Epsilon Archive for Student Projects

Abstract

The increased demand for wood and at the same time declining biodiversity, especially
in species related to natural forests has brought to attention the need to find ways to
maintain natural forest components also in managed stands, not only in specially
protected areas. One possible method for increasing the number of species in a
production forest is using retention trees. A forest stand in Southern Sweden was
investigated to determine the effect of retained trees on the growth of Norway spruce
(Picea abies). A total of thirty-three plots were established in 5.5 ha stand with retained
oaks as plot centers, three oak release treatments (high release, medium release and no
release) were carried out on the plots. The results showed a reduction in individual tree
Norway spruce growth within the proximity of the retained oak. A larger diameter
increment was recorded around the gaps in comparison with no release plots, so some of
the loss in Norway spruce growth was compensated. At the whole stand level, there was
no significant effect of the retained trees on the growth of the spruce; however, this
could be caused by the imposed treatments and thinning in the stand, which might have
evened out the total retained tree effect. Further investigation is needed in determining
the compensation of growth around gaps and also a wider age range of Norway spruce
stands should be evaluated.