Partitioning beta diversity at two spatial resolutions reveals biotic homogenisation with habitat degradation

This data pertains to lichen, fungi, and bryophyte species composition from 120 forest sites across Sweden.  The data is from a detailed species inventory by species experts in 2021 and 2021 in two regions in Sweden: Hälsingland and Värmland. For each taxa we have assemblage data from 20m radius plots in three different forest management types: Young forests (clearcut 20-30 years ago), Retention Patches (small patches of forest left unharvested during the young forest's harvesting phase 20-30 years ago), and Set-asides (larger patches of forest left unharvested partly for biodiversity conservation. These three forest management types reflect three different levels of habitat degradation: high degradation (young forest), medium degradation (retention patches), and low degradation (set-asides). Using this data, we used beta diversity partitioning to assess how community composition varied between habitat degradation level. We examined how pairwise total beta diversity, nestednes..., We undertook an extensive survey of 120 sites within Sweden, distributed evenly between the three different habitat degradation levels (low degradation: mature set-aside forests, medium degradation: retention patches, and high degradation: young forests, clearcut in ca 30 years ago, Rudolphi et al. 2014). At each site, we inventoried the presence of species from all three taxonomic groups in circular plots with a 20-m diameter. When retention patches were smaller than this, we surveyed the entire area of the retention plot, here defined as the area covered by the canopy layer of the dominant tree species.
Lichens were surveyed up to 2 m in height on all standing dead trees within the plot. A subset of living trees was also surveyed: three small (diameter at breast height of between 5 and 15 cm) trees and seven large (diameter at breast height of at least 15 cm) for each dominant tree species (either Norway spruce or Scotch pine). If insufficient trees from one size class were ..., , # Data from: Partitioning beta diversity at two spatial resolutions reveals biotic homogenisation with habitat degradation

[https://doi.org/10.5061/dryad.fttdz093x](https://doi.org/10.5061/dryad.fttdz093x)

## Description of the data and file structure

This data is assemblages data for bryophytes on deadwood, lichens on all substrates, and polypores and select cortioid fungi on deadwood surveyed in 2022-2023 in 120 20m circle plots in Sweden. The plots are distributed evenly between young forests (clearcut 20-30 years ago), retention patches in these young forests, and more mature forests set-aside for conservation.

This data is associated with [https://doi.org/10.1111/ddi.70080](https://doi.org/10.1111/ddi.70080)

### Files and variables

There are three CSV data filed in this dataset, each relating to one of the three taxa surveyed (bryophytes, lichens, and polypores).

Data come from three types of forest management type: Retention patches (groups of trees left unharvested during ...,