Rainforest conversion to plantations fundamentally alters energy fluxes
and functions in canopy arthropod food webs
Abstract
Tropical rainforests around the world are rapidly converted into cash
crop agricultural systems. The associated massive losses of plant and
animal species lead to changes in arthropod food webs and the energy
fluxes therein. These changes are poorly understood, in particular in
the extremely biodiverse canopies of tropical ecosystems. Using canopy
fogging followed by stable isotope and energy flux analyses, we show
that land-use conversion from rainforest to rubber and oil palm
plantations not only causes a drastic reduction in energy fluxes of up
to 75%, but also shifts fluxes among trophic groups. While rainforest
featured high levels of both herbivory and algae-microbivory, and a
balanced ratio of herbivory to predation, relative fluxes were shifted
towards predation in rubber and towards herbivory in oil palm
plantations, indicating profound shifts in ecosystem functioning. Our
results highlight that the ongoing loss of animal biodiversity and
biomass in tropical canopies degrades animal-driven functions and
restructures canopy food webs.