Abstract
The area around Jangkok watershed has changed, dividing it into some land use systems. This research aimed to study the effect of plant species diversity on C- stocks, and to analyse the characteristics of land use system s based on their similar ity . The observations were carried out on 18 plots representing six land use systems in Jangkok watershed (Lombok Island) i.e. primary forest (PF), disturbed forest (DF), Mahogany - woodlot (MW), candlenut - agroforestry (CA), multistrata - agroforestry (MA), and simple - agroforestry (SA). The species diversity level was measured using Shannon-Weiner diversity index , while C- stocks according to the method of RaCSA ( Rapid Carbon Stock Appraisal ) . Results showed that forest conversion to agricultural land use s reduced the number and density of the species , average w ood density and tree basal area . The PF represented the highest biodiversity index (3.46), while the other land uses were categorised in medium and low. Largest C-stock was found in PF and in (30 years old) of MW average d of 500 Mg ha - 1 , while the lowest was in S A of 68 Mg ha - 1 , while in other land uses wa s 219 Mg ha - 1 . The quantity of C- stock was not related to species diversity and its density , but closely related (p of tree (R 2 =0.84), basal area of all sizes tree (R 2 =0.86), and with the basal area of big trees ( diameter > 30 cm ) (R 2 =0.71). Based on the number and species density, agroforestry system ( MA and CA ) resembled the characteristics of natural forest ( DF and PF ) . /spanEN-GBspan style=