Carbon Stocks Assessment of Secondary Tropical Forest in Mt. Makiling Forest Reserve, Philippines

Lasco, R.D., I.Q. Guillermo, R.V.O. Cruz, N.C. Bantayan and F.B. Pulhin.  2001.  J of Tropical Forest Sci.

Tropical forests are important sources and sinks of carbon (C).  However, there is limited information on the ability of tropical forests to store and sequester C.  The study aimed to quantify the C stocks of a secondary forest formation in Mt. Makiling Forest Reserve, Philippines.  The results showed that total biomass (above and below-ground) of the forest was 576 Mg/ha with an annual tree biomass accumulation of 12 Mg/ha/yr.  At an average of 43% C content of biomass, the total C stocks was 418 Mg C/ha including soil organic C (SOC) which comprised about 40% of the total C sequestration rates were estimated at 5 Mg C/ha/yr.  Some important implications of the results were discussed.

Carbon Stock Assessment of Two Agroforestry Systems in a Tropical Forest Reserve in the Philippines

Lasco, R.D., R.F. Sales, R. Extrella, S.R. Saplaco, A.S.A. Castillo, R.V.O. Cruz, and F.B. Pulhin.  2001.  The Philippine Agriculturist, 84(4):401-407.

Carbon dioxide is the most abundant greenhouse gas (GHG) that causes global warming.  Thus, land uses such as an agroforestry system have a significant role in  moderating climate change since they can be sources and sinks of carbon.  The aim of the study was to generate data on the carbon stocks of two agroforestry systems, specifically a Gmelina arborea-Theobroma cacao multistorey system and an alley cropping system with Gliricidia sepium hedges at the agroforestry research and demonstration area inside a forest reserve in Southern Luzon, Philippines.

The multistorey system had a mean biomass of 258 Mg C ha^-1 and a carbon density of 185 Mg C ha^-1.  Carbon was stored in the brious pools in the following order of magnitude: soil > tree biomass (above-ground) > necromass > understorey vegetation > roots.  The Gliricidia hedgerow had a biomass desity of 3.8 Mg C ha^-1, of which 92 Mg ha^-1 was in the soil. 

Carbon Storage Capacity of Agricultural and Grassland Ecosystems in a Geothermal Block

Lales, J.S., R.D. Lasco and I.Q. Guillermo.  2001.  The Philippine Agriculturist.

Agricultural and grassland ecosystems in the geothermal block managed by the Philippine National Oil Company in Leyte, Philippines were investigated to generate indicative estimates of the carbon storage capacity of major crops and dominant grass species.  Wetland rice, sugarcane, banana and coconut showed highly contrasting C storage capacities.  Wetland rice and ratoon sugarcane stored 3.1 and 13.1 t C ha^-1, respectively.  Banana stored 5.7 t C ha^-1 while nut-bearing coconut stored 24.1 ha^-1.  Of the four agricultural crops examined, coconut was the most stable for C storage, as it is a perennial.  Imperata cylindrica (cogon) and Saccharum spontaneum (talahib) were the dominant species in the grassland ecosystem.  S. spontaneum and I. cylindrica stored 13.1 and 8,5 t C  ha^-1, of which 87% and 60%, respectively, were stored in the shoot system.  Due to the common practice of burning crop residues (wetland rice and sugarcane) and controlled burning of grasslands (cogon and talahib), these species were likely to lose a significant portion of their C.

Carbon Dioxide Sequestration Potential of a Secondary Forest Ecosystem in Mt. Makiling Forest Reserve

Tropical forests are important sources and sinks of carbon (C).  However, there is limited information on the ability of tropical forests to store and sequester C.  The study aimed to quantify the C stocks of a secondary forest formation in mt. Makiling Forest Reserve, Philippines. The results showed that total biomass (above and below-ground) of the forest was 576 Mg/ha with an annual tree biomass accumulation of 12 Mg/ha/yr.  At an average of 43% C content of biomass, the total C stocks was 418 Mg C/ha including soil organic (SOC) which comprised about 40% of the total.  C sequestration rates were estimated 5 Mg C/ha/yr.  Some important implications of the results were discussed.

Philippine Forestry and CO2 Sequestration:  Opportunities for Mitigating Climate Change

Lasco, R.D. and F.B. Pulhin.  1998.  Environmental Forestry Programme, UPLB-CFNR, College, Laguna. 24 pp.

Global warming, or climate change in general, and its consequences are among the most pressing issues today.  These changes have been attributed to the rise in concentration of greenhouse gasses (GHG) in the earth's atmosphere.  GHGs like CO2, CH4, NO2, and chlorofluorocarbons absorb thermal radiation emitted by the earth's surface.  Thus, rising concentration of GHGs in the atmosphere could lead to a change in energy balance and consequently the world's climate.  Forest ecosystems play an important mitigating role in climate change because they can both be sources and sinks of CO2 (Trexler and Haugen, 1995).   The Philippines is one of the tropical countries that have a high potential for forestry options to mitagate climate change, specifically carbon emissions.  It has a sizeable forest land area that could be developed for carbon sequestration projects.  This handbook is a first attempt to provide guidelines on how carbon sequestration through forestry practices could be implemented in a tropical country like the Philippines.