meters wide on the mutual distance of 50 meters, vertical on the river Odra, by which thepossibility of their mutual intersection wasprevented. The length of transects was measuredfrom the bank to thefarthest plant which belonged to the transect and where the signs of a beaver’s activity were noticed (bites). All woody species were listed along the whole transect and their damages from beavers were categorised into thefollowing five categories: undamaged plants, freshly damaged, but unfelled plants, freshly felled plants, old damaged, but unfelledplants and oldfelled plants. The intensity of beavers activity was analysed on a transect 250 meters long, placed 15 meters pl from the bank, parallel with the river Odra water course. A AA habitat was put every five meters (the total of 49) of the square meter 10 m2 where the activity of beavers was estimated in the following five categories: 1. no activity, 2. very little activity, 3. medium activity, 4. much activity and 5 very much activity. The percentage of the damaged trees and bushes was determined on the smple of 523 plants, while the measurement of the damage height and diameter under the place of damage was done on the smple of 200 plants. The following plant species were determined: Corylus avellana L., Cornus snguinea L., Fraxinus angustifolia Vahl., Ulmus minor L., Carpinus betulus L., Salix alba L., Rhamnus catharticus L., Crataegus sp., Euonymus europaeus L., Pyrus pyraster Burgsd., Acer campestre L., Rubus fruticosus L. and Quercus robur L.) and Crataegus sp. (12 %). In the smple of examined plants 85.09 % were undamaged, 4.02 % old damaged, 7.65 % old felled, 0.19 % freshly damaged and 3.06 % of freshly felled. Most frequently damaged species were A. campestre (37 %) and Crataegus sp. (12 %). By examining the smple of 200 damaged plants it was established that the average height of damages was 32.57 cm and the average diameter of plants under the place of damage was 3.45 cm. It was determined that beavers move mostly in the zone 15 m from the bank and that there maximum activities were 42 m from the water course. course. Key words: European beaver (Castor fiber L.), lowland forests,activity, damage, plants, food |