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

Abstract

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. This dataset is used to explore the relative influence of horizontal, vertical and seasonal drivers of arthropod distribution in this forest. We considered arthropod abundance, observed and estimated species richness, additive decomposition of species richness, multiplicative partitioning of species diversity, variation in species composition, species turnover and guild structure as components of diversity. At the scale of our study (2km of distance, 40m in height and 400 days), the effects related to the vertical and seasonal dimensions were most important. Most adult arthropods were collected from the soil/litter or the upper canopy and species richness was highest in the canopy. We compared the distribution of arthropods and trees within our study system. Effects related to the seasonal dimension were stronger for arthropods than for trees. We conclude that: (1) models of beta diversity developed for tropical trees are unlikely to be applicable to tropical arthropods; (2) it is imperative that estimates of global biodiversity derived from mass collecting of arthropods in tropical rainforests embrace the strong vertical and seasonal partitioning observed here; and (3) given the high species turnover observed between seasons, global climate change may have severe consequences for rainforest arthropods.

Opposite latitudinal patterns for bird and arthropod predation revealed in experiments with differently colored artificial prey

“…Model caterpillars placed in tropical forest understoreys sometimes showed no signs of bird predation (Sam et al, ). These results may be at least partly due to the higher abundance of natural prey in the top canopy than in the understorey of a tropical forest (van Bael et al, ; Basset et al, ).…”

Consistent patterns of high alpha and low beta diversity in tropical parasitic and free‐living protists

“…These biogeographical patterns of high alpha diversity within forests and low beta diversity between forests were consistent for both the parasitic Apicomplexa and the largely free‐living Cercozoa and Ciliophora, even though they have different ecological functions and different dispersal modes. The apicomplexan patterns can be explained by them mirroring the patterns of their animal hosts: Arthropod biogeographic patterns, at least for the herbivores, are themselves partially driven by their host plants (Basset et al., ; Novotny et al., ). Apicomplexan patterns should follow the animals if they are largely host‐specific, although little is known of their biology in the Neotropics except for some Haemospororida, such as Plasmodium (Fecchio et al., ; Svensson‐Coelho, Loiselle, Blake, & Ricklefs, ), which accounted for only a small fraction of Apicomplexa here.…”

“…Arthropod biogeographic patterns, at least for the herbivores, are themselves partially driven by their host plants (Basset et al, 2015;Novotny et al, 2007). Apicomplexan patterns should follow the animals if they are largely host-specific, although little is known of their biology in the Neotropics except for some Haemospororida, such as…”

Persistent patterns of high alpha and low beta diversity in tropical parasitic and free-living protists

“…The biogeographical patterns of high alpha diversity within forests and low beta diversity between forests were persistent for both the parasitic Apicomplexa and the free-living Cercozoa and Ciliophora, even though they have different ecological functions and different dispersal modes. The apicomplexan patterns can be explained by them mirroring the patterns of their animal hosts: arthropod biogeographic patterns, at least for the herbivores, are themselves partially driven by their host plants (Basset et al 2015, Novotny et al 2007). Apicomplexan patterns should follow the animals if they are largely host-specific, although little is known of their biology in the Neotropics except for some Haemospororida, such as Plasmodium (Fecchio et al 2017, Svensson-Coelho et al 2016, which accounted for only a small fraction of Apicomplexa here.…”