Data from: Biodiversity along temperate forest succession

1. The successional dynamics of forests – from canopy openings to
regeneration, maturation and decay – influences the amount and
heterogeneity of resources available for forest-dwelling organisms.
Conservation has largely focused only on selected stages of forest
succession (e.g. late-seral stages). However, to develop comprehensive
conservation strategies and to understand the impact of forest management
on biodiversity, a quantitative understanding of how different trophic
groups vary over the course of succession is needed. 2. We classified
mixed mountain forests in Central Europe into nine successional stages
using airborne LiDAR. We analysed α- and β-diversity of six trophic groups
encompassing approximately 3,000 species from three kingdoms. We
quantified the effect of successional stage on the number of species with
and without controlling for species abundances and tested whether the data
fit the more-individuals hypothesis or the habitat heterogeneity
hypothesis. Furthermore, we analysed the similarity of assemblages along
successional development. 3. The abundance of producers, first-order
consumers and saprotrophic species showed a U-shaped response to forest
succession. The number of species of producer and consumer groups
generally followed this U-shaped pattern. In contrast to our expectation,
the number of saprotrophic species did not change along succession. When
we controlled for the effect of abundance, the number of producer and
saproxylic beetle species increased linearly with forest succession,
whereas the U-shaped response of the number of consumer species persisted.
The analysis of assemblages indicated a large contribution of
succession-mediated β-diversity to regional γ-diversity. 4. Synthesis and
applications. Depending on the species group, our data supported both the
more-individuals hypothesis and the habitat heterogeneity hypothesis. Our
results highlight the strong influence of forest succession on
biodiversity and underline the importance of controlling for successional
dynamics when assessing biodiversity change in response to external
drivers such as climate change. The successional stages with highest
diversity (early and late successional stages) are currently strongly
underrepresented in the forests of Central Europe. We thus recommend that
conservation strategies aim at a more balanced representation of all
successional stages.