Volume 27 Nos. 1 and 2


 Spectral response of 4 vegetation types during 2009-2010 occurrence of moderate El Niño Southern Oscillation in Cagayan River Basin

An unusual warming of sea surface temperature (SST) along the equatorial Pacific was established in June 2009 to June 2010 which developed weak to moderate El Niño Southern Oscillation (ENSO). Time series vegetation indices of 4 vegetative covers derived from Moderate Resolution Imaging Spectroradiometer (MODIS) sensors were used to understand the effects of El Niño in Cagayan River Basin. The research process used in this study can serve as a guide for vegetation assessment and monitoring, particularly during an El Niño event, for timely crop assessment and monitoring.

In general, the spectral mean test for 4 vegetation categories, namely, forest, agricultural crops, grassland, and woody plants showed that during ENSO years, vegetation index was lower, as shown by a lower mean Enhanced Vegetation Index (EVI) for 3 out of the 4 categories. Only forest areas do not seem to be significantly affected by the El Niño phenomenon. Grassland was the most affected during the ENSO study period. Woody plants such as shrubs and perennial trees were evidently affected by El Niño. Comparison of results based on T-test (at 95% confidence interval) showed that EVI was more accurate in determining the effect of drought on vegetation compared to Normalized Difference Vegetation Index (NDVI). In general, the impact of El Niño to the 4 vegetation categories is more pronounced during summer season since there was adverse dry spell compared to non-summer months.


Aboveground biomass and carbon sequestration of 4 bamboo species in the Philippines

This study on the biomass and carbon sequestration of 4 selected economically important bamboo species in the Philippines, namely, giant bamboo (Dendrocalamus asper Schultes f.), kawayan tinik (Bambusa blumeana J.A and J.H. Schultes), bolo (Gigantochloa levis (Blanco) Merr.), and buho (Schizostachyum lumampao (Blanco) Merr.) was conducted by the Ecosystems Research and Development Bureau (ERDB) from 2013 to 2014.

Aboveground biomass was determined on 243 sample bamboo culms of the 4 species covering a wide range of diameter classes from 9 provinces in Cordillera Autonomous Region (CAR) and regions 1, 2, 3, 6, 7, 10, 11, and 13. The average dry biomass of the 4 species was 51.1 kg for D. asper, 23.6 kg for B. blumeana, 19.1 kg for G. levis, and 3.8 kg for S. lumampao. Prediction equations using allometric models were developed for estimating the ovendry weights of the whole culm using variables such as diameter and total height.

Results on the carbon analysis showed that the aboveground biomass of the 4 bamboo species can store an average of 44.3, 43.6, 43.2, and 39.8 percent carbon for  D. asper, B. blumeana, G. levis, and S. lumampao, respectively. Furthermore, carbon content taken from the samples of the 4 bamboo species revealed that the pole (45.4%) showed significantly higher carbon content in its biomass than the branches (43.5%) and the leaves (39.4%).


A checklist of the orders and families of medicinal plants in the Philippines

A checklist of the orders and families of Philippine medicinal plants is prepared to provide an up-to-date reference for students, teachers, and researchers alike. The accepted names, families, and orders in this checklist follow the recent classification of angiosperms largely based on DNA sequence data by the Angiosperm Phylogeny Group (APG). Available and comprehensive references on Philippine medicinal plants were used to come up with the checklist. These were complemented and updated by online resources retrieved from search engines like Google Scholar and Science Direct. The authors likewise included an alphabetical listing of older and conserved family names. Results indicated a total of 48 orders out of the world total of 64 (75%) and 182 families of the world’s 416 (44%) which were classified according to the APG groupings (Magnoliids, Asterids Commelinids, Fabids, Malvids, Lamiids, and Campanulids) and further organized into subclasses and classes of the presently used Cronquist system (Magnoliidae, Liliidae, Commelinidae, Rosidae, and Asteridae) for convenience and practical use. Moreover, the list recorded 1008 medicinal plant species and the common diseases each species is utilized for. The checklist does not only prove the rich medicinal flora of the Philippines but as well as the extensive knowledge of the local “herbolarios”. Thus, its proper documentation and promotion are imperative to maximize its potential in contributing to the country’s health sector.


Assessment of physical-chemical properties and metal concentrations in leachate from selected open dumpsites in the Philippines (Research Note)

Local dumpsite leachates were studied to understand their basic characteristics. The study aimed to assess the characteristics of leachate in terms of physical-chemical properties, metal concentrations, and other inorganic compounds in leachates collected from open dumpsites. The data generated from the study would provide baseline information on the characteristics of “dumpsite” leachate. Seventy-six sets of representative samples were collected from 38 selected open dumpsites in the Philippines during the 2006 to 2008 sampling activities. Each site consisted 2 leachate samples for physical-chemical, metals analyses and other inorganic compounds. Leachate samples were sourced from waste seeps, flows, or ground slumps located within the study sites. Physical-chemical parameters such as Chemical Oxygen Demand (COD) (15–18,104 mg/L), chloride (7–2,945 mg/L), color (20–5,000 mg/L), alkalinity (4–10,435 mg/L), pH (6.83–9.22), total hardness (30–2,864 mg/L), ammonia (<0.010–5.77mg/L), nitrite as nitrogen (<0.010–59.70 mg/L), orthophosphate, total, reactive (<0.010–9.12 mg/L), total solids (272–12,387 mg/L), total dissolved solids ( 55–10,987 mg/L), and total suspended solids (17–1,870 mg/L) were analyzed. Metal concentrations in leachate such as cadmium (<0.001–0.079 mg/L), copper (<0.005–0.498 mg/L), lead (<0.010–6.84 mg/L), and zinc (<0.002–2.17 mg/L), and other inorganic constituents of leachate such as calcium (1.81–1,080 mg/L), iron (<0.010–3,312 mg/L), magnesium (0.079–275.8 mg/L), potassium (1.22–1500 mg/L), and sodium (0.04–1,676 mg/L) were likewise analyzed. The wide ranges of concentrations suggested that the characteristics of leachate may vary from site to site.


Plant diversity of the Las Piñas-Parañaque Critical Habitat and Ecotourism Area, Luzon Island, Philippines (Research Note)

This study was conducted to highlight the diversity of true, associated, and beach type mangrove and other tree species in the Las Pinas-Paranaque Critical Habitat and Ecotourism Area (LPPCHEA). Information on the distribution and abundance of mangrove and other tree species present in the area is a requisite for its sustainable management.

Sampling of mangrove and other tree species was conducted from September to December 2008. A total of 75 plots were randomly established in Long Island (48 plots) and Freedom Island (27 plots). Transect line plot technique was used to assess the tree species. Tree parameters were analyzed through the use of environmental indicators such as relative density, Shannon Diversity Index, and Shannon Equitability Index.

A total of 8 true and associated mangrove species and 3 beach type species were identified within the critical habitat. These included Avicennia marina (Forsk.) Vierh, Lumnitzera racemosa Wild. 1803, Sonneratia alba J. Smith, Rhizophora spp., Bruguiera sexangula (Lour.) Poiret 1816, Thespesia populnea (L.) Sol. Ex Correa, Morinda citrifolia L., Excoecaria agallocha Linn. 1759, Acacia farnesiana (L.) Willd, Premna odorata Blanco, and Terminalia catappa L. for beach type species.