DOI: 10.5061/dryad.mkkwh71bn
title: Forest clear-cuts support diverse moth fauna but lack common grassland species

description: Forests ecosystems sustaining most of the terrestrial biodiversity are
 under increasing anthropogenic pressure. Both the protection of the
 remaining natural forests and the mitigation of the negative effects of
 silviculture are of primary conservation concern. Clear-cut areas are the
 main open habitats in production forests, potentially offering temporary
 refuge for species from declining semi-natural grasslands. Although
 several groups of flower-visiting insects, including butterflies, have
 been reported to thrive in clear-cuts, a taxonomically comprehensive
 understanding of the insect fauna utilising these habitats is lacking. In
 this study, we examined the assemblages of nocturnal macromoths
 (Lepidoptera: Marcoheterocera) in forest clear-cuts of varying age (2–6
 years) and regeneration regimes (natural vs. artificial) in Northern
 Europe. Using automatic sugar-bait traps, we sampled 50 clear-cuts and
 three pairs of forest-grassland reference sites over two summers.
 Nocturnal moths of the clear-cuts were highly diverse, harbouring 50% of
 the regional species pool of noctuids. However, several common
 grassland-associated species, as well as a few forest species, were nearly
 absent. Although the similarity between clear-cut and forest assemblages
 increased with clear-cut age, the recorded characteristics of the
 clear-cuts had little overall influence on moth assemblages. Artificially
 regenerated clear-cuts, characterised by a more open vegetation structure,
 supported slightly higher moth species richness and diversity compared to
 naturally regenerating sites. Policy implications: Our results highlight
 the role of forest clear-cuts in supporting insect biodiversity. As such,
 clear-cuts warrant special consideration as a distinct habitat type.
 However, the effects of clear-cut regeneration and maintenance methods on
 assemblages of moths appear weaker than in various other insect groups.
 More importantly, the absence of several common grassland species
 highlights that clear-cuts cannot fully replace traditional open habitats.
 This underscores the importance of conserving semi-natural grasslands.
description: # Forest clear-cuts support diverse moth fauna but lack common grassland
 species Dataset DOI: [10.5061/dryad.mkkwh71bn](10.5061/dryad.mkkwh71bn) ##
 Description of the data and file structure The data contains species list
 and abundances of moths sampled in forest clear-cuts, the clear-cut
 parameters, as well as data from a reference study conducted in forests
 and meadows, with the purpose of studying forest clear-cut moth
 assemblages and comparing these to forest and grassland moth fauna. Moths
 were sampled with automated sugar-bait traps.  ### Files and variables
 #### File: clearcut\_2022.xlsx **Description:** Species list and
 abundances of moths in samples collected from forest clear-cuts  #####
 Variables * ID (clearcut ID) * Species name * Abundance of the species in
 sample * Collection date of sample; the trap was set up 5 days previously
 #### File: reference\_2023.xlsx **Description:** Species list and
 abundances of moths in samples collected from forest and grassland
 reference sites ##### Variables * ID (village name) * Landscape (type of
 reference site: forest, landscape) * Species name * Abundance of the
 species in sample * Collection date of sample; the trap was set up 7 days
 previously #### File: clearcut\_properties.xlsx
 **Description:** properties of the clear-cuts ##### Variables * ID
 (clear-cut ID) * Type (artificially or naturally regenerated clear-cut) *
 Year (year of harvesting) * Tree sp. (dominant tree species before
 harvesting) * Field (1=clear-cut is adjacent to a field; 0=clear-cut is
 not adjacent to a field) * Grassland (1=clear-cut is adjacent to a
 grassland; 0= clear-cut is not adjacent to a grassland) * Area (of the
 clear-cut, in ha)