TITLE:
What Happens after the Gap?— Size Distributions of Patches with Homogeneously Sized Trees in Natural and Managed Beech Forests in Europe
AUTHORS:
L. Drössler, E. Feldmann, J. Glatthorn, P. Annighöfer, S. Kucbel, V. Tabaku
KEYWORDS:
Forest Structure, Natural Forest Dynamics, Tree Neighbourhood Relationships, Close-to-Nature Management, Fagus sylvatica, Central Europe
JOURNAL NAME:
Open Journal of Forestry,
Vol.6 No.3,
June
2,
2016
ABSTRACT: A novel but simple approach for describing stand structure in natural and
managed forests driven by small-scaled disturbances is introduced. A primeval
beech forest reserve in Slovakia and two beech stands in Germany with different
management histories were studied, and their forest stand texture was analysed
in terms of tree coordinates, stem diameter, and crown radius. Neigh-bouring
trees of similar size with estimated contact of their crowns were assigned to
tree groups. The study goal was to estimate the number and size of such
homogeneous patches. In all cases, the number of tree groups in a particular
diameter class decreased exponentially as group size increased. Single trees
were predominant. Compared to simulated random tree distributions, the natural
stand exhibited a more clumped distribution of small trees and more regular
distribution of larger ones. The natural forest generally had smaller groups
than the managed even aged stand, but the smallest group sizes were found in
the uneven-aged selection forest. The simple analytical approach provided new
spatial insights into neighbourhood relations of trees. The continuous scale
from single trees to larger tree groups is an important achievement compared to
other analytical methods applied in this field. The findings may even indicate
a certain degree of self-organization in natural forests. Due to the
limitations associated with each method or statistical models, a joint
consideration of 1) gap dynamics, 2) forest developmental stages, and 3) size classes
of homogeneous tree groups is recommended. Relevant to forest practitioners,
the size class distributions enhance an understanding of the complex stand
structures in natural forests and therewith support an emulation of natural
forest dynamics in managed beech forests.