LUCRĂRI ŞTIINŢIFICE Vol. 54 NR. 2 SERIA HORTICULTURĂ

a number of about 40 ample windthrows have rushed upon the forests of
Bucovina, among which the biggest were in 1947-1948, 1964, 1969, 1975, 1982,
1995 and 2002 (Popescu Zeletin, 1951, Dissescu, 1962, Marcu et al., 1969, Ichim, 1976,
1988, Barbu, Cenuşă, 1987, Popa, 2002). On 6 th -8 th March 2002, because of some
storms which affected especially the upper basin of Moldavia River, Moldovița
basin and mainly Upper Suceava basin, there were wind throws and breaks of
4.000.000 cubic meters.
Studying the condition under windthrows occured help us to known the
relations between forests and environment (Popa, 2002). Less known, due to the
quantification difficulties are the effects of this phenomenon on the remaining
stands and their functions.
The aim of this paper is to study the influence of windthrow on
ecoprotective functions of the forests. Starting from the necessity to quantify the
structure-function relation, a global index was searched – EEF index.
MATERIAL AND METHOD
The study area is situated in Northern Romania, in the Tomnatec Forest district
- Production Unit VI Tomnatec (47 0 25’ N, 25 0 30’ E) (figure 1) which experienced
storms in March 2002. The investigations were carried out in protected, even and
uneven aged spuce and mixed forests. Most of the stands are located between 800
and 1000 m a.s.l. Norway spruce is the dominant tree species (77%). The forest was
preveously under protection and no intensive management had been carried out in the
area for decades. The stands ages ranged from 1 to 120 years.
Fig. 1 - Research area
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Starting from the need to
quantify the structure-function
relation, a global index was
necessary - EEF index –
ecoprotective effectiveness
index. This index was proposed
by ICAS (Cenușă, 2000) based
on Gundermann index
(Gundermann, 1974).
To compute EEF index different stand characteristics were used: crown density,
stand structure, composition, rooting, snow/wind/insects damages, age, successional
dymanics and anthropic damages. Each of them had received a general share and a
special share as it is presented in table 1.
EEF index formula is:
where:
P i represent the general share,
p i is the special share.
The EEF index was computed for each compartment of production unit VI
Tomnatec before windthrows, immediately after windthows and ten years after
windthrows. The rating scales for EEF index are presented below: