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Little is known regarding how trophic interactions shape community assembly in tropical forests. Here we assess multi-taxonomic community assembly rules using a rare standardized coordinated inventory comprising exhaustive surveys of five highly-diverse taxonomic groups exerting key ecological functions: trees, fungi, earthworms, ants and spiders. We sampled 36 1.9-ha plots from four remote locations in French Guiana including precise soil measurements, and we tested whether species turnover was coordinated among groups across geographic and edaphic gradients. All species group pairs exhibited significant compositional associations that were independent from soil conditions. For some of the pairs, associations were also partly explained by soil properties, especially soil phosphorus availability. Our study provides evidence for coordinated turnover among taxonomic groups beyond simple relationships with environmental factors, thereby refining our understanding regarding the nature of interactions occurring among these ecologically important groups.

1. Arthropods represent most of global biodiversity, with the highest diversity found in tropical rain forests. Nevertheless, we have a very incomplete understanding of how tropical arthropod communities are assembled. 2. We conducted a comprehensive mass sampling of arthropod communities within three major habitat types of lowland Amazonian rain forest, including terra firme clay, white-sand and seasonally flooded forests in Peru and French Guiana. We examined how taxonomic and functional composition (at the family level) differed across these habitat types in the two regions. 3. The overall arthropod community composition exhibited strong turnover among habitats and between regions. In particular, seasonally flooded forest habitats of both regions comprised unique assemblages. Overall, 17.7% (26 of 147) of arthropod families showed significant preferences for a particular habitat type. 4. We present a first reproducible arthropod functional classification among the 147 taxa based on similarity among 21 functional traits describing feeding source, major mouthparts and microhabitats inhabited by each taxon. We identified seven distinct functional groups whose relative abundance contrasted strongly across the three habitats, with sap and leaf feeders showing higher abundances in terra firme clay forest. 5. Our novel arthropod functional classification provides an important complement to link these contrasting patterns of composition to differences in forest functioning across geographical and environmental gradients. This study underlines that both environment and biogeographical processes are responsible for driving arthropod taxonomic composition while environmental filtering is the main driver of the variance in functional composition.

The genus Pseudopoda, Jager, 2000 is revised for Yunnan Province, China. Fifteen new species are described: Pseudopoda sinapophysis sp. n., Pseudopoda interposita sp. n., Pseudopoda gongschana sp. n., Pseudopoda saetosa sp. n., Pseudopoda contentio sp. n., Pseudopoda amelia sp. n., Pseudopoda yinae sp. n., Pseudopoda roganda sp. n., Pseudopoda cangschana sp. n., Pseudopoda shuqiangi sp. n., Pseudopoda daliensis sp. n., Pseudopoda obtusa sp. n., Pseudopoda rivicola sp. n., Pseudopoda digitata sp. n., Pseudopoda contraria sp. n. The male of Pseudopoda bibulba (Xu and Yin, 2000) and the female of Pseudopoda spiculata (Wang, 1990) are described for the first time. Pseudopoda yunnanensis (Yang and Hu, 2001) comb. n. is transferred from the genus Sinopoda Jager, 1999. Limits of species groups in Pseudopoda are discussed. Some characters are confirmed to be dependent on size of the spider (e.g., leg formula, ratio between head region and width of posterior eye row).

A new species of Heteropodinae is described from northern Laos: Heteropoda dagmarae sp. nov. From genital as well as somatic characters it seems to be closely related to Heteropoda javana (Simon 1880) from Sumatra and Java. A javana species-group is proposed within Heteropoda Latreille 1804 by means of these two species and several undescribed species.

Pseudopoda fissa sp. nov. is described from Vietnam (male holotype). The new species belongs to the schwendingeri-group, previously known exclusively from northern Thailand. It is the first time that a representative of the genus Pseudopoda is recorded from Vietnam.

The need for an updated list of spiders found in French Guiana rose recently due to many upcoming studies planned. In this paper, we list spiders from French Guiana from existing literature (with corrected nomenclature when necessary) and from 2142 spiders sampled in 12 sites for this baseline study. Three hundred and sixty four validated species names of spider were found in the literature and previous authors' works. Additional sampling, conducted for this study added another 89 identified species and 62 other species with only a genus name for now. The total species of spiders sampled in French Guiana is currently 515. Many other Morphospecies were found but not described as species yet. An accumulation curve was drawn with seven of the sampling sites and shows no plateau yet. Therefore, the number of species inhabiting French Guiana cannot yet be determined. As the very large number of singletons found in the collected materials suggests, the accumulation curve indicates nevertheless that more sampling is necessary to discover the many unknown spider species living in French Guiana, with a focus on specific periods (dry season and wet season) and on specific and poorly studied habitats such as canopy, inselberg and cambrouze (local bamboo monospecific forest).