Vegetation analysis of forest over limestone and conservation status of Tectona philippinensis Benth & Hook.f. in two selected sites in Batangas

• Main Authors: Andres, Anna Lyn B., Cordon, Apollo B., Flores, Rowena L., Matias, Michael S.
• Format: text
• Language: English
• Published: Animo Repository 1997
• Subjects: Vegetation classification; Forest site quality; Trees > Identification; Forest conservation; Limestone; Forest ecology; Soils > Analysis
• Online Access: https://animorepository.dlsu.edu.ph/etd_bachelors/8612
• Institution: De La Salle University

A study of forest over limestone was conducted in Brgy. Malabrigo, Lobo and in Brgy. Hugom, San Juan, Batangas to describe the species composition, diversity, and other characteristics of this vegetation type. The study was conducted from the months of September to November. The vegetation analysis was extended to about 4,000 square meter of forest over limestone area using the Belt transect method for each of the study sites. Species of trees with 10 DBH (diameter at breast height) and above were considered. Two hundred two trees comprising 16 species under at least 14 families were found occurring in the Malabrigo study site. In Hugom, 215 trees were recorded which constitute 32 tree species under at least 22 families. Tectona philippinensis Benth. & Hook.f and Terminalia polyantha Pres1 were noted to be dominant in this type of habitat based on their relative frequency, relative density, and dominance values. Species area curve was employed in both sites to show the number of additional species encountered per subplot. The diversity of the two study sites was computed using the Shannon-Wiener Diversity Index. It was found out that species diversity in Hugom (SDI=2.803) is greater than Malabrigo (SDI = 1.643). t-test revealed that there is a significant difference between the diversities of Hugom and Malabrigo (f = 10.21, at 397 df, & 0.05 a). Species evenness was also higher in Hugom (E = 0.809) than in Malabrigo (E = 0.586). Based on the IUCN Red List Category series Tectona philippinensis Benth. & Hook.f. is considered to be a threatened species and categorized as vulnerable. Data about on soil and atmospheric conditions during the time of data collection were also reported. Average soil temperature recorded from Malabrigo and Hugom were 27.3 centigrade and 25.3 centigrade respectively. Soil moisture gave an average of 18.9% and 13.9% for Malabrigo and Hugom respectively. The soil organic matter in the two sites were 19.4% in Malabrigo and 22.9% in Hugom. The pH of the soil was neutral to slightly basic. The soil texture of the two sites was determined to be sandy. The presence of nitrogen and phosphorus was not observed in the soil of both study sites, however, adequate amount of calcium was present in the soil of Malabrigo and Hugom. The average air temperature obtained were 30.4 centigrade and 25.8 centigrade for Malabrigo and Hugom respectively. Humidity in Malabrigo was 74% while in Hugom was 79.7%.