Vertical root distribution and contribution of coarse roots to the soil carbon pool in lowland rainforest transformation systems on Sumatra, Indonesia
Deforestation and land use change have extremely decreased forest cover in Sumatra. Estimated forest cover decreased from c.37.4 million ha in 1950 to c.13.6 million ha in 2010. Natural rainforest in Sumatra is converted mainly into oil palm (Elaeis guineensis) and rubber (Hevea brasiliensis) plantations at increasing rates. Conversion of forests not only leads to a loss in species diversity, but also has a significant effect on the ecosystems carbon stock. Fine and coarse roots are two important below-ground biomass components and they are known to play an important role in the carbon budget of forests. Fine roots are essential for nutrients and water acquistion of the tree and represent a major tree compartment with respect to annual net primary production. The coarse roots can notably contribute to carbon soil stocks when they become decomposed. The aims of the study are to estimate the biomass of fine and coarse roots, to compare estimates of fine root and coarse root production and related carbon fluxes of different forest types (i.e. forest, jungle rubber, rubber and oil palm plantation at Harapan Forest, Jambi).