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Trees are found in various formations, ranging from individual trees to randomly occurring tree clusters and systematically established tree plantations, as well as natural forests. Accurate information about trees, their distribution and density is crucial for the development of national policies, strategies, and management decisions related to tree planting, and environmental management. While some organizations and individuals have mapped forests, home gardens, and trees outside forests at different scales, the lack of comprehensive and systematic spatial distribution data on trees and tree cover density in Sri Lanka has been a significant challenge for policymakers. To address this issue, this study utilized the tree cover mapping (TCM) tool developed by U.S. Geological Survey. High-resolution images were visually interpreted within a geographic information system interface to map tree cover. The TCM tool employed a systematic sample grid, with a sampling interval of 200 m. The study encompassed 1.64 million sampling units, and mapping and interpretation were conducted at a scale of 1:3000. The resulting tree density map had a resolution of 200 m. Results show that 78% of the country's land area has a tree cover density exceeding 10%, resembling open and sparse forests, while 64% of the country exhibits a tree cover density exceeding 40%, comparable to dense forest areas. The study found that although forest cover was limited in districts such as Colombo, Gampaha, and Jaffna, these areas still displayed a significant level of tree cover density, offering services and functions similar to those provided by forests. [ABSTRACT FROM AUTHOR]

Among numerous studies done with homegardens (HGs), few efforts have been drawn up to examine biodiversity, input availability and the influence of the complex environment of households and HGs on its produce. Interventions to improve HGs are generally done within the administrative boundaries of the region and the success of such attempts should be evaluated using appropriate tools. To address this research gap a study was formulated aiming at grouping selected HGs and identifying the variables contributing to grouping; and thereby suggesting the characteristics of a model HG. A HG survey was conducted focusing Ratnapura and Hambantota districts of Sri Lanka. Pooled and separated samples of HGs in the two districts were employed in K-means cluster analysis and the groups obtained were subjected to discriminant function analysis to derive the important variables in discriminating HGs. The HGs in Ratnapura were grouped into three categories and key variables contributing to differentiate those were annual expenditure for HG, labor usage, above ground biomass, disease occurrence, species density of trees, and tree density. There were four groups of HGs in Hambantota and key variables that contributed to their differences were; annual expenditure for HG, pest occurrence, annual income from HG, species density of trees, the total share of produce in HG used for consumption, technical knowledge on farming and land extent. Accordingly, the income-driven and diversityenhanced components of a HG would make it a model HG achieving maximum productivity. However, due to the heterogeneity of HGs, distinct groups within a district could not be identified, suggesting the inappropriateness of making administrative boundaries-based decisions on the interventions in HGs. [ABSTRACT FROM AUTHOR]

Homegardens (HGs) serve as crucial 'Trees Outside Forest Sources' (TOFS) systems, offsetting tree cover loss resulting from extensive deforestation in the Upper Mahaweli Catchment (UMC) over the past two centuries. This study examined the temporal and spatial distribution of HGs in relation to agroecological regions (AERs) within the UMC boundary, assessed the tree density of HGs, and analyzed the biophysical and socioeconomic factors influencing tree density. Geospatial assessment utilized Landsat Images and tree density estimation was based on a random sample of 500 HGs in the UMC with a minimum diameter at breast height (dbh) of >10cm. Regression analysis was employed to identify factors affecting tree density. The spatial assessment revealed that in 2017, the AER of IM3a covered the highest percentage area (66.5%) whereas IM1a recorded the greatest incremental percentage change (22.8%) from 1992-2017, while the lowest change was observed in IL2 (0.03%). The highest tree density was observed in IU2 (858 trees/ha), and the average density in WM2a (505 trees/ha), comparable to that of South-Asian tropical rainforests. However, there is a concerning trend of rapid spread of exotic species contributing to the high tree density observed in IU2, WM2a, and IU3d. The multiple linear regression model (p<0.01, R2 = 58.62%) indicated spatial, agronomic and institutional factors positively influenced tree density. Conversely, the HG area square, and demographic factors had a significant negative impact on tree diversity (p<0.01). To ensure the ecological sustainability of the UMC, the study proposes to introduce an appropriate incentive package to enhance tree density in HGs, with native species. [ABSTRACT FROM AUTHOR]

Homegardens are resourceful ecosystems that provide essential services to the environment and mankind. Their contribution to secure household food requirement is among the provisional services of contemporary relevance. A study was conducted in 429 homegardens in Jaffna, Matale, Ratnapura, and Hambantota districts to assess the scope of utilizing homegarden resources on household food security. A questionnaire survey was conducted to gather information on the consumption frequency and the number of food categories that were purchased, produced, and shared. The mean food consumption score (FCS) was 60±23, where 89% of the study population had an acceptable level of FCS (FCS>35). As per the dietary diversity score (HDDS), an average household consumed at least eight food categories per day. Coconut was the most common food commodity produced in homegardens, followed by jackfruit and other fruits (mango, guava, soursop and pomegranate). Households rely on the market-available foods as their primary food source. The study revealed that utilizing at least one food category as a homestead-resource produced, could improve FCS and assist to fulfil the household food demand significantly. However, the majority of the homestead-resources were identified as plant-based, except in Jaffna where the presence of livestock and poultry in homegarden was common. Many of the plant-based resources were from perennial fruitbearing trees. Therefore, modifying and utilizing the tree composition and viable crops can be considered a timely option to avert household food insecurity. Further, incorporating livestock components (dairy, poultry) as a part of homegardens is beneficial in fulfilling the animal protein demand of the household. [ABSTRACT FROM AUTHOR]

The demand for Ceylon cinnamon (Cinnamomum verum syn. C. zeylanicum) is consistent due to its superior characteristics. Besides that, Sri Lanka is home to seven other wild species: Cinnamomum capparu-coronde, Cinnamomum citriodorum, Cinnamomum dubium, Cinnamomum litseifolium, Cinnamomum ovalifolium, Cinnamomum rivulorum, and Cinnamomum sinharajaense. Since cinnamon bark contains more than seventy bioactive compounds, it possesses various pharmacological and health benefits, including antimicrobial activity. Even though there is some literature on the antimicrobial activity and chemical composition of C. verum, wild species have not been studied yet. The present study evaluated the antimicrobial activity and biochemical compounds of Cinnamomum species found in Sri Lanka using bark methanol extract and crude. Trans-cinnamaldehyde, cinnamyl alcohol, cinnamyl acetate, coumaric acid, and coumarin were quantified using HPLC techniques. The antimicrobial properties were evaluated by disc diffusion assay against two standard pathogenic strains, Escherichia coli ATCC 25922 and Pseudomonas aeruginosa ATCC 27853. There were no detectable coumarin or coumaric acid levels in any of the species. The highest transcinnamaldehyde content and antimicrobial activity were observed in C. verum, followed by C. sinharajaense and C. capparu-coronde. Further, C. ovalifolium, C. dubium, and C. rivulorum did not show positive inhibition zones against the two pathogenic strains and detectable levels of transcinnamaldehyde. Moreover, the results showed a strong positive correlation between antimicrobial activity and transcinnamaldehyde content. The results suggest that the antibacterial activity of C. sinharajaense and C. capparucoronde should be tested against a broader range of pathogenic strains and could be useful in future breeding programs. [ABSTRACT FROM AUTHOR]

Lasia spinosa (L.) Thwaites (LS) is characterized by its pointed and sharp spines which is an impediment to popular commercial cultivation. Apart from typical LS, there are morphotypes: lamina dissected (LD), mixed (MX), and spineless (SP). The aim of the study was to investigate the potential of a spineless type as a crop for use in addition to spiny LS types. Plant growth and yield parameters were evaluated using field-grown plants of each type and in the assessment of nutritional and organoleptic properties. There were no differences among growth rates of MX, SP, and LS leaves. Both leaf and rhizome yield were not different among LS and its morphotypes. The SP had similar N, P, and K concentrations in the rhizome and tender leaves compared with other morphotypes and LS. The LS and its three morphotypes having less phenols had less antioxidant capacity. Crude fiber content was not different between samples. Even though spineless type was not different in yield and growth and nutritional and organoleptic properties, it has high potential to be used in future improvement of L. spinosa as an edible aroid. [ABSTRACT FROM AUTHOR]

Agarwood produced by Gyrinops walla Gaertner, an endemic plant species of Sri Lanka, arguably the costliest wood, is used as a major constituent in cosmetic industries. Application of plant cell culture technique serves as the best alternative for the production of fragrance compounds of G. walla while ensuring the sustainability of the species. Using the advantages of plant cell culture and Thin Layer Chromatography (TLC), a preliminary study was carried out to compare the phytochemical constituents of callus and plant extracts (i.e stem, leaves, bark and agarwood) of G. walla. Different callus lines were developed on MS and modified MS media with reduced level of NH4NO3, supplemented with different combinations and concentrations of plant growth regulators and multiplied. Freeze dried samples were extracted with hexane, ethyl acetate and methanol and run on a TLC plate under different eluting solvent systems. A higher number of TLC spots were observed in the ethyl acetate extracts of all samples, under 15 percent methanol: chloroform solvent system. Based on TLC chemical profiles of all callus lines, MS media added with 1.0 mg/L BAP, 0.5 mg/L kinetin and 0.1 mg/L 2,4-D and 1/2 MS contained 1.0 mg/L BAP and 0.1 mg/L 2,4-D were selected as best lines. The extracts of the selected two callus lines matched with the fingerprint profiles of best plant samples i.e stem, bark and agarwood. Compounds present in the extracts of callus samples, plant samples and agarwood, appearing at Rf=0.56, 0.74 and 0.78, could be used as possible markers for G. walla. The chromatography profiling by TLC has proven the presence of similar phytochemical constituents in callus, plant samples and agarwood. Therefore, it can be concluded that plant cell culture technique guarantees the possibility to produce same compounds that are present in plant and agarwood of G. walla. [ABSTRACT FROM AUTHOR]

Leaf spot and rough bark diseases are of high concern among cinnamon growers in Sri Lanka due to potential yield losses. Comprehensive information on distribution and intensity of the above diseases is not available in Sri Lanka. During this study, disease assessment keys were developed for leaf spot and rough bark diseases with subjective scales, which could be useful in assessing the severity of the two diseases. Two hundred and eighty cinnamon accessions from major cinnamon growing areas of Matara, Galle, Kalutara, Kurunegala, Ratnapura and Humbantota Districts were used to determine the intensities of the above diseases. All the districts showed a high level of leaf spot disease severity, where 23.81% accessions from Galle and 17.14% accessions from Kalutara districts exhibited the leaf spot disease severity scale of 6. Moreover, 60% accessions from Kurunegala and 45.71% accessions from Kalutara districts showed the leaf spot disease severity scale of 5. According to the study on rough bark disease severity, none of the major cinnamon growing areas is at a high risk of rough bark disease. However, the present study indicates the initiation and progression of rough bark disease in the six districts, where Matara district showed considerable levels of infection having 17.39%, 11.59%, 5.80% and 4.35% of accessions with disease severity scales 2, 3, 4 and 5, respectively. The estimates of the two disease severities explain the present scenario of extent of the two diseases across major cinnamon growing areas in the country. [ABSTRACT FROM AUTHOR]

The cinnamon flowers exhibit protogynous dichogamy with 2 flower types "Type A" and "Type B" which first flowers during morning and evening respectively. This floral cycle causes a temporal barrier to the maintenance of elite breeding material and for hybridization with desired parents. Determination of variation in flower and inflorescence morphology can shed light on functional diversity in "Type A" and "Type B' flowers. In order to study these variations, a survey of cultivated cinnamon lands and wild habitats was conducted in fifteen locations in the Matara district. Peduncle length (PDL), flower length (FL), flower width (FW), and floral tube length (FTL) varied among cinnamon accessions collected. The variation in tepal shape was distinct: the two whorls of tepals of a single flower exhibited two shapes. The current investigation of differences in inflorescence, floral morphology and floral abnormalities of Cinnamomum verum provides information about their diversity, and recommends molecular analysis to further determine the genetic basis of two flower types in progynous dichogamy. [ABSTRACT FROM AUTHOR]

Tamarindus indica L. (tamarind) is a tropical tree species widely managed for fruit and other exported products in countries like India and Thailand. In Africa tamarind was earmarked for livelihood diversification however, conservation strategies, products/markets were not yet developed moreover, unsustainable utilisation and habitat losses has led to its populations and expectedly genetic resources erosion. Additionally, because tamarind population structure was not yet well defined even globally, knowledge on genetic structure requisite to classify the extent and nature of genetic erosion and thus conservation needs/strategies for its populations was lacking. The objective of our study was to generate knowledge on tamarind populations genetic structure which we hypothesised was influenced by habitats, latitudes and isolation by distance. We studied polymerase chain reaction-restriction fragment lengths polymorphisms (PCR-RFLP) in the slow evolving, organelle genomes of 311 tamarind sampled on-farm, woodland and riverbanks in island-mainland, higher-lower latitudes of nine geographic regions. Analysis revealed significant among geographic regions mitochondria genetic structure (ΦST = 0.64) but only one of its 6 haplotypes was global (overall frequency, 59.6%), one restricted to Kenya, Tanzania, Mexico (overall frequency, 12.8%) and the rest endemic to Kenya (2), Indonesia (1) and Thailand (1). The chloroplast was conserved (ΦST ≤ 0.02), only one of its 16 haplotypes was global (overall frequency of 94%), 14 were rare endemics of East Africa and one restricted to Kenya-Indonesia (overall frequency<1%). Cytotypes genetic structure was significant (ΦST = 0.49) but with 51% variability within geographic populations and only one of the identified 20 was global (overall frequency, 51.89%), one was restricted to Burkinafaso, Indonesia, another one to Kenya, Tanzania, Mexico while the rest were endemic to East Africa and one in Thailand. Clearly, geographic population specific conservation strategies are needed for tamarind and the East African populations are worthy conservation priority as centre of diversity. [ABSTRACT FROM AUTHOR]