Undergraduate Special Problem
Permanent URI for this collectionhttps://hdl.handle.net/20.500.14583/30
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Item Mangrove community structure survey in Iloilo RiverBayate, Bryna Kimberly L. (Division of Biological Sciences, College of Arts and Sciences, University of the Philippines Visayas, 2004-04)Mangroves are highly productive forests growing along tropical tidal mudflats and shallow water coastal areas where water is generally brackish. The structure of the mangrove stand in the Iloilo River was studied using the transect line plot method with 55 plots established in the 3 out of 4 stations of the river. Community Structure is described in terms of the following parameters: basal area, stems per hectare, relative density, relative frequency, relative dominance and importance value of the species and the Shannon Index of Diversity. Variations in these parameters are correlated with certain physico-chemical factors- soil and water temperature, soil and water pH, and water salinity.Nineteen(19) true mangrove species were found in the area belonging to 10 families. These include Mysinaceae family represented by Aegiceras corniculatum ; Avicenniaceae family represented by Avicennia alba, Avicennia marina, Avicennia officinalis and Avicennia rumphiana; Euphorbiaceae family represented by Excoecaria agallocha; Sterculiaceae family represented by Heritiera littoralis; Combretaceae family represented by Lumnitzera racemosa; Palmae family represented by Nypa fruticans; Rhizophoraceae family represented by Bruguiera cylindrica Rhizophora apiculata, Rhizophora mucronata, and Rhizophora stylosa; Sonneratiaceae family represented by Sonneratia alba, Sonneratia caseolaris, and Sonneratia ovata.Ruciaceae family represented by Scyphiphora hydrophyllacea and Meliaceae family represented by Xylocarpus granatum, and Xylocarpus meckongensis. Avicennia officinalis has the highest total basal area of 650.69m2/ha, Avicennia alba, Aegiceras corniculatum, Avicennia marina, Avicennia officinalis, Avicennia rumphiana, Exoecaria agallocha, Lumnitzera racemosa, Rhizophora apiculata, Rhizophora mucronata, Rhizophora stylosa, Sonneratia alba and Xylocarpus moluccensis have equal relative frequency of 0.074. Avicennia marina obtained the highest stems per hectare with a value of 38933.33, relative density of 0.405 relative dominance of 0.332 and importance value of 0.913. The index of diversity is 1.010, indicating that the area is diverse.Item Zooplankton composition, abundance and diversity in selected Municipalities of Negros Occidental and AklanAusan, Aisa Marie U. (Division of Biological Sciences, College of Arts and Sciences, University of the Philippines Visayas, 2015-06)Zooplankton samples were collected last May and June 2014 from 20 stations in the vicinity of Kalibo, Aklan and Pontevedra, San Enrique, and Valladolid, Negros Occidental. Three hundred fifty-three (353) liters of water were filtered per station thru a 5m vertical haul of plankton net with a diameter of 30cm and a mesh size of 20μm. Overall zooplankton densities were higher in Negros Occidental, specifically in Valladolid (D=1915.3 cells/L), than in Kalibo, Aklan (D=7.2 cells/L). On the other hand, zooplankton community was most diverse in Kalibo (H’ = 2.6) compared to Valladolid (H’=1.3), San Enrique (H’=2.1) and Pontevedra (H’=1.8). Jaccard’s similarity index was highest between Pontevedra and San Enrique while lowest between Valladolid and Kalibo. In Kalibo there were four major groups of zooplankton. Most dense of these were the tintinnids (3.9 cells/L) followed by copepods (2.5 cells/L), molluscs (7xlOE-lcells/L) and polychaetes (IxlOE-lcell/L). Among the copepods Subeucalanus was the most abundant zooplankton genus. In Pontevedra and San Enrique, Negros Occidental, copepods were the most abundant group with a mean density of 205.3 cells/L and 312.1 cells/L, respectively. The relative abundance ofAcartia (36.5%) and Longipedia (22.6%) made them the dominant zooplankton genera in Pontevedra and San Enrique, respectively. Like in Kalibo, the tintinnids were also the most abundant group in Valladolid (1879.2 cells/L). Copepods followed with a mean density of 35.7 cells/L, while Polychaetes comprised only 4xlOE-l cells/L. Epiplocylis was the most abundant tintinnid in Valladolid while Xystonella in Kalibo. Varying sampling time within months and day is the possible cause of the differences in zooplankton abundance, composition, and diversity since some zooplankton species undergo diel vertical migration.
