Surrounding landscape composition influences saproxylic beetle assemblages after prescribed burning
Data files
May 22, 2025 version files 298.32 KB
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10km_landscapebuffer.xlsx
16.19 KB
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20km_landcapebuffer.xlsx
16.52 KB
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2km_landscapebuffer.xlsx
15.47 KB
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5km_landscapebuffer.xlsx
15.80 KB
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Beetlespecies_data.xlsx
113.92 KB
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deadwood_local.xlsx
100.05 KB
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README.md
8.80 KB
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site_coordinate.xlsx
11.58 KB
Abstract
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 (>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.
Dataset DOI: 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).