%0 Articles
%T Disturbance in boreal spruce forest – immediate dynamics from stand to understorey level
%A Hautala, Harri
%D 2008
%J Dissertationes Forestales
%V 2008
%N 74
%R doi:10.14214/df.74
%U http://dissertationesforestales.fi/article/1856
%X The immediate effects of two anthropogenic vegetation disturbances, (1) green-tree retention (GTR) patch felling and soil scarification by harrowing, and (2) understorey vegetation layer removal, were examined in boreal forest stands in Finland.

Effects of GTR patch felling and harrowing on tree uprootings (I), on coarse woody debris (II) and on epixylic plant community (III) were followed in upland and in paludified forest types. Uprootings increased considerably during 2-3 years after the felling and were more frequent in the paludified (47%) than in the upland forest (13%). After the harrowing, 68% of the CWD had disappeared from the felling area. Cover and especially species number of epixylics declined in the both areas during 1-2 years after the felling. The increasing size of GTR patch correlated positively with the number of epixylic species.

Regeneration of understorey vegetation community (IV), and Vaccinium myrtillus and Vaccinium vitis-idaea (IV) after different vegetation layer removals took four years in an old-growth forest. The regeneration occurred mainly by vegetative means and it was faster in terms of species richness than in cover. In the most severe treatment, recovery occurred merely by sexual reproduction. V. myrtillus recovered mainly by producing new shoots, while V. vitis-idaea recovered faster than the previous, mainly by increasing length growth.

For ecological reasons, use of larger GTR patches on paludified biotope could be recommendable. In felling areas, harrowing could be replaced with some other spot-wise method.

After moderate intensity level disturbance, recovery occurs rapidly by vegetative regrowth of the dominating species. High intensity disturbance may prevent the recovery of understorey community for years, while enabling also sexual regeneration of the initial species.

Local anthropogenic disturbances are currently increasing and they can interact during temporally short times, which should be taken in to account in the future forest management plans.