Author : Banaticla, Ma. Regina N.

Summary : Carbon storage of land cover types that represent stages of a common land use system in Brgy. Puting Lupa, Calamba City, at the western margin of the Mt. Makiling Forest Reserve was determined. The land cover types are an open kaingin (cultivated for 1 year), 13- and 22-year-old abandoned kaingins, ipil-ipil (Leucaena leucocephala)-dominated stand, and secondary forest located at the ridges. the C stock in the following pools was measured using field methods: live trees, coarse woody debris, understorey vegetation, standing litter, coarse-and fine roots, and soil up to a 30 cm depth. Deterministic models were used to estimate aboveground tree biomass and coarse woody debris necromass. The open kaingin has the lowest total soil C storage (42.11 Mg/ha), followed by the 22 year old abandoned kaingin (50.74 Mg/ha); secondary forest (57.70 Mg/ha); 13 year old abandoned kaingin (57.83 Mg/ha), and ipil-ipil stand (66.65 Mg/ha). The land cover types, in decreasing order of total C stock are: ipil-ipil stand>secondary forest>22 year old abandoned kaingin>13 year old abandoned kaingin>open kaingin. estimates for C stock and aboveground C accumulation rates (2 Mg/ha/yr for the abandoned kaingins and 2-3 Mg/ha/yr for the ipil-ipil stand) indicate that belowground C storage is less prone to losses from land use and natural disturbances but greater C sequestration will be potentially achieved aboveground.