Data from: Linking size spectrum, energy flux and trophic multifunctionality in soil food webs of tropical land-use systems

1. Many ecosystem functions depend on the structure of food webs, which
heavily relies on the body size spectrum of the community. Despite that,
little is known on how the size spectrum of soil animals responds to
agricultural practices in tropical land-use systems and how these
responses affect ecosystem functioning. 2. We studied land-use induced
changes in belowground communities in tropical lowland ecosystems in
Sumatra (Jambi province, Indonesia), a hotspot of tropical rainforest
conversion to rubber and oil palm plantations. The study included ca.
30,000 measured individuals from 33 high-order taxa of meso- and
macrofauna spanning eight orders of magnitude in body mass. Using
individual body masses we calculated the metabolism of trophic guilds and
used food-web models to calculate energy fluxes and infer ecosystem
functions, such as decomposition, herbivory, primary and intraguild
predation. 3. Land-use change was associated with reduced abundance and
taxonomic diversity of soil invertebrates, but strong increase in total
biomass and moderate changes in total energy flux. These changes were due
to increased biomass of large-sized decomposers in soil, in particular
earthworms, with their share in community metabolism increasing from 11%
in rainforest to 59-76% in jungle rubber, and rubber and oil palm
plantations. Decomposition, i.e. the energy flux to decomposers, stayed
unchanged, but herbivory, primary and intraguild predation decreased by an
order of magnitude in plantation systems. Intraguild predation was very
important, being responsible for 38% of the energy flux in rainforest
according to our model. 4. Conversion of rainforest into monoculture
plantations is associated by an uneven loss of size classes and trophic
levels of soil invertebrates resulting in sequestration of energy in
large-sized primary consumers and restricted flux of energy to higher
trophic levels. Pronounced differences between rainforest and jungle
rubber reflect sensitivity of rainforest soil animal communities to
moderate land-use changes. Soil communities in plantation systems
sustained high total energy flux despite reduced biodiversity. The high
energy flux into large decomposers but low energy fluxes to other trophic
guilds suggests that trophic multifunctionality of belowground communities
is compromised in plantation systems.