Rainforest conversion and expansion of plantations in tropical regions is associated with changes in animal communities and biodiversity decline. In soil, Collembola are one of the most numerous invertebrate groups that control microbial processes and support arthropod predators. Despite that, information on the impact of changes in land use in the tropics on species and trait composition of Collembola communities is very limited. We investigated the response of Collembola to the conversion of rainforest into rubber agroforest (‘junge rubber’), rubber and oil palm plantations in Jambi province (Sumatra, Indonesia), a region that experienced one of the strongest deforestation globally during the last decades. Collembola from litter and soil layers were collected in 2013 and 2016 using heat extraction. In the litter layer, density and species richness in plantation systems declined by 25-38% and 30-40%, respectively, compared to rainforest. By contrast, in the soil layer, density, species richness and trait diversity of Collembola were only slightly affected by land-use change contrasting the response of many other animal groups. Species and trait composition of Collembola communities in litter and soil layers differed between all land-use systems. Water content and pH were identified as main factors related to the differences in species and trait composition both in litter and soil layers, followed by the density of micro- and macropredators. Dominant Collembola species in rainforest and jungle rubber were characterized by small body size, absence of furca and absent or intense pigmentation, while in plantations larger species with long furca and diffuse or patterned coloration were more abundant. The trait-based responses were similar to those observed in Collembola from temperate regions and to those in a similar study on spiders at our study sites. Overall, land-use change negatively affected Collembola communities in the litter layer, but only little affected Collembola communities in soil. Several pantropical Collembola genera (i.e., Isotomiella, Pseudosinella and Folsomides) dominated across land-use systems, reflecting their high environmental adaptability or efficient dispersal calling for studies on their ecology and genetic diversity. The decline in species richness and density of litter-dwelling Collembola with the conversion of rainforest into plantation systems calls for management practices mitigating negative effects of the deterioration of the litter layer in rubber but in particular in oil palm plantations.

Animals were extracted by heat for three days and stored in 70% ethanol until further processing. Environmental variables were measured in composite samples of each litter and soil (five cores per plot within a radius of ca. 2 m around the soil animal sample), including abiotic factors (pH, water content, C:N ratio) and biotic factors (microbial community composition in litter and soil as indicated by phospholipid fatty acids. Litter and soil pH (CaCl₂) was measured using a digital pH meter. Aliquots of litter and soil material were dried at 65 °C for 72 h, milled and analyzed for total C and N concentrations using an elemental analyzer (Carlo Erba, Milan, Italy). Amount of litter and water content of litter and soil were determined gravimetrically. All collected animals were sorted to high rank taxonomic groups and identified using traits analysis.

Collembola were sorted into morphogroups under a dissecting microscope (Zeiss, Stemi 508) at 50x magnification based on basic morphlogical characters (body shape, morphology of furca, antennae, and number of eyes). A number of individulas of each morphogroup from each sample were subsequently cleared with Nesbitt solution on a heating plate (50^⁰C) for 3-10 min. Then, the animals were mounted on slides with Hoyer’s solution (for details see Glime and Wagner, 2017). Collembola were identified to species level using a compound microscope (Axiovert 35, Zeiss, Jena, Germany) at maximum 400× magnification, using the checklist for Indonesian Collembola (Suhardjono et al., 2012) and additional articles containing keys for Collembola of southeast Asia, particularly Indonesia (Potapov and Starostenko, 2002; Potapov, 2012; Mateos and Greenslade, 2015). Along with the identification, each species was described using a set of morphological traits. The same selected set of traits was used for each species across land-use systems for statistical analysis, including: presence/absence of empodial appendage, sucking/chewing mouthpart, presence/absence of post-antennal organ (PAO), presence/absence of scales, elongated/normal abdomen IV, elongated/spherical abdomen, separate/fused abdominal segments, presence/absence of furca, straight/curved and short/long furca, presence/absence of pigmentation, diffuse/patterned and intensive/light pigmentation, normal/modified antennae, small/medium/large body size.

These data are about species composition and trait composition of Collembola from Indonesia (including litter and soil Collembola in two sampling years, 2013 and 2016). These data are available in excel and can be use for analyses, for example with R analyses. The data about environmental condition (biotic and abiotic) also were provided for the analyses.