Nathaniel C. Bantayan

Linking objective and subjective modelling for landuse decision-making

Abstract This paper describes a landuse modelling approach developed for the Makiling Forest Reserve in the Philippines. The process includes application of the analytical hierarchy process (AHP) but extends this approach to include objective process based modelling – in the form of the universal soil loss equation (USLE) – in the subjectively oriented framework of AHP. A geographic information system was used for data assembly and to define decision zones and a PC based interface developed to accommodate interactive application of the AHP and USLE models. Having successfully combined the objective and subjective elements for evaluation of landuse alternatives, the paper explores the options for landuse allocation based on the suitability assessments of a participating decision group.

Near infrared spectroscopy: a rapid and non-destructive technique to assess the ripeness of oil palm ( Elaeis guineensis Jacq.) fresh fruit

Near infrared (NIR) spectroscopy as a rapid and non-destructive technique was used with principal component analysis and linear discriminant analysis to develop an alternative technique for oil palm fresh fruit ripeness classification. The fruit samples were broadly classified into four main ripeness grades: unripe, under-ripe, ripe and over-ripe. A total of 3870 samples of individual fruits were taken at different stages of ripeness between 6 and 27 weeks after anthesis. Right after field collection, fresh samples were sent immediately to the laboratory for NIR and wet chemistry analysis. Two parameters, oil and moisture content in mesocarp were used as prior reference to determine the ripeness grades of oil palm fresh fruit. The NIR spectra of the ripe and over-ripe grades had higher absorbance compared to the unripe and under-ripe grades. The overall average accuracy of the classification by ripeness grades using this technique for both the training and the validation set samples was larger than 81%. In practical application, the rapid and non-destructive NIR technique has potential use for classifying oil palm fresh fruit into ripeness grades.

Diameter at breast height estimation in Mt. Makiling, Laguna, Philippines using metrics derived from airborne LiDAR data and Worldview-2 bands

Airborne LiDAR is fast becoming an innovation for forest inventory. It aids in obtaining forest characteristics in areas or cases where actual field inventory would be very tedious. This study aims to estimate diameter at breast height (DBH) using airborne LiDAR point-cloud parameters with Worldview-2 satellite images, and to validate these with actual measurements done in the field. The study site is a field plot with forest inventory at Mt. Makiling, Laguna, Philippines that was surveyed into 20m, 10m and 5m subplots or grids. The estimation of DBH was carried out by extracting the said parameters from the LiDAR point-cloud, and extracting different bands from the Worldview image and performing linear and log-linear regression of these values. The regressions were done in four different cases, namely: LiDAR parameters without intensity (case1), LiDAR parameters without intensity with Worldview bands (case 2), intensity of LiDAR points (case 3), and LiDAR parameters with intensity and Worldview bands (case 4). From these it was found that the best case for estimating DBH is with the use of LiDAR parameters with intensity and Worldview bands in a 10x10 grid, in Log-Linear regression with a root mean squared error of 1.96 cm and an adjusted R2 value of 0.65. This was further improved through stepwise regression, and adjusted R2 value was 0.71.

Landscape Pattern Impacts on the Population Density and Distribution of Black Shama (Copsychus cebuensis Steere) in Argao Watershed Reserve, Argao, Cebu, Philippines

This study determined the impacts of landscape pattern on population density of C. cebuensis within AWR, a conservation priority in Cebu, Philippines. Three land uses were identified, namely, (a) cultivated (3,399 ha/45%); (b) forestlands (3,002 ha/40%); and (c) build-up (1,050 ha/15%). Forest patches at class have irregular/complex shapes; thus the forest areas in AWR are more fragmented and heterogeneous. Estimated population density of C. cebuensis was 52 and 53 individuals per hectare in mixed and natural forests. There were only three predictors at the landscape and four at the sampling site level, respectively have able to explain the behavior of the population density of C. cebuensis. Relative humidity and canopy cover were having high positive significant correlations while tree basal area has high negative correlation (at landscape). Elevation and canopy cover have positive high significant and significant correlations, while slope and shrub cover have negative significant correlation with C. cebuensis population density. The adjusted values were 0.345 and 0.212 (at landscape and sampling site). These suggest that about 34.5% of the variations of the population density of C. cebuensis have been accounted for by the former and only 21.2% by the latter. Preservation and protection of remaining forest fragments within AWR are paramount.