DOI: 10.5061/dryad.k3j9kd5m4
title: Surrounding landscape composition influences saproxylic beetle assemblages after prescribed burning

description: Biodiversity is affected by local and landscape factors, yet which of
 these is most important seems to vary depending on species group and
 context. Understanding how environmental factors affect species at
 different spatial scales is crucial for effective conservation planning.
 Here, we examine the influence of local and landscape characteristics on
 saproxylic and fire-favored beetle populations after prescribed
 burning.  Beetles (Coleoptera) were collected using flight
 intercept traps at 23 sites across three regions in Sweden. Prescribed
 burning had been conducted on the sites 4–7 years earlier. We analyzed the
 relationships between species richness, abundance community composition,
 and environmental variables at both local (burn sites) and landscape
 scales (2, 5, 10, and 20 km radius around the burn sites). Local variables
 were deadwood volume, canopy cover, and burn extent. Landscape variables
 included area of forests that were: protected, old (&gt;120 years),
 clear-cut and burned, and the standing timber volume of Scots pine, Norway
 spruce, and deciduous trees.  In total we recorded 3094
 saproxylic beetles, belonging to 188 species. Of these 1153 individuals
 (37 species) were classified as fire-favored. No local variables had a
 significant influence on beetle richness or abundance. For landscape
 relationships, 5 and 10 km scales were most relevant for analyzing
 saproxylic beetle responses. At these scales saproxylic beetle richness
 was positively associated with the protected forest area, whereas
 abundance showed a negative relationship. In contrast, richness of
 saproxylic beetles was negatively associated with the area of clear-cuts,
 while abundances of saproxylic and fire-favored species were positively
 associated. Species richness was similar across regions, whereas species
 composition varied. The proportion of old forests was an important
 variable contributing to regional dissimilarity in species
 composition.  Synthesis and applications. Our study highlights
 the importance of the surrounding landscape for shaping saproxylic beetle
 communities after prescribed burning. Forest management and conservation
 measures within a 5-10 km radius of prescribed burns can influence beetle
 assemblages post-burn and should be considered when planning burns aimed
 at promoting saproxylic beetles. In addition, as species composition
 varied across regions, this indicates that prescribed burning in different
 regions complements each other.
description: # Surrounding landscape composition influences saproxylic beetle
 assemblages after prescribed burning Dataset DOI:
 [10.5061/dryad.k3j9kd5m4](10.5061/dryad.k3j9kd5m4) ## Description of the
 data and file structure This dataset contains data required to replicate
 analyses in Ramberg et. al (2025). It includes data from 23 sites were
 prescribed burning had been conducted (burned 2015-2018), all within
 boreal forests in protected areas. The sites were grouped in three
 regions, North, Central and South, (exact locations can be found using
 coordinates in the attached site_coordinates file). The data collection
 included sampling beetles as well as collecting landscape and site data.
 Beetles were sampled using flight intercept traps (4-5 per site) which
 were up for approx. 6 weeks during the summer of 2022 (May to July). A
 mixture of propylene glycol and water was used to preserve beetles. The
 beetle were then identified to species level. In the study only saproxylic
 beetles were analyzed. The dataset included here however contains all
 beetle species captured. For landscape data, (Landscape buffer files) data
 was collected from The Swedish Civil Contingencies Agency, County boards,
 Life Taiga, Sveaskog, Holmen, SCA, and Stora Enso, Swedish Environmental
 Protection Agency and Swedish Forest Agency.  Data included the area of
 burned forest (wildfires and prescribed between years 2012-2021),
 protected forest, clear-cut forest (between years 2012-2021), forest older
 than 120 years, and standing volume per hectare of spruce, pine and
 deciduous trees. Landscape data was calculated for circular landscapes at
 four spatial scales, 2, 5, 10, and 20 km radius from the burn site
 perimeter using ArcGIS (ESRI 2020). Local (site) deadwood volumes
 (diameter at breast height ≥10cm) were collected in 50 m transects
 arranged 50 m apart in a grid pattern covering sites. For fallen deadwood
 the line intersect method was used (Van Wagner 1968) and standing deadwood
 was measured within 2.5 meters on each side of the same transects used for
 estimating fallen deadwood. We then analysed how landscape and local
 variables influenced species richness and abundance of saproxylic beetles
 after prescribed burning.  ### Files and variables #### File:
 2km\_landscapebuffer.xlsx **Description:** Landscape variables at 2 km
 (radius) circular landscapes around burn sites. All variables are where
 the total area was calculated in hectares (ha) are also presented in % of
 total buffer area.  ##### Variables * Site- all the sites in the study *
 presfire- prescribed fire, for the years 2012-2021 * wildfire-
 wildfire, for the years 2012-2021 * fire- prescribed fire and wildfire,
 for the years 2012-2021 * protectforest- protected forests (national
 parks, nature reserves, Natura 2000, and woodland key habitats) *
 clearcut- clear-cuts, for the years 2012-2021 * oldforest- forests older
 than 120 years * pine_mean- mean standing volume per hectare of Scots
 pine (m3 sk/ha ) * spruce_mean- mean standing volume per hectare of
 Norwegian Spruce (m3 sk/ha ) * dec_mean- mean standing volume per hectare
 of deciduous trees (m3 sk/ha ) #### File: 5km\_landscapebuffer.xlsx
 **Description:** Landscape variables at  5 km (radius) circular landscapes
 around burn sites. All variables are where the total area was calculated
 in hectares (ha) are also presented in % of total buffer area.  #####
 Variables * Site- all the sites in the study * presfire- prescribed
 fire, for the years 2012-2021 * wildfire- wildfire, for the years
 2012-2021 * fire- prescribed fire and wildfire, for the years 2012-2021 *
 protectforest- protected forests (national parks, nature reserves, Natura
 2000, and woodland key habitats) * clearcut- clear-cuts, for the years
 2012-2021 * oldforest- forests older than 120 years * pine_mean- mean
 standing volume per hectare of Scots pine (m3 sk/ha ) * spruce_mean- mean
 standing volume per hectare of Norwegian Spruce (m3 sk/ha ) *
 dec_mean- mean standing volume per hectare of deciduous trees (m3 sk/ha )
 #### File: 20km\_landcapebuffer.xlsx **Description:** Landscape variables
 at 20 km (radius) circular landscapes around burn sites. All variables are
 where the total area was calculated in hectares (ha) are also presented in
 % of total buffer area.  ##### Variables * Site- all the sites in the
 study * presfire- prescribed fire, for the years 2012-2021 * wildfire-
 wildfire, for the years 2012-2021 * fire- prescribed fire and wildfire,
 for the years 2012-2021 * protectforest- protected forests (national
 parks, nature reserves, Natura 2000, and woodland key habitats) *
 clearcut- clear-cuts, for the years 2012-2021 * oldforest- forests older
 than 120 years * pine_mean- mean standing volume per hectare of Scots
 pine (m3 sk/ha ) * spruce_mean- mean standing volume per hectare of
 Norwegian Spruce (m3 sk/ha ) * dec_mean- mean standing volume per hectare
 of deciduous trees (m3 sk/ha ) #### File: site\_coordinate.xlsx
 **Description:** Dataset with with 23 prescribed burn sites included in
 the study. This dataset includes their names, county, the protected area
 the are located within, and coordinates for the site center.  #####
 Variables * Name- name of the site in full * Site code name- name of the
 site used in other files and in analysis * County- the Swedish county the
 site was located in * Protected area- the name of the protected area the
 site was located in (nature reserve, natura 2000, national park) *
 E_swereff- Swereff E coordinates for site center * N_swereff- Swereff N
 coordinates for site center #### File: Beetlespecies\_data.xlsx
 **Description:** Data file with beetle species abundances per site as well
 as species information. In beetledata species abundances in each trap and
 site can be found. In speciescode the full names and abbrevations used in
 beetledata can be found along with red list status and ecological group.
 In metadata the ecological groups are described.  ##### Variables
 Beetledata * Site- site name * direction_of_trap- location of trap in
 relation to center (c= center, n=north, s=south, e=east, w=west) *
 trap_no- trap number * region- region site is located in (n=north,
 b=bergslagen (central), s=south) * year- year of the burn * the following
 column headings are species abbreviations, full names can be found in
 speciescode ##### Variables speciescode * family- beetle family
 * species- species name * code- abbreviation of species used in analysis
 also in Beetledata * redlist- red list status in Sweden 2020 (Least
 Concern (LC), Near Threatened (NT) and vulnerable (VU)) * group-
 ecological group information on these categories can be found in
 **metadata** #### File: deadwood\_local.xlsx **Description:** Dataset with
 deadwood site data, including information on deadwood tree species,
 diameter at breast height, height and if they are standing or fallen or
 dead before or after burning. na in dataset are cases when data was
 unreadable when transferring from paper to excel often due to rain
 damage.  ##### Variables * site- the 23 sites used in this study  *
 Transect_no- the code used to number each 50 m transect. * Directionality-
 the direction of the transect EW (east-west direction) or NS (north-south
 direction).  * Standing_Fallen- f for fallen deadwood and s for standing
 deadwood * Before_after- a for after (deadwood judged to have died after
 burning) and b for before (judged to be dead before burning) * Species-
 tree species when identifiable. Pine, spruce, birch, oak, alder, aspen,
 unknown.  * DBH_cm- the diameter at breast height in centimeters of trees
 measured * Height_m- Height in meters of standing trees measured *
 Noburn_m- the number of meters in a transect were no evident signs of
 burning could be found.  #### File: 10km\_landscapebuffer.xlsx
 **Description:** Landscape variables at 10 km (radius) circular landscapes
 around burn sites. All variables are where the total area was calculated
 in hectares (ha) are also presented in % of total buffer area.  #####
 Variables * Site- all the sites in the study * presfire- prescribed
 fire, for the years 2012-2021 * wildfire- wildfire, for the years
 2012-2021 * fire- prescribed fire and wildfire, for the years 2012-2021 *
 protectforest- protected forests (national parks, nature reserves, Natura
 2000, and woodland key habitats) * clearcut- clear-cuts, for the years
 2012-2021 * oldforest- forests older than 120 years * pine_mean- mean
 standing volume per hectare of Scots pine (m3 sk/ha ) * spruce_mean- mean
 standing volume per hectare of Norwegian Spruce (m3 sk/ha ) *
 dec_mean- mean standing volume per hectare of deciduous trees (m3 sk/ha )
 ## Code/software All statistical analyses were performed with R 4.3.3, (R
 Core Team 2024).