DOI: 10.5061/dryad.ffbg79cr6
title: Data from: Island properties dominate species traits in determining plant colonizations in an archipelago system

description: The extrinsic determinants hypothesis emphasizes the essential role of
 environmental heterogeneity in species’ colonization. Consequently, high
 resident species diversity can increase community susceptibility to
 colonizations because good habitats may support more species that are
 functionally similar to colonizers. On the other hand, colonization
 success is also likely to depend on species traits. We tested the relative
 importance of environmental characteristics and species traits in
 determining colonization success using census data of 587 vascular plant
 species collected about 80 years apart from 471 islands in the archipelago
 of SW Finland. More specifically, we explored potential new colonization
 as a function of island properties (e.g., location, area, habitat
 diversity, number of resident species per unit area), species traits
 (e.g., plant height, life-form, dispersal vector, Ellenberg indicator
 values, association with human impact), and species’ historical
 distributions (number of inhabited islands, nearest occurrence). Island
 properties and species’ historical distributions were more effective than
 plant traits in explaining colonization outcomes. Contrary to the
 extrinsic determinants hypothesis, colonization success was neither
 associated with resident species diversity nor habitat diversity per se,
 although colonization was lowest on sparsely vegetated islands. Our
 findings lead us to propose that while plant traits related to dispersal
 and establishment may enhance colonization, predictions of plant
 colonizations primarily require understanding of habitat properties and
 species’ historical distributions.
description: Historical species data from Eklund, O. 1958. Die
 Gefässpflanzenflora beiderseits Skiftet im Schärenarchipel
 Südwestfinnlands. – Bidrag till Kännedom af Finlands Natur och Folk 101:
 1–342. Skult, H. 1960. Om kärlväxtfloran i Korpo, Brunskär, en
 utskärsarkipelag.– Acta Soc. Fauna Flora Fenn. 76: 1–101. Contemporary
 species data collected 1996 2017. For more information contact the author
 MvN.
description: Metadata: 
 outcome Colonization outcome (0=failure, 1=success) Euref_X EUREF-FIN X-coordinate.  Euref_Y EUREF-FIN Y-coordinate.  Euref_X_original EUREF-FIN X-coordinate. Untransformed values. Euref_Y_original EUREF-FIN Y-coordinate. Untransformed values. Residents_per_area_log Number of resident species per unit area.  Area_log Island area.  Buffer_2_km_log Land area within a 2 km buffer around an island. Buffer_5_km_log Land area within a 5 km buffer around an island. Shannon_habitats Shannon's diversity index calculated from the proportional cover of CORINE level 4 land cover types. Convolution Index of island convolution as the perimeter ratio of island and circle of the same area. Limestone Presence of limestone on the island according to Eklund (0=absent, 1=present) Buildings Proportion of built area on an island based CORINE land cover data. Meadow_or_pasture Proportion of meadows and pastures on an island based on CORINE land cover data. Deciduous_forest Proportion of deciduous forests on an island based on CORINE land cover data. Coniferous_forest Proportion of coniferouse forest on an island based on CORINE land cover data. Mixed_forest Proportion of mixed forests on an island based on CORINE land cover data. Scrub Proportion of Scrub on an island based on CORINE land cover data. Sand Proportion of sand on an island based on CORINE land cover data. Open_rock_or_bare_ground Proportion of open roch or and bare ground on an island based on CORINE land cover data. Marsh Proportion of marsh on an island based on CORINE land cover data. Shore_meadow Proportion of shore meadows on an island based on CORINE land cover data. Dist_to_historical_log Distance to the nearest island historically colonized by the focal species. Gowdis_traits Grower distance between  life history traits of the focal species and resident species of the focal island. Historical_total_log Number of islands historically colonized by the focal species. North_limit North limit of distribution of the focal species in Finland Ellenberg_Light Ellenberg's score for light for the focal species. Ellenberg_Temperature Ellenberg's score for temperature for the focal species. Ellenberg_Moisture Ellenberg's score for moisture for the focal species. Ellenberg_Reaction Ellenberg's score for soil reaction (pH) for the focal species. Ellenberg_Nitrogen Ellenberg's score for nitrogen for the focal species. Eklund_culture Eklunds score for focal species affinity to human modified habitats. Life_cycle Life cycle length for the focal species. Life_form Life form of the focal species. SLA Specific leaf area of the focal species. Plant_height_log Maximum height of the focal species. Dispersal_vector Dispersal vector of the focal species. Seed_bank Seed bank longevity of the focal species. Seed_mass_log Seed mas of the focal species. Pollen_vector Pollen vector of the focal species. Apomictic Apomictic reporduction of the focal species. Veg_repr Vegetative reproduction of the focal species. spp.name Focal species name. holmkod Focal island code. Family Focal species family. Genus Focal species genus.