Soil organic C stocks are still not at equilibrium more than a decade after conversion.Therefore, losses from mineral soils should be accounted for when rainforests are converted to perennial crops.First, our aim was to quantify total C losses after rainforest conversion to jungle rubber, rubber, and oil palm monocultures.
Soil organic C stocks are still not at equilibrium more than a decade after conversion.Therefore, losses from mineral soils should be accounted for when rainforests are converted to perennial crops.
Third, we investigated net ecosystem productivity (NEP), ecosystem C storage, and SOC dynamics using the balance between biomass C inputs and soil CO efflux.
Finally, we put the yield increase resulting from land-use intensification into perspective with the reduction in ecosystem C storage and biomass production.
We find that rainforest conversion to oil palm plantations leads to the highest ecosystem C storage loss because of the shorter rotation time of oil palm plantations compared to rubber.
Even though most C losses occur aboveground, significant C amounts were lost belowground.
Rainforests in Sumatra converted to jungle rubber, rubber, and oil palm monocultures lost 116 Mg C ha, respectively.
Up to 21% of these carbon losses originated from belowground pools, where soil organic matter still decreases a decade after conversion.
While yield increase enables more agricultural commodities to be produced per surface area, intensive plantations require higher consumption of natural resources such as water and nutrients, and deliver less regulating ecosystem services than natural ecosystems or less intensive land-use types.
Additionally, a high proportion of harvested biomass reduces the C and energy available for heterotrophic organisms in the plantation’s food web, thereby limiting ecosystem services supporting agricultural production.
1), differences were not significant with rubber monocultures.
Nonetheless, oil palm plantation was the only agroecosystem that had a significant decrease in total belowground C storage down to 50 cm depth (sum of coarse roots, fine roots, fine roots necromass, and soil organic C) as compared to rainforest (Supplementary Table 1).