Volume 22 Nos. 1 & 2

Aboveground biomass and carbon stock assessment of forest plantations in Mindanao


The study was conducted to estimate biomass accumulation of five forest tree plantation species (bagras, falcata, mahogany, mangium and yemane) and quantify the carbon stock of the commercial plantations in Mindanao.

The plantations surveyed had a wide range of stand ages (1-25 years old) and planting density of 191-10,000 trees/ha. Allometric equations developed by ERDB in 2009 based on diameter at breast height and total height were used to predict the tree aboveground biomass and total carbon stock of the plantations.

Based on 273 plots established inside the plantations, the biomass density of the five species ranged from 1 to 1,109 tons ha-1 and carbon density ranged from 1 to 523 tons C ha-1 at different sites.

The mean biomass of the five species is 183.1 tons ha-1 for an average stand of 12 years old. As a whole, the plantations (2,002 ha) contained a total aboveground biomass of 268,228 tons which has sequestered an equivalent of 126,181.9 tons CO2 from the atmosphere.

Region 12, having the highest number of planted forests (1,146 ha), gave the highest total biomass of 111,108.6 tons. This was followed by Region 13 (71,174.4 tons) and Region 11 (34,546.9 tons), respectively.

The total carbon stock of the plantations surveyed was 126,181.9 tons C which is equivalent to 463,084 tons CO2 sequestered from the atmosphere. Among the five forest tree species evaluated, mangium stored and sequestered the biggest amount of carbon. With a total of 328.3 ha of plantations, mangium was able to store 53,930 t C. This represents 42.8% of the total amount of carbon stored by the plantations in Mindanao.



An assessment of Light Detection and Ranging (LiDAR) for base mapping in Kalimantan, Indonesia


This research investigated the handling and processing of LiDAR data from Kalimantan, Indonesia. It involved filtering to derive bare earth and classifying vegetation, buildings, towers, and other object points. Different parameters were tested to find the optimum settings in the successful generation of digital terrain models (DTM) over urban and forested areas. Assessment of the quality of the LiDAR data in terms of overlapping points between strips was also conducted. The orthophotos produced from the images taken simultaneously with LiDAR showed that seamless orthophoto can be achieved by using LiDAR as ground control points (GCPs). The feasibility of 3D building modelling with the data was evaluated. It is presented by comparing the LiDAR-generated building models with the stereo-compiled roof boundaries. Overall, results of the study proved that LiDAR could augment and speed up the mapping process for production of topographic data.



Analysis of issues and trends in timber and timber products trade flow situation in the Philippines


The study analyzed the flow of timber and timber products among industry players, including the demand and supply, and identified the issues and bottlenecks in the trade flow and possible solutions to these problems.

A nationwide survey among different industry players such as the timber producers, processors, and end-users (i.e., households, construction firms) was conducted to acquire a better picture of the timber and timber trade flow situation in the country. Analysis showed that the weak trading situation and problems in the timber products flow are primarily caused by the limited access and sharing of information among industry players. There are also certain policies and regulatory issues that further aggravate the situation.

Perception of the industry players illustrates that there is a definite downward trend in the demand for lumber and supply of raw materials, yet majority of these players still foresee that the quality of local raw materials will remain the same or improve. Despite the negative views, it is apparent that majority of the industry players are still hopeful on the future of investing in plantation development.



Effects of background variations on vegetation indices for mangrove forest in Taklong Island, Guimaras Province


This study investigated the effects of various background conditions typically found in mangrove communities on the relationships on various spectral vegetation indices and leaf area index. ASTER image was used to identify/classify mangrove areas within the study area. Mangrove canopy spectral reflectance and leaf area index (LAI) were measured in the field using a spectrometer and Photo synthetically Active Radiation (PAR) sensor. These data were then used to calculate Spectral Vegetation Indices such as NDVI, SAVI2, and OSAVI. The relationships between several spectral vegetation indices measured from the field and derived from ASTER image and field LAI have been assessed particularly the effects of background variation typically found beneath mangrove canopies. As expected, soil influences are prevailing in partially vegetated canopies, they are more significant in LAI below 1.5. Based on the correlation coefficient, the vegetation indices which consider soil parameter normalized the soil-background effects such as SAVI2, OSAVI, with corresponding regression coefficient of 0.81, 0.74, respectively. Based on the result of 3D plot of SMA over various types of vegetation indices, SAVI2 turned out to be sensitive to background or substrate variations in almost all types of substrates.



Stakeholders' perceptions on the Community-Based Forest Management Projects implementation in selected areas of Leyte Province, Philippines


The study aimed to evaluate the extent of implementation and level of people’s participation in four selected sites of Community-Based Forest Management (CBFM) projects in the province of Leyte, Philippines. Findings will serve as basis for proposed interventions toward the improvement of program implementation.

The extent of implementation of the CBFM projects in terms of the rules and regulations under the Implementation Stage was perceived by the primary stakeholders or project beneficiaries as substantially implemented in the projects managed by CUFA-MPC, FSMIRAI and Mag-aso CBRMPSA, whereas fully implemented by PIAFDAI. Significant differences were established in the perception of the primary stakeholders in the extent of implementation of the rules and regulations among project sites. The perception of PIAFDAI project beneficiaries is significantly higher compared to CUFA-MPC, FSMIRAI and Mag-aso CBRMPSA. The secondary stakeholders, i.e., DENR implementers, LGUs and other assisting organizations perceived the extent of implementation of the rules and regulations in the CBFM projects managed by PIAFDAI, CUFA-MPC and FSMIRAI as substantially implemented whereas in the Mag-aso CBRMPSA it is perceived as partially implemented.

The project beneficiaries perceived their level of participation in key CBFM activities as moderate by PIAFDAI and CUFA-MPC and low participation by the FSMIRAI and Mag-aso CBRMPSA beneficiaries. Highly significant differences were established on the primary stakeholders’ perception on their level of participation in activities, namely, application of silvicultural practices such as thinning, weeding, and assisted natural regeneration, plantation establishment, maintenance and protection in established plantations, livelihood activities, and forest product utilization.

Participation or involvement of the four POs in CBFM key activities is not significantly related with age, gender, civil status, educational attainment, monthly income, household size and religion except for the gender of FSMIRAI members which is highly significant.

The study drew some recommendations to improve the CBFM implementation which included the need for a strong coordination among CBFM primary (project beneficiaries) and secondary (DENR implementers, LGUs and other assisting organizations) stakeholders in all CBFM activities, the requirement for teamwork and concerted efforts of these stakeholders to ensure effective implementation and strengthen project beneficiaries’ participation, and creation of an effective and always functional participatory monitoring and evaluation team composed of representatives from the DENR, POs, LGUs and other assisting organizations.