RICE TERRACES MACRO-INVERTEBRATES AS INDICATOR OF WATER QUALITY IN INDIGENOUS COMMUNITIES OF THE CORDILLERA REGION NORTH LUZON, PHILIPPINES

Abstract

The Cordillera region is the cradle of rice terraces in the Philippines Island of Southeast Asia as shown by the famous Banaue Rice Terraces. Diverse organisms including macro-invertebrates need these unique habitats to survive and complete their life cycles, and water quality contribute to this diversity. Two study sites were established based on accessibility. Sampling plots were based on altitudinal gradients. The taxon composition and richness of macro-invertebrates, index of similarity and pollution status of these sites were determined. Samples were handpicked and collected using the indigenous method. Collected samples were identified using standard books and monographs and taxonomic keys provided by Myer et al. The sampes were grouped to taxa based on the Environmental Protection Agency adopting the Ireland EPA biotic system for macro-invertebrates. There were 15 macro-invertebrates species belonging to 14 genera under 9 taxa. The sites show similarity index of 61.5 percent indicating more taxa at the most accessible sites probably due to human introduction. The biotic index of the sites indicated a moderately polluted status. This implies the indigenous practice of recycling back organic litters back to the rice fields. These indigenous practices could have maintained the food web and at the same time preservig the biological diversity in the rice terraces of the Cordillera Region.