University of Sri Jayewardenepura: Journals & Proceedings
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Exploring the Importance of Vernonia zeylanica: An Endemic Medicinal Plant for Conservation, through Phytochemical Analysis
No full textVernonia zeylanica known as “Kupillay” in Tamil, “Pupula/Heen botiya” in Sinhala, an endemic species of Sri Lanka is an important medicinal plant. Its leaves are used specially for skin disease in Indigenous medicine. Similarly, the stems are recommended to be used in the treatment of boils and fractures of bones. This plant has a dense distribution in the dry-wet zone of Sri Lanka. It is a shrub which grows about 1 to 2.5 m tall. Young stems are densely pubescent. It has small leaves with petioles. Flowers are found as 6 to 8 in per capitulum. Recent data reports that the scientific name of Vernonia zeylanica has been changed to Jeffreycia zeylanica and it was mentioned in the National red list of Sri Lanka (2020), as least concerned. Its anti-inflammatory, anti-proliferative, anti-bacterial and anti-nociceptive activities have been reported previously. There is a strong possibility that this endemic plant of Sri Lanka could possess a lot of useful phytochemicals which are responsible for its pharmacological action. But this has not been scientifically tested yet. The aim of this study was to identify the phytochemicals in the leaves of the Vernonia zeylanica and to find out the phytochemicals present in the leaves and to compare them with the pharmacological action mentioned in past research papers. The leaves of Vernonia zeylanica were collected from the Kaithady in the Northern Province of Sri Lanka in August 2024 as it a medicinal plant, the leaves are crushed in mortar and pestle without adding water, as mentioned in the traditional method of Indigenous medicine, then sent to the Department of Chemistry, Faculty of Science, University of Jaffna for phytochemical analysis. Vernonia zeylanica leaf extract was tested for phytochemicals like alkaloids, flavonoids, phenolic compounds, tannin, glycoside, saponins, terpenoids, reducing sugar, protein and steroids using different test methods for qualitative analysis. The test result revealed that the leaf extract contains phytochemicals like alkaloids, flavonoids, phenolic compounds, tannin, saponins, terpenoids and reducing sugar. The results revealed that the presence of many beneficial phytochemicals justifies its therapeutic action. Such endemic plants may face significant threats such as habitat loss, climate change and invasive species. Conserving endemic plants helps to maintain biodiversity and ecosystem stability. Efforts typically include establishing protected areas, habitat restoration and raising awareness about their importance. Such an important endemic plant should be conserved for future use.
Keywords: Endemic, Medicinal plant, Vernonia zeylanica, Phytochemical analysi
Culturable Endophytic Microbial Community Structure in Healthy and Die-Back Infected Callophyllum walkeri in Horton Plains, Sri Lanka
No full textThe cause of forest dieback in the upper montane forest at Horton Plains (HP) remains unexplained despite several past investigations. Shifts in the structural profile of endophytic microbes due to conditions experienced by plants could cause beneficial or detrimental effects on plant health. This study aimed to compare the structural composition of the endophytic microbiome between healthy and die-back affected Callophylum walkeri trees at different stages of die-back progression using culture dependent approaches to elucidate the role of endophytic microbes in the dieback process. Sampling was done from two 0.4 ha plots in the forest which represented healthy trees (H) and die-back infected C. walkeri trees at four stages of die-back progression, namely, S1 (foliage discolouration), S2 (defoliated), S3 (stem defects) and S4 (bark damage). Leaves and core samples of roots and stems were collected in triplicate per plot from H, S1, S2, S3 and S4 trees. Endophytic fungi, bacteria and actinomycetes were isolated from all samples using specific culture media. Endophytic actinomycetes were not observed even after one month’s incubation. Relative abundance (RA) and percentage isolation frequency (PIF) were computed for endophytic fungal and bacterial morphospecies. Gram positive bacteria were present in all plant parts of healthy and die-back infected stages. Fungal RA and PIF differed significantly among plant parts (p<0.05) with roots and leaves showing the highest and lowest RA and PIF respectively. However, there was no significant variation in fungal RA or PIF between healthy and die-back affected trees. Truncatella sp., Neopestalotiopsis., Pestalotiopsis sp., collectively termed as Pestalotiods, were present as endophytic fungi in roots and stems of both healthy and die-back affected C. walkeri at all stages. Similarly, they were present in leaves at S1 stage. Relative abundance of bacteria differed significantly (p<0.05) among plant parts and stages of die-back development, where leaves and stem samples reported the highest and the lowest values respectively. The highest bacterial RA was observed at S3 stage whereas the lowest was at H, S1 and S4 stages which did not differ significantly among themselves. The PIF of bacteria was not significantly different among plant parts or stages of die-back. This study revealed that RA of the endophytic fungal community did not differ between healthy and die-back affected C. walkeri trees. Even though RA of the endophytic bacterial community showed variation with stage of die-back development, the observed pattern of variation did not reveal a clear role in the die-back process.
Keywords: Endemic, Morphospecies, Progression of Die-back, Pestalotiods  
Preliminary Study of Sea Urchins Associated to Two Locations in Southern Coast of Sri Lanka
No full textSea urchins (Echinodermata) are an essential class of herbivores in both temperate and tropical food webs. They maintain the amount of macroalgal cover, affecting primary productivity and phase changes on reefs. The sea urchin has been recognized as a cultivable marine invertebrate species because of its commercial potential. This study aims to determine sea urchin diversity and abundance at two locations covering the Pareiwella and Polhena coral reefs in southern Sri Lanka. The study was carried out using permanent transect sampling method and transects were parallel to shoreline with the length varying from 10m-20m at the selected sites during low tide at 0.5m-1m depth range in Pareiwella and 0-0.5m depth range in Polhena to estimate the sea urchin abundance during December 2023 to January 2024. In the field, a 0.5 m × 0.5 m quadrate was placed along transects at permanent points, and each species of sea urchin was counted within the quadrate. The abundance and diversity of Sea urchins at two sites were estimated, and their mean values were compared. According to the results, a total of 4-6 sea urchin species (Diadema setosum, Stomopneustes variolaris, Toxopneustes pileolus, Tripneustes gratilla, Echinothrix calamaris and Echinometra mathaei from Polhena and Diadema setosum, Stomopneustes variolaris, Tripneustes gratilla, and Echinometra mathaei from Pareiwella) were identified between the two sampling sites. On the Pareiwella and Polhena site, sea urchin distribution is recorded as 33 individuals m-2 and 12 individuals m-2 respectively. Shannon Weiner index of diversity was highest in Polhena (H’=1.1). Results showed the dominance of Stomopneustes variolaris in Polhena reef and Echinometra mathaei in Pareiwella reef. Stomopneustes variolaris and Echinometra mathaei resulted in higher abundances for distribution in the Pareiwella and Polhena site respectively. Further studies are necessary to investigate the feeding preference of sea urchins in a wider context.
Keywords: Sea Urchins, Diversity, Abundance, Distribution 
Evaluating the Efficacy and Safety of Clove Essential Oil as a Sedative for Long-Term Transportation of Xiphophorus helleri
Get PDFSedative agents are effective additives to be used during long-term live-fish transportation, mainly in the ornamental fish sector to relieve stress and ensure fish welfare. The current study, which included two phases, investigated the effectiveness and safety of clove (Syzygium aromaticum) essential oil (CEO) during the long-term transportation (24 h) of Xiphophorus helleri (Swordtail). Phase I of the experiment was conducted to evaluate the efficacy and safety of CEO added to the transportation water at four concentrations (0, 5, 10, and 15 mg/L). During this phase of the experiment, a long-term transportation scenario of 24 h in sealed plastic bags was simulated under laboratory conditions. Then, sampling was carried out immediately before transportation, immediately after transportation, and 96 h post-transportation to find out differences in water quality parameters (temperature, pH, ammonia concentration (AMC), and dissolved oxygen concentration (DO)), blood glucose level (BGL) in fish, and survival percentage of fish between the treatments. Our results showed that the water quality was reduced after 24 h of transportation simulation as indicated by significantly lower DO, pH, and significantly higher AMC measured at 24 h compared to the measurements taken just before transportation. Moreover, transportation caused stress in the fish as perceived by the elevated BGL in fish at the end of the transportation. Interestingly, the use of 10 mg/L CEO offered the most favourable results as indicated by significantly higher DO and significantly lower AMC and BGL in this treatment compared to 0 mg/L CEO treatment immediately after transportation. However, there was no significant difference in the mean survival percentages of the treatments. Phase II of the experiment tested the effect of ethanol, used as the solvent for CEO in Phase I. The 10 mg/L CEO concentration, identified as the most effective and safe in Phase I, was compared with a treatment containing only 96% ethanol, the solvent used for CEO. According to phase II findings, there is no interference in the use of ethanol as a solvent for CEO in Phase I. In conclusion, clove oil shows promise for use in the long-term transportation of live X. helleri due to its sedative properties, which help reduce water quality deterioration and stress levels in fish.
Keywords: Ornamental fish, Syzygium aromaticum oil, Blood glucose level, Water quality, Additives 
Use of Non-Biological Methods for Agarwood Production in Aquilaria and Gyrinops Species
Get PDFAgarwood, a highly valued resin from Aquilaria and Gyrinops species of Family Thymalaeaceae, is formed as a defense response to prevent the internal tissue damage caused by stresses. The natural formation of agarwood resin takes a long time and therefore, to meet increasing demand, non-biological methods for agarwood production have been developed, including mechanical, chemical, and physical inducement techniques. Those methods can be categorized into conventional and non-conventional methods. Mechanical methods, such as drilling, girdling, and bark removal create physical injuries that trigger resin production. While cost-effective and simple, these methods often yield inconsistent resin quality and may harm tree health, reducing long-term productivity. Advanced drilling techniques combined with the application of microbe-attractants, such as sugar syrups can enhance resin yield but still face limitations in commercial scale. However, chemical induction methods provide more controlled and efficient resin formation. Techniques like chemical injection and saltwater application mimic natural stressors, inducing oxidative stress and resin synthesis. Chemicals such as sulfuric acid, jasmonic acid, and ethylene have been successfully used, while innovative approaches, named Whole-tree Agarwood-Inducing Technique (Agar-WIT) ensure uniform resin distribution. These methods require technical expertise and pose risks of chemical toxicity to the tree and environment. Physical inducement method; thermal stress utilizes abiotic factors to stimulate stress. These approaches are gaining attraction due to their precision and minimal environmental impact. Thermal stress employs heat to disrupt cellular integrity. Some other physical methods such as aeration and whole-tree agarwood inducing technique are also effective. The aeration method involves inserting an aeration device, made from materials such as plastic, bamboo, or wood, with a diameter of approximately 2 cm, into a wound on the tree. This device prevents the pores from healing, thereby facilitating a long-term infection essential for agarwood formation. The whole-tree agarwood inducing technique employs simple and cost-effective transfusion sets to inject agarwood inducers directly into the xylem section of the tree. This method significantly enhances agarwood production, yielding 4 to 28 times more high-quality agarwood compared to traditional approaches. The comparative analysis of these methods reveals distinct advantages and challenges. Mechanical methods are accessible but less reliable, chemical methods are efficient but require careful handling, and physical methods balance precision with sustainability but need higher costs and expertise. Integrating these approaches with modern innovations offers potential for optimizing agarwood production to meet global demand while preserving ecological balance.
Keywords: Chemical, Mechanical, Physical, Inducers, Resin formatio
Assess the Impact of Lionfish (Pterois volitans and Pterois miles) as an Invasive Species in the Marine Shallow Waters of Hikkaduwa, Colombo, and Trincomalee in Sri Lanka
No full textMarine invasions pose a significant threat to the Ocean’s biodiversity. The lionfish species Pterois volitans and Pterois miles are among the marine invaders. Despite the global attention on lionfish, no previous studies have been conducted focusing on the presence of lionfish and their impacts on Sri Lankan waters. This is the first study in Sri Lanka focused on assessing the current status of lionfish distribution (P. volitans and P. miles), abundance, and invasiveness in Hikkaduwa, Colombo and Trincomalee areas aiming to evaluate their impact on biodiversity. This study was carried out from June to August in 2024. It consisted of a pilot social survey in Hikkaduwa, Colombo and Trincomalee. Based on its findings, a field survey was subsequently carried out in five selected locations in marine shallow waters of Trincomalee using an underwater visual sensing method. Additionally, a qualitative study was conducted through key informant interviews. The social study results revealed a significantly higher presence of lionfish in Trincomalee than in Hikkaduwa (X2 (1,112)=7.816, P<0.05) where there were no significant differences in the presence of lionfish between Colombo and Hikkaduwa (X2 (1,72)=0.856, P<0.05) and Colombo and Trincomalee (X2 (1,102)=2.342, P<0.05). It further measured the public awareness of lionfish distribution and their impacts. The field survey results were calculated based on 25m long line transects (5m wide on both sides) for 2-3 minutes durations across all five locations, treating as uniform sampling areas. The results showed the presence of lionfish was very low in the locations with high biodiversity (SHDI=1.973±0.273). The areas with low biodiversity (SHDI=1.071±0.680) had high relative dominance (RD=49.02%) of lionfish (P. volitans and P. miles). The key informant interviews highlighted the possibility of a lionfish invasion in Sri Lanka. They emphasized the need for further exploration and investigation to gain an accurate and precise understanding of the status of lionfish distribution in Sri Lanka. The study discovered significant insights into the public awareness and distribution of lionfish. It further revealed the ecological, economic and medical impacts of lionfish. Moreover, it highlighted the need for further exploration, including temporal variations to reach more precise and accurate conclusions regarding their long-term ecological impact to determine their invasive behaviour in Sri Lankan waters.
Keywords: Lionfish, P. volitans, P. miles, Invasive species, Native invader
Forest Restoration Efforts in Sri Lanka: Successes and Failure
No full textThe restoration of forests has become a vital priority in Sri Lanka, due to significant loss of forest cover in recent years, which has caused significant harm to its ecosystems and biodiversity. The objective of this study is to assess the effectiveness of forest restoration projects in Sri Lanka. The restoration project data was obtained from the Department of Forest Conservation, Sri Lanka. It contained information on forest restoration projects and Assisted Natural Regeneration (ANR) maintenance from 1987 to 2015. A logistic regression model is used to measure the success probability of projects. The model was trained with data derived from major successful restoration projects, ANR and the global forest restoration data. The model's parameters were the total project area, project duration, human population density in restoration area and locality. Success probability 0.6 was selected as the threshold value. It was consistently applied to classify projects as successful or unsuccessful. The model AUC value was 0.756. ArcGIS Pro was used to monitor forest cover. Data were sourced from Global Forest Watch (GFW), Global Land Analysis and Discovery (GLAD), and satellite images. Results of the regression model revealed that, mean success probability of the restoration projects was 0.613. Success probability in the wet zone was 0.71 and the successful probability in the dry zone was 0.55. Smaller restoration areas tend to be with higher project success and projects in wetter locations have higher project success. Forest cover monitoring results discovered that Sri Lanka lost 10.7 kha of humid primary forest between 2002 and 2022. This represented a 1.8% decrease in the total area of humid primary forest. Sri Lanka lost 210 kha of tree cover between 2001 and 2022, which represents a 5.3% decrease in tree cover since 2000. Between 2001 and 2022, 23% of tree cover was lost because of deforestation. Seven districts were responsible for 54% of all tree cover loss between 2001 and 2022. Anuradhapura had the most tree cover loss at 32.3 kha compared to an average of 8.40 kha. From 2000 to 2020, the country experienced a net change of -175 kha (-3.8%) in tree cover. This highlights the urgent need for sustained and comprehensive restoration efforts. It is a priority to address the underlying drivers of deforestation and enhance the success rates of restoration projects.
Keywords: Forest restoration, Assisted natural regeneratio
Analysis of Urban Growth and Land Use Changes in Selected Divisional Secretariats (DSD) in Anuradhapura District, Sri Lanka, Using Geographic Information Systems (GIS) and Remote Sensing (RS)
No full textThe process of urban growth and its associated land use changes have a significant impact on sustainable development and resource management. Changes in land cover led to deforestation and because of that human-wildlife conflict escalated in the Anuradhapura district, Sri Lanka. Therefore, this research aims to analyze the urban growth patterns in 18 Divisional Secretaries (DSD) (i.e., Padawiya, Kebithigollewa, Medawachchiya, Nuwaragampalatha, Rambewa, Kahatagasdigiliya, Horowpathana, Galenbindunuwewa, Mihintale, Anuradhapura, Rajangane, Talawa, Tirappane, Palugasewewa, Kekirawa, Ipalogama, Galnawa and Nuwaragam Palata) in Anuradhapura district between 2010 to 2024 using Geographical Information Systems (GIS) and Remote sensing (RS). After obtaining United States Geological Survey (USGS) images covering the study area for the years 2010 and 2024, supervised classification based on the maximum likelihood classifier was applied to the imagery to prepare Land use/Land cover (LULC) maps with four land cover classes: forests, water bodies, croplands, and built-up areas. Land extents for each LULC type were calculated, and the changes in the area between 2010 and 2024 were compared using ArcGIS 10.8. The supervised classification indicates that forest cover and the cropland areas decreased (1,876.38 km2 to 1,006.25 km2 and 1,553.62 km2 to 850.80 km2, respectively) while water bodies and built-up areas increased (333.92 km2 to 1,127.38 km2 and 1,713.80 km2 to 2,494.99 km2, respectively). The overall accuracy for the 2010 and 2024 (LULC maps) are 0.84 (84%) and 0.81 (81%) respectively, highlighting the reliability of the results. The decrease in forest cover may be contributing to the increased human-wildlife conflict in the Anuradhapura district and the decrease in cropland areas shows the pressures that have been exerted by expanding built-up zones. The increase in water bodies most probably indicates the construction of reservoirs to support urban expansion. So, overall, these findings indicate the severe changes in land use patterns throughout the study period, escalated largely by urbanization and its impacts on the natural environment. This study emphasizes the need for efficient urban planning and resource management strategies in the Anuradhapura district to balance developmental requirements with environmental sustainability. By applying remote sensing and GIS technology, this research provides a valuable tool for policymakers to monitor and manage land use changes and ensure the long-term sustainability of the area’s natural resources.
Keywords: Land use classification, Maximum likelihood supervised classification, GIS, Deforestation, Sri Lank
Growth Rate Effects on Wood Density and Ring Characteristics of Over-mature Pinus caribaea in Sri Lankan Plantations
No full textThe current oversupply of mature and over-mature Pinus caribaea (Pine) plantations in Sri Lanka necessitates optimal resource utilization, particularly for private furniture manufacturing and export industries. This study investigated the relationship between growth rate and wood quality parameters by examining radial relative density and ring width variations within and between trees, focusing on slow, medium, and fast-grown trees, with particular emphasis on over-mature specimens. Wood quality assessment employed the maximum moisture content method to determine relative density, with measurements standardized at 12% moisture content to facilitate comparative analysis. The experimental design incorporated Boron treatment on selected samples to evaluate its impact on wood quality parameters. Data analysis utilized descriptive statistics and one-way ANOVA with Tukey's post-hoc comparisons using Minitab 16 software. Results revealed that fast-grown trees exhibited significantly higher relative density than slow and medium-grown counterparts, while no significant differences were observed between slow and medium growth rates. This suggests that Pinewood relative density may be largely independent of growth rate within the slow to medium growth range. Ring width analysis demonstrated a consistent pattern across all growth rates, characterized by an initial decrease in juvenile wood and stabilization in mature wood, attributed to cambial ageing or canopy closure. Relative density variations from pith to bark displayed distinct patterns according to growth rates: slow-grown trees exhibited an initial decline followed by a slight increase towards the bark; medium-grown trees maintained a relatively constant density after an initial decline, and fast-grown trees showed an initial decrease followed by irregular slight increases. The transition from juvenile to mature wood formation occurred consistently at approximately ten years, independent of growth rate. The findings suggest that implementing silvicultural practices promoting faster growth rates could yield high-quality mature Pine wood without compromising wood properties. Moreover, Boron treatment showed no statistically significant effect on wood quality, indicating its potential as a preservative treatment option to enhance durability and rot resistance while maintaining wood properties. These results are important for optimizing Pine plantation management and wood utilization strategies in Sri Lanka.
Keywords: Pinus caribaea, Relative density, Ring width, Growth rate, Wood qualit
Altitudinal Segregation of Non-Volant Mammals along a One-Kilometer Elevation Gradient in the Highlands of Sri Lanka
Get PDFAltitudinal segregation is an ecological phenomenon where different species are distributed only in distinct elevation bands in mountainous regions. Here, we examined the altitudinal segregation of non-volant mammals, terrestrial species incapable of sustained flight, along a one-kilometer elevation gradient in a sub-montane region of Sri Lanka to categorize them by elevation, habitat, and temporal factors. Wildlife census techniques such as camera trapping, scat and pellet sampling, small mammal trapping, and opportunistic observations, were conducted from the Samanalawewa Basin (480 m above mean sea level) to Hawagala Peak (1,420 m AMSL) in the Issengard Biosphere Reserve, Belihuloya, from November 2022 to April 2024, recording 20 mammal species, including five endemics and seven threatened species. All species, except the Feral Water Buffalo (FWB) (Bubalus bubalis), were recorded in the mid-elevation range (650-1,100 m AMSL). Four species, Barking Deer (BD) (Muntiacus muntjak), Wild Boar (WB) (Sus scrofa), Mouse sp., and Golden Palm Civet (GPC) (Paradoxurus zeylonensis) span all elevation ranges (480-1,420 m AMSL). The Dusky-striped Squirrel (DSS) (Funambulus obscurus) is restricted to mid-elevations, while the FWB is confined to high elevation range. Most species peaked at mid-elevation, indicating the mid-domain effect. Cluster analysis identified two primary clusters. The first, consisting of 13 predominantly nocturnal species, includes a subcluster of nine species from lower elevations with higher temperatures, divided into mid-elevation forest species and a singleton cluster for WB, found across all elevations. The forest subcluster is split into two groups: one with higher elevation species, including GPC, Indian Pangolin (Manis crassicaudata), and another with lower elevation species, including Asian Palm Civet (Paradoxurus hermaphroditus), Crested Porcupine (Hystrix indica), Yellow-striped Chevrotain (Moschiola kathygre), and Indian Small Civet (Viverricula indica). A separate subcluster includes higher elevation species, with the FWB as a singleton due to its restriction to high elevations. Leopard (Panthera pardus), Black-naped Hare (Lepus nigricollis), and Sambar (Rusa unicolor) are clustered together, with the latter two further grouped by their grassland habitat preference. The second cluster comprises seven diurnal species, including a singleton for the high-elevation Purple-faced Langur (Semnopithecus vetulus). The remaining species from lower elevations are split into two subclusters: one with relatively higher elevation species, such as BD, DSS, and Stripe-necked Mongoose (Herpestes vitticollis), and another with lower elevation species, including Indian Palm Squirrel (Funambulus palmarum), Giant Squirrel (Ratufa macroura), and Toque Macaque (Macaca sinica). Principal Component Analysis supports these clustering patterns, showing that temperature, habitat, and elevation drive mammal segregation in this transect. Understanding these distribution patterns can be useful for conservation planning since some altitudinally segregated species are endemic and threatened.
Keywords: Altitudinal segregation, Non-volant mammals, Mid-domain effect, Cluster analysis, Issengard Biosphere Reserv