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

<jats:sec><jats:title>Summary</jats:title><jats:p> <jats:list> <jats:list-item><jats:p>Tree regeneration on coarse woody debris (<jats:styled-content style="fixed-case">CWD</jats:styled-content>) is considered to be one the most ecologically valuable aspects of <jats:styled-content style="fixed-case">CWD</jats:styled-content> in forest systems. However, most studies have focused solely on uncovering the differences in establishment and growth on <jats:styled-content style="fixed-case">CWD</jats:styled-content> (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 <jats:styled-content style="fixed-case">CWD</jats:styled-content>.</jats:p></jats:list-item> <jats:list-item><jats:p>We analysed the effects of <jats:styled-content style="fixed-case">CWD</jats:styled-content> 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.</jats:p></jats:list-item> <jats:list-item><jats:p><jats:styled-content style="fixed-case">CWD</jats:styled-content> properties affected regeneration at the germination stage. There were some demographic differences between species relative to <jats:styled-content style="fixed-case">CWD</jats:styled-content> 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 <jats:styled-content style="fixed-case">CWD</jats:styled-content>, while their height growth was enhanced on conifer‐derived <jats:styled-content style="fixed-case">CWD</jats:styled-content>, particularly on spruce <jats:styled-content style="fixed-case">CWD</jats:styled-content>. Stumps enhanced establishment of all species and survival of conifer seedlings.</jats:p></jats:list-item> <jats:list-item><jats:p><jats:italic>Synthesis</jats:italic>. Our study shows that <jats:styled-content style="fixed-case">CWD</jats:styled-content> 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 <jats:styled-content style="fixed-case">CWD</jats:styled-content>. This highlights the need to include <jats:styled-content style="fixed-case">CWD</jats:styled-content> heterogeneity as a factor that can affect the role of <jats:styled-content style="fixed-case">CWD</jats:styled-content> in regeneration in forest ecosystems.</jats:p></jats:list-item> </jats:list> </jats:p></jats:sec>