A VEGETATION STUDY IN TWO SELECTED SITES OF MEETHIRIGALA FOREST RESERVE

Meethirigala Forest Reserve, which is a patch of tropical evergreen rain forest, situated in theGampaha District, bordering the Kegalle District, was studied, to characterise the forest withrespect to vegetation structure. Floristic composition, stratification, species richness, speciesdiversity and basal area of the vegetation were studied during a period of eight monthscommencing from February 2000. Data were collected from a site (A) presumed to be a lessdisturbed and relatively disturbed (B). Site A is situated within the area belongs to a monasteryand hence is of restricted accessibility. Two plots each from the two sites, of the size, 30m*30mwere sampled.Species richness was higher (42 species) in site B than in A (14). Diversity of species in site Awas 2.08 and in site B it was 3.35. These figures showed a significant difference at 1%confidence level according to t-test. Species richness determined by Margalefs index shows asignificant difference between the plots with site A, 2.0 and site B having 6.1. The evenness insite A (2.08) was lower than in site B (3.35). Endemism was higher in site A with 21.4%endemic species and in site B it was 11.9%. The distribution of individuals in stem diameter(dbh) classes was similar in both the sites with a reversed "J" shaped curve, indicating this forestcommunity being composed mostly of smaller plants. However in site B there were noindividuals representing largest class taken into consideration (i.e. 70-80 em) and it contains themost number of individuals in dbh class 3 (i.e. 20-30 ern) whereas in site A dbh class 2 has themost number of individuals. Basal area figures in site A is greater with a III.24m2 of total basalarea and a stand basal area orO.94m2 In site B the values are 81.71m2 and 0.74 respectively.However both the sites showed a reversed "J" curve with regard to basal area distribution,among individuals. Considering the height class distribution, class I (i.e. <5m) showed aconsiderable increase in the number of individuals in site A than in site B. In site A, especially inplot I the understorey was of relatively low density and the stratification was disturbed. Theaverage slope calculated was 0.38 m per meter in site A. It was 0.46m per meter in site BDistribution of dbh in the community shows reversed "J" curve, a trend similar to that ofSinharaja rain forest community. This is true for both the sites in Meethirigala. In site A thenumber of individuals in the largest height class considered is similar to that of the Pasoh ForestReserve in Malaysia. Pioneer species like Macaranga peltata and Schumercheria castaneaefoliaare found in site B. Endemism figures are significantly lower in Meethirigala than in Sinharaja.Results of the present study suggest that, the natural structure of both the forest sites have beenaltered by human activity. Selective logging, destroying the forest for other non-timber productsand encroachment of forestland have caused disturbance to the forest vegetation in site B. Site Aappears more disturbed. This may be due to the fact that the two plots selected in sight A arelocated near the steam and they are more easily accessed by the villagers. It appears that bothsites are disturbed more or less to a similar extent.

Possible link of Chronic arsenic toxicity with Chronic Kidney Disease of unknown etiology in Sri Lanka

In recent years a significant increase in number of patients of Chronic Kidney Disease of unknown etiology (CKDu) has been observed in some parts of Sri Lanka, especially in the North Central Province. A case control study has been performed with the intention of determining the prevalence of clinical features of Chronic Arsenic Toxicity (CAT) among CKDu patients in Padavi Sripura divisional secretarial area in Trincomalee District, Sri Lanka. Clinical assessment were done in diagnosed CKDu patients (n=125) and non-CKDu persons (n=180) as the control group. Hair and urine samples collected from both CKDu patients and controls were analyzed for presence of arsenic using Atomic Absorption Spectrometry equipped with Hydride generator (HG-AAS).The results revealed that 68% of CKDu patients and 28% of the controls had urine arsenic levels above 21 µg/g creatinine, which is considered the point of threshold for manifestation of early renal changes that can be developed in to chronic kidney disease. Among the CKDu patients, 48% and 17.4% of the subjects in the control group have fulfilled the criteria to be diagnosed CAT, indicating the potential link between CAT and CKDu. Agrochemicals could be the possible source for this contamination of arsenic since no reported work is available to indicate the presence of arsenic in the bedrocks of Sri Lanka.   Key words: Chronic kidney disease, arsenic, agrochemicals, Sri Lank

Taxonomy of the order Mononegavirales: update 2016

In 2016, the order Mononegavirales was emended through the addition of two new families (Mymonaviridae and Sunviridae), the elevation of the paramyxoviral subfamily Pneumovirinae to family status (Pneumoviridae), the addition of five free-floating genera (Anphevirus, Arlivirus, Chengtivirus, Crustavirus, and Wastrivirus), and several other changes at the genus and species levels. This article presents the updated taxonomy of the order Mononegavirales as now accepted by the International Committee on Taxonomy of Viruses (ICTV)

Environmental assessment for wetland management in Sri Lanka

SIGLEAvailable from British Library Document Supply Centre- DSC:DX181360 / BLDSC - British Library Document Supply CentreGBUnited Kingdo

Spatial Distribution of Water Quality Parameters in Malala Lagoon of Bundala National Park, Sri Lanka

Malala Lagoon of Bundala national park is one of the major wetland ecosystems on the southern coast that supports migratory and residential avifauna. However, the physicochemical characteristics of this lagoon have largely been influenced recently due to upstream irrigation works, especially, Lunugamvehera irrigation scheme, the drainage water of which is partly released into. The presence of invasive plants in these wetlands/lagoons is commonly attributed to the ecological changes that possibly have resulted from altered water salinity caused by increased freshwater input into these wetlands This study was conducted to investigate the current status and spatial variation of water quality in the Malala lagoon. Water samples were randomly collectedfrom fifteen locations from three strata, i.e.Malala North (MN), Middle (MM), and South (MS). Water samples collected for 2 years, representing wet and dry seasons were analysed for nitratenitrogen (NO3-N), ammonium nitrogen (NH4-N), total nitrogen (TN), orthophosphate (PO4-P) total phosphate (TP), pH, salinity and electrical conductivity (EC). These parameters were interpolatedusing ArcMap 10.2.2 software to determine the spatial distribution patterns. Results revealed that concentrations of NO3-N, NH4-N, TN, PO4-P, TP forms, and EC, pH, the water level of the entire lagoon were ranged as 303.0-510.8 µg L -1 , 202.7 -452.8 µg L-1 , 500.1-2200.1 µg L -1 , 4.1-27.4 µg L - 1 , 11.1-52.3 µg L -1 , 598.0-1973.0 μS cm-1 , 7.05-8.14 and 63.0-217.0 m respectively. The highest concentration of all species of nitrogen and phosphorous were observed from the northern part of Malala lagoon (MN), this is the area that receives the drained irrigation water or agricultural runoff. These higher concentrations gradually decrease towards the Sothern part of the lagoon which is closer to the outlet. Lower EC and salinity in the Northern section of the lagoon is also due to the dilution with the excessive freshwater that enters the lagoon. The present study provides an insight into the spatial variation of the quality of water that manifests the anthropogenic impact on lagoon ecology.Keywords: Wetland ecology, Water quality, Malala Lagoon, Impact of agricultural drainag

Taxonomy of the order Mononegavirales: Second update 2018

In October 2018, the order Mononegavirales was amended by the establishment of three new families and three new genera, abolishment of two genera, and creation of 28 novel species. This article presents the updated taxonomy of the order Mononegavirales as now accepted by the International Committee on Taxonomy of Viruses (ICTV)

Taxonomy of the order Mononegavirales: update 2019

In February 2019, following the annual taxon ratification vote, the order Mononegavirales was amended by the addition of four new subfamilies and 12 new genera and the creation of 28 novel species. This article presents the updated taxonomy of the order Mononegavirales as now accepted by the International Committee on Taxonomy of Viruses (ICTV)