Aquatic Insect Similarity Connecting Natural Wetland Habitat and Ricefield for Ecological Rice Production in Agusan Marsh in Mindanao, Philippines
By: Rowena P. Varela
Key Words: Diversity, Species richness, Natural wetland, Lowland rice field, Species similarity.
Int. J. Agr. Agri. Res. 9(1), 140-147, July 2016.
This study describes the relationship of the natural wetland habitats in Agusan Marsh to nearby rice fields and its implication to ecological rice production. Aquatic insects play multiple roles in the ecosystem such as predators, prey to other animals and decomposers which help in maintaining ecological balance. Results revealed that the diversity of odonates was highest in the sedge-dominated swamp among natural habitats which corresponds to the adjoining ricefields. The pattern of clustering of odonates show 3 groups; the rice-sago and rice-sedges sub-cluster, the rice-bangkal, rice-Terminalia, rice-fern, bangkal, sago and sedges sub-cluster, and the Terminalia forest as the outlier. The diversity of semi-aquatic and aquatic bugs was highest in the Bangkal forest while the lowest was in the fern-dominated swamp. The pattern of clustering shows 2 sub-clusters and the outlier Bangkal forest. On aquatic beetles, highest diversity was in the Terminalia forest. The sub-cluster consists of Terminalia habitat and rice-fern, while the other sub-cluster includes rice-Bangkal and rice-Terminalia. The resulting patterns of similarity in diversity and distribution of species in natural habitats and nearby ricefields indicate that ricefields are important temporary habitats for some aquatic insect species and serve as stepping stones for the movement of the insects.