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LUCRĂRI ŞTIINŢIFICE Vol. 54 NR. 2 SERIA HORTICULTURĂ

LUCRĂRI ŞTIINŢIFICE Vol. 54 NR. 2 SERIA HORTICULTURĂ

LUCRĂRI ŞTIINŢIFICE Vol. 54 NR. 2 SERIA HORTICULTURĂ

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the satisfactory range. At the same time, the favorable impression shaped when<br />

analyzing the EEF for mixed and beech forests shall be also amended since these<br />

types of forest stand for 10% of the forest area only; pure Norway spruce forests<br />

represent the major share of the forest.<br />

Related to stand composition, before windthrows occur, in all three cases<br />

the EEF index mean values were situated in the optimum. After the windthrows,<br />

in the stands where the proportion of spruce was higher than 50% the EEF index<br />

values decrease with 2-2.5 points (figure 6). The effect of this decrease is the<br />

change of the ecoprotective effectiveness from optimal to satisfactory. At ten<br />

years after the windthrows the EEF index values remain in the same register.<br />

- EEF index values related to age classes<br />

In the studied area age classes III (41-60 years), IV (61-80 years) and V<br />

(81-100 years) represent 68% of the total surface, the stands included in these<br />

cases being most affected by windthrows.<br />

The stands from class I are below 15 meters height and are not vulnerable<br />

to wind but to snow. Stands included in VI and VII age classes have, usually,<br />

uneven aged structure, which is more resistant, and a high capacity of recovery.<br />

As for EEF index values, before windthrows all stands irrespective to age<br />

class show the optimal effectiveness (EEF>20); after windthrows these values are<br />

to be found only for II, VI and VII age classes (figure 7).<br />

We can conclude that for 68 % of the studied area ecoprotective<br />

effectiveness had decreased from optimal to satisfactory.<br />

Fig. 7 – Mean values of EEF index before and after<br />

windthrow related to age classes<br />

557<br />

Fig. 8 – Mean values of EEF index<br />

before and after windthrow related to<br />

stand structure<br />

- EEF index values related to stand structure<br />

In even aged stands the ecoprotective effectiveness is satisfactory both<br />

before and after windthrows with the remark that after windthrows the EEF mean<br />

value decreases with 2 points (from 19,5 at 17,5). In uneven aged stands the

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