Arthropod Distribution in a Tropical Rainforest: Tackling a Four Dimensional Puzzle.

Quantifying the spatio-temporal distribution of arthropods in tropical rainforests represents a first step towards scrutinizing the global distribution of biodiversity on Earth. To date most studies have focused on narrow taxonomic groups or lack a design that allows partitioning of the components of diversity. Here, we consider an exceptionally large dataset (113,952 individuals representing 5,858 species), obtained from the San Lorenzo forest in Panama, where the phylogenetic breadth of arthropod taxa was surveyed using 14 protocols targeting the soil, litter, understory, lower and upper canopy habitats, replicated across seasons in 2003 and 2004.

Arthropod diversity in a tropical forest.

Most eukaryotic organisms are arthropods. Yet, their diversity in rich terrestrial ecosystems is still unknown. Here we produce tangible estimates of the total species richness of arthropods in a tropical rainforest.

Spatial and environmental factors contributing to patterns in arboreal and terrestrial oribatid mite diversity across spatial scales.

Understanding the conditions under which species traits, species-environment relationships, and the spatial structure of the landscape interact to shape local communities requires quantifying the relative contributions of space and the environment on community composition. Using analogous sampling of arboreal and terrestrial oribatid mite communities across a large spatial scale in a temperate rainforest, we quantified the variation in oribatid mite community structure relating to environmental and spatial factors, and tested whether terrestrial and arboreal communities demonstrated a difference in their patterns of community composition based on the assumption of differences in dispersal potential. The expectation that terrestrial oribatid mite communities are spatially structured while arboreal communities are environmentally structured was supported by our analyses at the level of variation in beta diversity, but not by assessing beta diversity itself.

An experimental assessment of biodiversity and species turnover in terrestrial vs canopy leaf litter.

Forest canopies support diverse assemblages of free-living mites. Recent studies suggest mite species complementarity between canopy and terrestrial soils is as high as 80-90%. However, confounding variation in habitat quality and resource patchiness between ground and canopy has not been controlled in previous comparative studies.