LAJU RESPIRASI TANAH DAN AKTIVITAS DEHIDROGENASE DI KAWASAN LAHAN GAMBUT CAGAR BIOSFER GIAM SIAK KECIL-BUKIT BATU

Abstract

Giam Siak Kecil-Bukit Batu Biosphere Reserve (GSK-BB) is one of the peatland areas in Riau province which consist of conservation and production areas. Most of these areas have been converted to oil palm plantations, timber plantations (HTI), agricultural and settlement areas. This research was aimed to analyze the impact of land use changes on soil physical-chemical characteristics, the number of bacterial cells, soil respiration rate, and soil dehydrogenase activity. Soil sample was taken from 6 different locations, primary forest as control, secondary forest, rubber plantation, rubber forest, andoil palm plantation (3 and 12 years old). The result indicated that the soil temperature, soil dry weight, water content, soil bulk density and pH, range from 28.25-31.250C, 15.1-36.1%, 63.9-84.9%, 0.10-0.34 g/cm3, and 3.5, respectively. The number of copiotrophic bacterial cells ranges from 3.0x105-5.4x105 CFU/g soil. The number of oligotrophic bacterial cells ranges from 3.3x105-4.6x105CFU/g soil. Furthermore, soil respiration rate ranges from 40.87-81.09 mg CO2/g soil/h for soil without glucose and 70.96-119.19 mg CO2/g soil/hfor glucose enriched soil. Soil dehydrogenase activity ranges from 16.25-158.20 μg formazan/g dry weight soil/h. The results also showed that land use changes influence soil respiration rate and soil dehydrogenase activity, therefore those parameters tested can serve as indicators for soil quality on peatland.