||Among stand heterogeneity is key for biodiversity in managed beech forests but does not question the value of unmanaged forests: Response to Bruun and Heilmann-Clausen (2021)
||Schall, P.; Heinrichs, S.; Ammer, C.; Ayasse, M.; Boch, S.; Buscot, F.; Fischer, M.; Goldmann, K.
; Overmann, J.; Schulze, E.-D.; Sikorski, J.; Weisser, W.W.; Wubet, T.
; Gossner, M.M.
|Journal / Serie
||Journal of Applied Ecology
||BZF; BOOEK; iDiv
||T5 Future Landscapes
||deadwood; even-aged forests; gamma diversity; landscape composition; old-growth structures; strict forest reserves; tree related microhabitats; uneven-aged forests
- Schall et al. (2020) assessed how a combination of
different forest management systems in managed forest landscapes
dominated by European beech may affect the biodiversity (alpha, beta and
gamma) of 14 taxonomic groups. Current forest policy and nature
conservation often demand for combining uneven-aged managed and
unmanaged, set-aside for nature conservation, beech forests in order to
promote biodiversity. In contrast to this, Schall et al. (2020) found
even-aged shelterwood forests, represented by different developmental
phases, to support highest regional (gamma) diversity.
- By pointing out that unmanaged forests included in
our study are not old-growth forests, Bruun and Heilmann-Clausen (2021)
challenge our conclusion as not providing sound scientific advice to
societies. It is true that the studied unmanaged forests are not
representing old-growth forests as defined in the literature. However,
we demonstrate the representativeness of our unmanaged forests for
current beech forest landscapes of Central Europe, where managed forests
were more or less recently set-aside in order to develop old-growth
structures. We also show that the managed and recently unmanaged forests
in our study already differ distinctively in their forest structures.
- We use this response to stress the role of forest
reserves for promoting certain species groups, and to emphasise their
importance as valuable research sites today and in the future.
- Synthesis and applications. We see two main
conclusions from our study. First, unmanaged forests still matter. We
agree with Bruun and Heilmann-Clausen (2021) on the general importance
of unmanaged, old-growth or long-untouched forests, and we do not
question the importance of set-aside forests for biodiversity
conservation. However, a complete complementarity to managed systems may
only reveal after many decades of natural development. Second,
safeguarding biodiversity in largely managed forest landscapes should
focus on providing a landscape matrix of different developmental phases
with varying environmental conditions rather than on maximising the
vertical structure within stands. Such landscapes can partly compensate
for structures that are still missing in vital, dense and closed forests
recently set-aside or for unsuitable phases that may occur due to a
cyclic synchronisation of forest structures in unmanaged forests.
|Schall, P., Heinrichs, S., Ammer, C., Ayasse, M., Boch, S., Buscot, F., Fischer, M., Goldmann, K., Overmann, J., Schulze, E.-D., Sikorski, J., Weisser, W.W., Wubet, T., Gossner, M.M. (2021):
Among stand heterogeneity is key for biodiversity in managed beech forests but does not question the value of unmanaged forests: Response to Bruun and Heilmann-Clausen (2021)
J. Appl. Ecol. 58 (9), 1817 - 1826