DOI: 10.5061/dryad.7h44j101f
title: Trait overdispersion in dragonflies reveals the role and drivers of competition in community assembly across space and season

description: Our understanding of how biotic interactions influence animal community
 assembly is largely restricted to local systems due to the difficulty of
 obtaining ecologically meaningful assemblage data across large spatial
 extents. Here, we used thousands of spatio-phenologically high-resolution
 assemblages across three distinct European regions together with a
 functional diversity approach to understand community assembly of
 dragonflies and damselflies (Odonata), an insect group characterized by a
 pronounced competitive reproductive biology. We found that adult
 dragonfly, but not damselfly, assemblages were consistently composed of
 species morphologically more different than expected by chance based on
 the traits that enhance their inter-specific reproductive encounters.
 These results provide consistent evidence for the role of competition in
 the assembly of animal communities, which we interpret is most likely
 caused by the territorial reproductive biology of dragonflies. Support for
 competition varied both spatially and seasonally following theoretical
 expectations, as it was strongest in locations and seasonal moments with
 low thermal stress (i.e. warm conditions) and high niche packing. Our
 study illustrates how spatio-temporal diversity patterns arise from
 variation in assembly processes.
description: # Trait overdispersion in dragonflies reveals the role and drivers of
 competition in community assembly across space and season
 There are 7 tables
 describing assemblages of dragonflies and damselflies in three study
 systems: Great Britain, Bavaria and Catalonia. All tables named "main
 analysis" describe assemblages built for the main analysis of the
 manuscript, using the parameters: *resSp* = 0.1 km, *resPh* = 30, *resTem*
 = 3, *samEf* = 4, *samCov* = 80, *Smin* = 4. Note that these parameters
 are described in the manuscript. * "Assemblages mainAnalysis
 FD.csv" decribes functional diversity of assemblages of Anisoptera
 and Zygoptera, for the three systems and based on both multitrait-FD and
 body size-FD. The tables: * "Assemblages mainAnalysis
 multitraitFD-env Anisoptera.csv" * "Assemblages mainAnalysis
 multitraitFD-env Zygoptera.csv" Contain multitrait FD for the three
 systems, respectively for Anisoptera and Zygoptera, and contain
 environmental data on the 10-year average temperature in the location and
 day of the year of the assemblage. The tables called phenoAnalysis
 describe assemblages built for the phenological analysis of the manuscript
 using the parameters: *resSp* = 0.1 km, *resPh* = 14 and *resTem* = 0,
 *samEf* = 4, *samCov* = 80, *Smin* = 3 There are four different files
 separated for Anisoptera and Zygoptera, and for multitrait FD and body
 size FD. ## Description of the data and file structure Description of
 variables within the tables: * Dataset: The study system of the
 assemblage. GB= Great Britain, Bavaria = Bavaria, Catalonia = Catalonia. *
 group: The taxonomic group (suborder) of the assemblage. Either Anisoptera
 (dragonflies) or Zygoptera (damselflies). * Day: average day of the year
 (1-365) of the observations that constitute the asemblage. * Lat:
 Latitude* * Long: Longitude* * Trait_set: Trait set used to measure FDses.
 Either based uniquely on body size (bodysizeFD) or a multi-trait measure
 based on body size, abdomen length, wing length, and the three RGB colour
 channels (multitraitFD). * FDis_SES: Standard effect size of functional
 diversity (FDses), measured using the metric FDis. *
 SES_cwm.body_volume.cm3: Standard effect size of community weighted means
 of body volume. * Forest: Proportion of forest landcover in the ~1x1 km
 cell of the assemblage. Calculated as the proportion of ~100x100m cells of
 forest landcover within a ~1x1km cell. * Temp: Summer temperature in the
 ~1x1 km cell of the assemblage. Units are degrees Celsius (°C). * tas: Air
 temperature in the day of the year and ~1x1 km cell of the assemblage.
 Units are kelvins (K). For Forest, Temp, and tas variables, NA represents
 missing values arising from methodological limitations when processing
 raster data. *Note that Lat and Long are described in different reference
 systems depending on the dataset: * GB= EPSG:27700 * Bavaria= EPSG:31468 *
 Catalonia = EPSG:32631 ## Sharing/Access information This data is derived
 from the following sources: * Databases of occurrence records were
 obtained: for Great Britain (GB) from the *British Dragonfly society*, for
 Bavaria from *Bayerische Artenschutzkartierung*
 ([www.lfu.bayern.de/natur/artendaten](http://www.lfu.bayern.de/natur/artendaten) and for Catalonia from *Institució Catalana d’Història Natural* (). * Temperature is derived from: [https://chelsa-climate.org/chelsa-w5e5-v1-0-daily-climate-data-at-1km-resolution ](https://chelsa-climate.org/chelsa-w5e5-v1-0-daily-climate-data-at-1km-resolution"Karger)"Karger, D. N., Lange, S., Hari, C., Reyer, C. P. O. and Zimmermann, N. E. 2022. CHELSA-W5E5 v1.0: W5E5 v1.0 downscaled with CHELSA v2.0." * Summer temperature corresponds to Bio 10, from CHELSA V1.2. "Karger, D. N., Conrad, O., Böhner, J., Kawohl, T., Kreft, H., Soria-Auza, R. W., Zimmermann, N. E., Linder, H. P. and Kessler, M. 2017. Climatologies at high resolution for the earth’s land surface areas. - Sci Data 4: 170122." * Forest is derived from