Data from: Regeneration processes on coarse woody debris in mixed forests: do tree germinants and seedlings have species-specific responses when grown on coarse woody debris?

Tree regeneration on coarse woody debris (CWD) is considered to be one the
most ecologically valuable aspects of CWD in forest systems. However, most
studies have focused solely on uncovering the differences in establishment
and growth on CWD (regarded as a homogeneous substrate) in comparison with
the forest floor. Our study concentrates on the underlying mechanisms of
germinant and seedling colonization patterns and demographic responses
relative to various properties of CWD. We analysed the effects of CWD
properties (decay class, form, species and diameter) on: (i) germinant and
seedling annual counts; (ii) annual germinant and seedling survival; and
(iii) seedling growth and height. Our study comprised three species
(beech, fir and spruce) over 7-year span in two old-growth stands in the
Western Carpathians, and employed generalized linear models and mixed
models to test for differences between species. CWD properties affected
regeneration at the germination stage. There were some demographic
differences between species relative to CWD properties. Decay class had
the most pronounced effect on beech, not only on its establishment but
also survival and growth. Beech and spruce established and survived in
higher densities on beech CWD, while their height growth was enhanced on
conifer-derived CWD, particularly on spruce CWD. Stumps enhanced
establishment of all species and survival of conifer seedlings. Synthesis.
Our study shows that CWD properties do influence seedling establishment,
growth, height distribution and survival. Moreover, there may be
trade-offs between seedling growth and survival among tree species growing
on different species of CWD. This highlights the need to include CWD
heterogeneity as a factor that can affect the role of CWD in regeneration
in forest ecosystems.