Articles



Vol. 25 Nos. 1&2

Climate change has taken a huge impact in the research world. Several studies have been conducted to determine its effects in the environment. In the Philippines, while we have lower carbon emissions compared to other developing countries, we are considered to be one of the most vulnerable to the impacts of climate change.

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Volume 24 Nos. 1 & 2

Biomass and carbon sequestration of Jatropha curcas L. plantation Maximo V. Lanting, Jr. Science Research Specialist Ecosystems Research and Development Bureau College, 4031, Laguna stvincent1945@yahoo.com Leuvina M. Tandug, Ph.D. Assistant Director, ERDB Paulino A. Umali, Jr. Science Research Specialist II Nelson Levi M. Lantican Science Research Assistant One of the most pressing problems nowadays is global warming brought about by the increasing levels of greenhouse gases, particularly carbon dioxide (CO2), in the atmosphere. Plants take up CO2 from the atmosphere and store the carbon in their biomass (roots, stems and foliage) through the process of photosynthesis.

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Volume 23 Nos. 1 & 2

Acidity, conductivity and ionic trends of rainwater in acid deposition monitoring sites in Los Baños, Laguna and Quezon City, Philippines Arcely C. Viernes Science Research Specialist II Research and Development Division, Environmental Management Bureau DENR Compound, Visayas Avenue, Diliman, Quezon City Tel. No.: 632-426-4332 Email address: cely_emb@yahoo.com Maricris T. Laciste Science Research Specialist II This study aimed to establish trends of levels of acidity (pH), conductivity (EC), and concentrations of anions (SO4 2-, NO3-, Cl-) and cations (NH4+, Na+, K+, Ca2+, Mg2+) in rainwater on urban and rural acid deposition monitoring sites in the Philippines. The results of the study will be significant in establishing local acid deposition baseline data to prove or disprove acid deposition occurrence in the Philippines and to provide useful inputs for decision-making aimed at preventing or reducing adverse impacts of acid deposition. The investigation was conducted in Los Baños, Laguna (Los Baños site) and Quezon City (Metro Manila site), categorized as rural and urban sites, respectively, under the Acid Deposition Monitoring Network in East Asia (EANET) protocol. Weekly monitoring, collection, and laboratory analysis of samples were conducted using standard analytical methods and EANET quality assurance and quality control (QA/QC) procedures.Time series analysis of data from 2001 to 2009 for both sites showed a general decreasing annual trend for all parameters. Seasonal trends were observed to be consistent with annual trends. Correlations between the parameters analyzed are outside the scope of this study and should be the focus of further assessment of the state of acid deposition in the Philippines.

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Volume 22 Nos. 1 & 2

Aboveground biomass and carbon stock assessment of forest plantations in Mindanao Leuvina Micosa-Tandug, Ph.D. Chief Science Research Specialist Ecosystems Research and Development Bureau Department of Environment and Natural Resources College, Laguna, 4031 Philippines 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.

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Volume 21 Nos. 1 & 2

Plant diversity profile of the Lobo Watershed in Lobo, Batangas Honorato G. Palis, Ph.D. Supervising Science Research Specialist Coastal Zone and Freshwater Ecosystems Research Division Jose Alan A. Castillo Science Research Specialist I Coastal Zone and Freshwater Ecosystems Research Division Merlyn N. Rivera Former Supervising Science Research Specialist Upland Farms Ecosystem Research Division Ecosystems Research and Development Bureau College 4031, Laguna Plant diversity assessment for Lobo Watershed in Batangas Province was conducted to determine species composition and diversity levels. Quadrat sampling technique was used to evaluate the vegetation. Vegetation parameters collected in the field include species identity, number of individuals, and diameter at breast height of trees. Indices such as Shannon-Wiener Diversity, Equitability and Species Richness were all determined for diversity examination.

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Volume 20 Nos. 1 & 2

Changing patterns of land ownership and their impacts on agricultural productivity and agrarian relations in Lucban and Pagbilao, Quezon Doracie B. Zoleta-Nantes Institute on Church and Social Issues Social Development Complex, Ateneo de Manila University Quezon City This research aimed to document the present characteristics of selected landowners and tenants in agricultural production systems and describe the changing patterns of land ownership and food production activities and their corresponding relations on agricultural production and agrarian relations in Barangay Tinamnan, Lucban and Barangay Binahaan, Pagbilao in Quezon Province. The data indicate that there is a need for more directed interventions that would improve not only the capability of the landless tenants and primary land tillers to improve the economic returns and profitability of their agricultural farming systems, but also those of the small-scale landowners and land reform beneficiary-owner-cultivators. Active interventions from the government and educational institutions (i.e., do more research on how to further increase productivity of the different farming and livelihood systems, provide continued agricultural support services, and construction of infrastructure facilities) are necessary to arrive at effective farming strategies to improve the livelihood production capabilities of tenants, landless agricultural laborers, and small-scale land owners or CARP beneficiary owner-cultivators who are tied up in different agricultural production systems such as coconut-based and rice-based farming systems.

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Volume 19 Nos. 1 & 2

Assessment of community vulnerability to environmental changes in Caliraya Watershed, Laguna, Philippines Aurora A. Sodela-Jose, Ph. D Planning Officer III Ecosystems Research and Development Bureau Virginia R. Cardenas, Ph. D. Vice Chancellor for Community Affairs University fo the Philippines Los Baños College, 4031 Laguna, Philippines Vulnerability assessment of Caliraya Watershed was conducted to assess the degree of impacts of environmental changes in relation to social, economic, and biophysical attributes together with the coping mechanisms of the community to reduce such impacts. A total of 367 randomly selected respondents from five direct-impact study sites were interviewed. The survey revealed that the communities living in the watershed are highly vulnerable to social, economic, and biophysical stressors due to environmental changes such as conversion of land use to agricultural farming and kaingin cultivation, increasing charcoal production, in-migration of landless families, and economic activities of resorts and rest houses, among others.

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Volume 18 Nos. 1 & 2

Determining the carrying capacity of the AFO-CBFM area in Talisay City and Minglanilla, Cebu, Philippines Jose Cleo Cary F. Colis Senior Science Research Specialist Daisy Luisa S. Camello Science Research Analyst Ecosystems Research and Development Service Department of Environment and Natural Resources - Region 7 Banilad, Mandaue City This study determined the carrying capacity of Arthur's Farmers Organization - Community-Based Forest Management (AFO-CBFM) area to ascertain the maximum number of families that can be accommodated in the CBFM area without endangering its ecological sustainability and at the same time, meeting and satisfying the social and economic needs of the CBFM beneficiaries. Using Siovin's formula to determine the sample size of respondents, 246 were randomly selected and interviewed. Interview results were classified into socio-demographic, farming systems, psycho-social perception, and limiting factors influencing farmlot productivity. These were then used as bases in determining the CBFM area's carrying capacity model, as well as, the standard area requirement for each AFO-CBFM beneficiary to be able to live a decent life. Using the modified Boullon's formula, the same results were used in determining the area's Potential Carrying Capacity (PCC) and Real Carrying Capacity (RCG The PCC computed value is 420 families while the RCC computed value is 323 families when areas 50% and above and existing plantation are incorporated. The PCC result shows that in AFO's 1,374-ha CBFM area, ideally only 420 families could be accommodated out of its population of 877 families. However, in the case of AFO-CBFM area, the PCC value can be raised higher since majority of beneficiaries derive much of their respective income from non-farm sources. Similarly, the RCC value can also be increased if necessary mitigating measures can be instituted in areas with limiting factors.

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Volume 17 Nos. 1 & 2

Histopathological changes in microbially infected forest tree seeds by Maria dP. Dayan Hyspathological study of microbially infected forest tree seeds was conducted to determine the effect of different fungi on the cellular structures of artificially and naturally infected seeds The mode of infection of Colletotrichum gloeosporioides, Fusarium moniliforme, and Phoma sp. on artificially inoculated seeds of Pterocarpus indicus Willd (narra), Lasiodiplodia theobromae (Ldt), F. moniliforme, and F. solani on Swietenia macrophylla King (mahogany); and F. solani on Samanea saman (Jacq.) Merr. (raintree) was described. Ramification of the hyphal structures from the seed coat to the subepidermal layer and some parts of the cotyledon of narra and endosperm of mahogany was observed. Hyphal growth of F. solani was concentrated mainly on seed coat and less penetration was observed beyond the epidermal layer of raintree seeds.

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Volume 16 Nos. 1 & 2

Chemical changes in microbially infected forest tree seeds by Maria dP. Dayan and Delia N. Mailum Chemical changes in microbially infected seeds of seven forest tree species, three artificially inoculated and four naturally infected seeds, were studied to determine the effect of microfungi on the food reserves of seeds such as starch, total sugar, and fat.

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