DOI: 10.5061/dryad.061tr
title: Data from: Bat communities respond positively to large-scale thinning of forest regrowth

description: Over half of the world's forests are secondary regrowth and support
 considerable biodiversity. Thinning of these forests is a widespread
 management practice that can affect forest species, including echolocating
 bats and their prey. We compared total activity of 11 bat taxa, foraging
 activity of six bat guilds and biomass of 11 insect orders across four
 forest thinning categories in managed remnant eucalypt forests in
 south-eastern Australia: unthinned regrowth, forest thinned recently (0–4
 years) and in the medium term (5–10 years) and reference (mature open
 forest). Thinning had been carried out at large (˜350 ha) spatial scales.
 Total bat activity was 60% less and foraging activity was 80% less in
 unthinned regrowth, compared to reference sites, but activity levels were
 similar among thinned and reference sites. Insect biomass was greatest in
 unthinned sites, and while bat activity was related to prey biomass, this
 relationship was weak in unthinned sites. Together, this suggests that
 forest structure was more important than prey availability or time since
 thinning in influencing bat activity patterns. Synthesizing our findings
 with the broader literature on bats and thinning, we found support for a
 clutter threshold of 1100 stems ha−1, above which bat activity was
 markedly lower, across two continents (the USA and Australia) and four
 broad vegetation types (eucalypt, conifer, deciduous and mixed forests).
 While elsewhere bats with adaptive traits for open habitats generally
 respond positively to thinning, in our study, species with traits
 consistent with clutter tolerance (high call frequency and low wing aspect
 ratio) had lowest activity levels (up to 22 times) in unthinned regrowth
 compared to all other forest types. Synthesis and applications. Widespread
 dense regrowth forest can restrict movement and foraging of bats, even
 those adapted to clutter. We recommend thinning dense regrowth or
 plantations to below 1100 stems ha−1 when targeting bat foraging habitat,
 but effects of thinning on roost habitat and other forest biota require
 further investigation.
description: Bat activity data with
 environmental variables and geographic locaitonsData includes all data
 used in bat models. Columns 1-2 give random effects (site and management
 unit), column 3 is thinning category. Columns 4:5 are the univariate bat
 response variables (total activity and foraging activity). Columns 6:28
 are multivariate response variables: taxa activity (cols 6:16), guild
 activity (cols 17:22) and guild foraging activity (cols 23:28). All bat
 activity are in calls per night (foraging activity measures represent
 foraging calls or 'feeding buzzes' per night). Columns 29:41 are
 environmental variables described in Table S1 of the supplementary
 material of the paper (see attached README file). Columns 42:43 are
 geographic coordinates (latitude and longitude, WGS84) for each
 site.thinning.bat.data.csvInsect biomass data with environmental variables and geographic locationsData includes all data used in insect models. Columns 1-2 give random effects (site and management unit), column 3 is thinning category. Column 4 is the univariate insect response variables (total insect biomass). Columns 5:15 are multivariate response variables including biomass for each order. All insect biomass measures are in grams. Columns 16:28 are environmental variables described in Table S1 of the supplementary material of the paper (see attached README file). Columns 29:30 are geographic coordinates (latitude and longitude, WGS84) for each site.thinning.insect.data.csv