MICROCOSMIC STUDY ON HETEROTROPHIC CO2 EMISSION FROM TROPICAL PEAT AS RELATED TO WATER TABLE MODIFICATION

ABSTRACT: A microcosmic experiment was conducted to estimate CO2 emission from peat soils. Two treatments, peat humification levels (F = Fibric, H = Hemic, S = Sapric) and water levels (G0 = 10 cm; G1= 0 cm; G2 = -10 cm; G3 = -20 cm), were tested and arranged according to factorial randomized complete block design (RCBD) with 3 replicates. Current study revealed that CO2 emission was significantly affected (p<0.01) by peat humification levels and water levels. The sapric peat emitted significantly higher CO2 (696.69 b ± 43.95 mg CO2 g-1 peat d-1) than hemic (504.62 a ± 105.72 mg CO2 g-1 peat d-1)and fibric (492.56 a ± 90.69 mg CO2 g-1 peat d-1)peats. Decreases in water level shifted anaerobic condition into aerobic condition, causing significant increases in CO2 emission. Regardless of peat humification levels, CO2 emission and water table depth in current study showed a nonlinier relationship. It seems that a threshold water tables for enhanced CO2 emissions was within the range of -10 to -20 cm below peat surface. Keywords : microcosmic, peat, humification, CO2 emission. ABSTRAK (Indonesian): Tujuan percobaan skala mikrokosm ini adalah untuk estimasi emisi CO2 dari tanah gambut. Pengaruh 2 (dua) perlakuan, yaitu tingkat humifikasi gambut (F = Fibrik, H = Hemik, S = Saprik) dan tinggi muka air (G0 = 10 cm; G1= 0 cm; G2 = -10 cm; G3 = -20 cm), disusun menurut Rancangan Acak Lengkap Faktorial (RALF) dengan 3 (tiga) ulangan. Hasil penelitian menunjukkan bahwa perlakuan tingkat humifikasi gambut dan tinggi muka air mempengaruhi emisi CO2 secara nyata (p