CENTURY ecosystem model application for quantifying vegetation dynamics inshifting cultivation areas: A case study from Rampa Forests, Eastern Ghats(India)

In India, slash and burn agriculture is one of the major factors contributi ng to deforestation, especially in the hilly north-eastern region and Easte rn Ghats. Studies on vegetation dynamics associated with slash and burn agr icultural practices have been intensively studied in the north-eastern part of India. These have covered semi-evergreen/evergreen vegetation, but simi lar studies on tropical mixed dry deciduous ecosystems are not as common. I n the present study, we used the CENTURY ecosystem model to study vegetatio n dynamics in shifting cultivation areas on the mixed dry deciduous forests covering the Eastern Ghats of India, The site-specific parameters, tempera ture, precipitation, biomass and nutrient pools were used, and, by collecti ng information from local management practices, a 12-year shifting cultivat ion cycle during a 70-year period from 1960 to 2030 was simulated. CENTURY estimated a total loss of 239 tonnes carbon (tC) in soil organic matter ove r the simulation period, and the total nitrogen content of the soil organic matter showed an initial increase followed by a decline (344.3 g m(2) duri ng 1960 to less than 318.3 g m(2) during 2030). CENTURY estimated that 66 t C ha(-1) would be lost from the forest system, reducing the initial forest system carbon level from 118.5 tC ha(-1). An increase in productivity from 0.49 tC ha(-1) during 1960 to 1.2 tC ha(-1) during the initial forest slash and burn in 1962 was observed, but thereafter productivity declined to 0.7 tC ha(-1) during the year 2030. Results obtained in other studies of simil ar types of agricultural practices are also reviewed.