Species traits and habitatsin springtail communities : a 1 regional scale study

1 Although much work has been done on factors patterning species trait assemblages in 2 emblematic groups such as plants and vertebrates, more remains to be done in 3 belowground invertebrate species. In particular,relationships between species traits and 4 habitat preferences are still a matter of debate. Springtails were sampled in a 5 heterogeneous landscape centered on the Sénart forest, near Paris (northern France), 6 embracingthe largest possible array of five environmental gradients (humus forms, 7 vegetation, moisture, vertical strata, and seasons) over which Collembola are known to 8 be distributed. Distances between samples varied from a few cm to several km. 9 Canonical correspondence analysis using species (128) as observations and species trait 10 attributes (30) and habitat indicators (82) as dependent and independent variables, 11 respectively, allowed to discern whether species habitats and species trait assemblages 12 were related and which trends could be found in trait/environment relationships. It was 13 concluded that, within the studied area, species habitatswere significantly associated 14 with species trait assemblages. The main gradient explaining the distribution of species 15 traits combined the vertical distribution of habitats (from the mineral soil to plant aerial 16 parts), and the openness of the environment, i.e. a complex of many ecological factors. 17 In the ecological traits of Collembola, this gradient corresponded to anincreasing 18 contribution of sensory and locomotory organs, bright color patterns, size and sexual 19 reproduction, all attributes associated with aboveground life under herbaceous cover. 20 Another important, although secondarycontrast concerned traits associated with habitats 21 far from soil but concealed (corticolous vs all other habitats). Soil acidity and water did 22 not contribute significantly to trait distribution, at least within the limits of our database.