Data from: Environmental conditions alter successional trajectories on an ephemeral resource: a field experiment with beetles in dead wood
Data files
Mar 16, 2020 version files 4.72 MB
Abstract
Successional processes can be observed for many organisms and resources, but most studies of succession have focused on plants. A general framework has been proposed, advocating that successional patterns in species turnover are predominantly driven by competition, dispersal or abiotic limitation, and that the patterning of species accumulation over time gives clues to which process is most influential in a given system. We applied this framework to succession in communities of wood-living beetles, utilizing ephemeral resources in the form of 60 experimentally created dead aspen high stumps. High stumps were created at sun-exposed sites (high ambient temperature; favorable abiotic conditions) and shaded sites (low ambient temperature; abiotically limiting conditions). The sites were intermixed, ensuring similar dispersal opportunities. Beetle species richness and abundance were monitored with flight interception traps over four consecutive years. Consistent with predictions from the tested framework, several beetle functional groups accumulated species more slowly at the unfavorable shaded sites than at the favorable exposed sites. Species richness at the exposed sites increased rapidly to a plateau, consistent with a limiting effect of competition on community development. Similar results were obtained for beetle abundance and community structure. Part of the variance in beetle community structure was jointly explained by habitat and fungal community composition, suggesting that differences in the composition and developmental rate of fungal communities in the two habitats contributed to the observed patterns. Targeted experimental studies are now required to decisively establish what processes underlie the contrasting successional trajectories in the two environments.
Methods
Data collection: The dataset consists of counts of saproxylic beetles sampled in managed forest in the southern boreal vegetation zone in Southern Norway. The forest was dominated by spruce (Picea abies), with Scots pine (Pinus sylvestris), birch (Betula pubescens) and aspen (Populus tremula) as subdominants. Beetle sampling was conducted by means of large (40cm x 60cm) trunk-mounted window traps. The traps were mounted on a total of 60 aspen trees. The traps faced south and were mounted with the lower edge of the window pane 1 m above ground. In the late fall of 2001, all trees were cut approximately 4 m above ground using detonating chord, in order to create standing high stumps. The resulting logs were left in place at the base of the high stump. The beetle trapping commenced in 2002-2005, operating from mid-May to mid-August in all years. The tress were distributed among two landscapes (Nordmarka and Østmarka), with 30 trees in each landscape. Within each landscape, 15 trees were located in sun-exposed clearings and 15 trees were located in shaded closed forest. Refer to the associated journal article for further details about study design and sampling.
Data processing: All trapped beetles were identified to species level. All non-saproxylic species and saproxylic species not associated with aspen were excluded from the dataset. The remaining species were categorized according to host tree affinity, namely aspen specialists (species mainly associated with aspen) and aspen generalists (species associated with aspen and other three species). The species were also grouped into trophic guilds, namely fungivores which feed on fungus or fungus-infested wood, wood-feeders which feed on dead wood, predators that attack other wood-living invertebrates, and omnivorous or saprophagous species that did not fit into the other categories. Refer to the associated journal article for further details about data processing.
Usage notes
The variables in the dataset are explained in the associated ReadMe file.