Indonesian soil and litter Collembola species and trait matrix with environmental data

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.