Dataset DOI: 10.5061/dryad.d2547d8hj

Description of the data and file structure

These datasets and R codes contains all necessary information for reproducing the results of this study. They are grouped into three main folders:

plot_data_raw.zip

This is a folder containing group of datasets collected at the plot level. Each the dataset contains rows identified by "plot_ID". The plot_ID indicates the study plots from which all data were collected and is labelled as “1, 2, 3…187, 188”. All study plots used in this study were 1 hectare in size. For each file in this folder, only the key columns used in the analysis were described below.

species_data_raw.zip

Is a folder containing group of datasets used to calculate ecological diversity. It includes two types of data: species trait data and phylogenetic tree data.

r_script.zip

This is accompanying script to access data and reproduce the analyses reported in the manuscript.

Files and variables

File: plot_data_raw.zip

Description: 

1.     Community_data.csv: is a multivariate species include species x abundance data type and the data was structured as:

trap: indicating pitfall traps installed in three different location within each study plots. These three different locations were coded with c = central, nw = north west, and se = south east corners of the study plots.

The rest of the columns are the name of individual species identified in our samples.

2.     canopy_cover.csv:

Canopycover: Canopy cover data derived from canopy height models generated using UAV-based Structure-from-Motion (SfM) photogrammetry.

 3.     deadwood_volume.csv:

lying.dw: The volume of lying deadwood (m³/ha), estimated from a V-transect carried out during forest inventory on each plots.

 4.     prop_conifer.csv:

cf_share: the proportion of coniferous trees derived from inventory of all conifers with diameter at the breast height (DBH) > 7 cm.

 5.     ssci.csv:

ssci: the stand structural complexity index (SSCI) data, is a LiDAR-derived metric that quantifies three-dimensional arrangement of forest structural elements. The data was obtained from terrestrial laser scanners performed at the central, northwest and southeast corners of the study plots.

 6.     Understorey.csv:

Data of understory vegetation. Two variables were measured: hCover for the measurement of herbaceous cover. And SR_understory for the measurement of understory plant species richness. Both variables were estimated using visual assessment within 5x5 subplots along V-transect during forest inventory.

 7.     potential_prey.csv:

total.arth: is the potential prey availability (abundance) data, estimated by counting Diptera, Hemiptera, and Collembola caught in the same pitfalls as spiders.

Two columns containing count numbers of collembola and diptera_adult was also included in this dataset, although it was not used in our hypothesis testing. We used them for exploratory and supplementary purposes to informally investigate the role of individual potential prey for ground spider community.

8.     trap_days.csv:

trapdays: the difference in sampling duration among plots.

Missing values

Missing values are coded as NA.

File: r_script.zip

Description: 

• Data_preparation.R: r script for preparing the data before they are ready to be used for formal hypotheses testing,

• regression_corrected_R.E.R: script for testing hypotheses 1, 2, and 3, on spider diversity and prey abundance,

• H4_NMDS.R: script for testing hypothesis 4 part 1, on community composition,

• H4_CWM.R. script for testing hypothesis 4 part 2, on community weighted mean (CWM) traits shift.

  
  

File: species_data_raw.zip

Data source note

Species trait and phylogenetic tree information was compiled and harmonized with our species, from previously published sources (Heidrich et al. 2023, Müller et al. 2022). This sources were cited both in the manuscript and within README (see at the end of the page).

Description: 

Data: spider_traits_analysis.csv:

This is a processed spider trait dataset used in all trait-based analyses reported in this study.

Rows

Each row represents one spider species.

Key column

species: species name used to match taxa across community_data.csv and extended_spidertree.tre

Terminology:

Trait variables

Habitat stratum traits (binary: 1 = yes, 0 = no)

Variables beginning with "stratum_" describe the main forest strata in which a species forages:

• stratum_ground
• stratum_herb
• stratum_shrub
• stratum_trunk
• stratum_canopy

Web strategy traits (binary: 1 = yes, 0 = no)

Variables beginning with "web_" describe the foraging/web type of each species:

• web_tangles = tangle web with stopping threads
• web_hunter = active hunter (no web)
• web_horizontalB = horizontal web (bottom)
• web_horizontalT = horizontal web (top)
• web_vertical = vertical web

Dispersal trait

• dispersal: aerial dispersal ability (1 = high dispersal ability, 0 = otherwise)

Morphological traits, they** all measured in millimeter:

• body_size_lit: mean body length from literature sources
• opisthosoma_breadth: residual opisthosoma breadth
• prosoma_breadth: residual prosoma breadth
• leg_length: residual leg length
• fang_length: residual fang length

Missing values

Missing values are coded as NA.

Data: extended_spidertree.tre

Phylogenetic tree file in Newick format containing spider species used in the phylogenetic and functional-phylogenetic diversity analyses reported in this study.

File content

• Tip labels = spider species names
• Branch lengths = phylogenetic distances among taxa
• Internal nodes = inferred shared ancestry relationships

Notes

• Species names follow the naming convention used in the community and trait datasets (underscores instead of spaces).
• Some missing taxa were matched or added at the genus level during the analysis workflow, as documented in the R script.

Code/software

R is required to reproduce all analyses conducted in this study

All .csv files can be open using Microsoft Excel software.

The .tree file is provided as plain text and can be opened in standard phylogenetic software or R packages such as ape, phytools, or picante.

Access information

Other publicly accessible locations of the data:

• 
  

The trait and phylogenetic tree information were originally derived from the following sources:

• Heidrich, L., Brandl, R., Ammer, C., Bae, S., Bässler, C., Doerfler, I., Fischer, M., Gossner, M. M., Heurich, M., Heibl, C., Jung, K., Krzystek, P., Levick, S., Magdon, P., Schall, P., Schulze, E.-D., Seibold, S., Simons, N. K., Thorn, S., … Müller, J. (2023). Effects of heterogeneity on the ecological diversity and redundancy of forest fauna. Basic and Applied Ecology, 73, 72–79. https://doi.org/10.1016/j.baae.2023.10.005
• Müller, J., Brandl, R., Cadotte, M. W., Heibl, C., Bässler, C., Weiß, I., Birkhofer, K., Thorn, S., & Seibold, S. (2022). A replicated study on the response of spider assemblages to regional and local processes. Ecological Monographs, 92(3), e1511. https://doi.org/10.1002/ecm.1511