Plant Community Diversity, Productivity and Succession in Lahar Areas of Bacolor, Pampanga

Abstract

Three lahar affected barangays in Bacolor, Pampanga were studied for vegetation analysis. The study site was described through its plant composition and its climate. Diversity was measured through quadrat method by random establishment of three 100m transect lines in every site. Harvest method was done to measure productivity. Succession was measured through comparison of data gathered last 2000 by Pascasio and Hailar to those of the researches. The lahar areas represent a typical grassland community composed of 64 plant species belonging to 18 families. A relatively high level of diversity and dominance were observed in the area, in comparison to a previous study. Species from Poaceae and Fabaceae dominated the area. An increase in species richness, diversity and dominance was observed upon comparison to the data obtained in 2000. Short grass and twiners dominate the area in 2000. A huge increase in the number of species and families were also noted. Both studies showed Saccharum spontaneum to be the dominant species in the area. Lahar soil was also seen productive based on its biomass production. Lahar soil changed its physical and chemical properties in comparison to the study made in 2000, giving way for lahar to support plant growth. The plant community is undergoing succession which is evident in the increase of species heterogeneity and improvement of the lahar soil properties compared to previous data. The community is undergoing successive changes and is capable of supporting other species until it reaches stability, favoring a climax community. Among the three sites, Site C is found to be on its late successional stage. It has the most productive soil and the most evenly distributed community, giving way for the dominant species to exploit the resources in the area and define the community structure.