Carbon storage of land cover types in a shifting cultivation system and a secondary forest in Barrio Puting Lupa, Calamba City at the western margin of Mt. Makiling was determined. The cultivated land cover types were a one-year-old cropped field, 13- and 22 year-old forest fallows, and an ipil-ipil- dominated stand. The following C pools were measured using field and indirect methods: live trees, coarse woody debris, understorey vegetation, standing litter, roots, and soil up to a 30 cm depth. New biomass equations developed from secondary data from the Philippines was used to estimate live tree biomass. Estimates for total C density in each land cover type were 66.09 Mg ha-1 for the 1-year-old cropped field; 94.54 Mg ha-1 for the 13-year-old fallow; 100.63 Mg ha-1 for the 22-year-old fallow; 129.95 Mg ha-1 for the ipil-ipil stand, and 102.07 Mg ha-1 for the secondary forest. Belowground C storage had equal or greater importance than aboveground C in all land cover types. The main features of the land use system adopted by farmers in the study were typical of traditional shifting cultivation systems in the humid tropics. Land use analysis indicates the adequateness of the fallow period for recovery of short-term C losses from clearing and cultivation, and that a potential net gain in total system C stocks (mainly aboveground) can occur if the direction of land use continues to shift towards permanent tree-based systems, with adequate protection of regenerating lands.
Publication year
2006
Authors
Language
English
Keywords
biomass, fallow, soil organic matter, carbon storage, woody, vegetation
Geographic
Philippines
