Botany
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Item Bioconcentraton of metals in edible aquatic plants from a Sri Lankan freshwater wetland(Sri Lanka Association for Fisheries and Aquatic Resources, 2008) Amarasinghe, M.D.; Nirbadha, K.G.S.; Liyanage, J.A.Item Can Avicennia marina produce substitutes for pneumatophores?(Sri Lanka Association for Fisheries and Aquatic Resources, 2005) Ambagahaduwa, I.M.; Amarasinghe, M.D.Item Structure of macrophyte communities in a freshwater wetland and their relative capacity of Nitrogen retention(Sri Lanka Association for Fisheries and Aquatic Resources, 2003) Jayawardhana, W.M.P.; Amarasinghe, M.D.Item Human influence on structure of mangrove vegetation in Negombo estuary(Sri Lanka Association for Fisheries and Aquatic Resources, 1999) Perera, K.A.R.S.; Amarasinghe, M.D.Item Structural complexity of strand vegetation and coastal erosion along the South, South West, and West coasts of Sri Lanka(Sri Lanka Association for the Advancement of Science, 2008) Gunawardena, D.T.; Amarasinghe, M.D.Structural complexity of coastal vegetation at eight different coastlines (Weligama, Unawatuna, Hikkaduwa, Ambalangoda, Induruwa, Kalutara, Moratuwa, and Uswetakeiyawa) was analyzed to determine the effect of structural complexity of coastal vegetation on coastal erosion. Vegetation samples were obtained along the belt transects laid perpendicular to the shoreline at each study site. Biomass, cover, density, basal area, diversity, and species richness of coastal vegetation were analyzed to determine the structural complexity of coastal vegetation. Coastal vegetation structure varied among different coastlines with varying erosion rates. An ordination was performed using principal component analysis to examine the relationship between coastal vegetation structure and erosion rates of different coastlines. Analysis revealed that there is a statistically significant relationship between erosion rate and the structural parameters of the coastal vegetation in the zone close to the shoreline (0-10 m). Which means erosion rates decreased with increasing values of structural parameters (indicating structural complexity) of coastal vegetation in the zone (0-10 m) close to the upper limit of the wave breaking area of the coast.Item Coastal vegetation structure and resistance southern coast of Sri Lanka in the mitigation of tsunami impacts(Sri Lanka Association for the Advancement of Science, 2008) de Silva, K.H.W.L.; Amarasinghe, M.D.The present study is an attempt to investigate the relationship between coastal vegetation structure and its capacity to resist wave energy. Thickness of tsunami sand deposits at Rekawa, Kalametiya and Kirinda were measured and used as indicators of degree of resistance by vegetation against tsunami wave that passed through the mangrove vegetation at the respective localities. Belt transects of 30 -40 m long which were laid perpendicular to the lagoon/estuarine shoreline and parallel to each other and at 30-70 m distance from the shoreline were used to collect data on vegetation structure and each was divided into 10 m ×10 m plots. The locations of each tree, sapling, seedling and stump of trees and also girth and height of trees were measured. Moreover thickness of the sand deposited by tsunami wave was taken by digging 1` × 1` pits on the ground. Thus pits were made in each plot along seaward to landward gradient. The results suggest that mangroves and Pandanus odoratissimus communities of closely spaced trees with widely branching canopies, trees with intermediate diameter and greater forest width provide the greatest resistance against tsunami by reducing inundation distance inundation depth and flow velocity of tsunami waves, which explained that coastal forests lessen damage to property and reduce loss of life. Results further explained that wide crowns with prolific branching of Avicennia marina and P. odoratissimus with stilt/ prop roots and dense foliage exhibit the greatest drag resistance against the tsunami wave.Item Growth and accumulation of NaCl of Avicennia marina seedlings under varying salinity conditions: implications on desalination potential(Sri Lanka Association for the Advancement of Science, 2009) de Silva, K.H.W.L.; Amarasinghe, M.D.Item Mangrove vegetation structure and the abundance of shrimps in Chilaw lagoon, Sri Lanka(Sri Lanka Association for Fisheries and Aquatic Resources, 1999) Jayasundera, J.W.K.K.; Amarasinghe, M.D.; Ranawana, K.B.Item Substrate characteristics and species diversity of marine angiosperms in a micro-tidal basin estuary on the west coast of Sri Lanka(Sri Lanka Association for Fisheries and Aquatic Resources, 2007) de Silva, K.H.W.L.; Amarasinghe, M.D.Item Vegetation structure and potential gross primary productivity of mangroves at Kadolkele in Meegamuwa (Negombo) estuary, Sri Lanka(Sri Lanka Association for Fisheries and Aquatic Resources, 2008) Jayakody, J.M.A.L.; Amarasinghe, M.D.; Pahalawattta Arachchi, V.; de Silva, K.H.W.L.