Оценка воздействия неблагоприятных факторов среды на морских двустворчатых моллюсков с помощью метода днк-комет: автореферат диссертации на соискание ученой степени кандидата биологических наук: специальность 03.02.08 - экология

Sri Lanka’s energy policy presumes that the country will be meeting 20% of its energy requirements by non-conventional renewable energy resources by 2020. This study attempts to assess diesel vehicle owners’ willingness to pay (WTP) for Jatropha biodiesel and the factors affecting their decisions. The Contingent valuation method (CVM) was used to elicit the WTP for the non-marketed biodiesel, which leads to a hypothetical allocation. For diesel vehicle users, a single bid approach was used at Rs.121/= per litre (€ 0.83). The study was carried out in Kandy region among diesel vehicle users. The factors affecting WTP were estimated using probit regression and WTP was estimated using nonparametric estimation techniques. The mean WTP for biodiesel by the diesel vehicle users was Rs.109 per litre (€ 0.74) for lower bound levels. The median WTP was Rs.124/= per litre (€ 0.85). Elderly respondents with higher education are less likely to pay for biodiesel in both samples. Married respondents with higher income are more likely to pay higher prices for biodiesel

Diversity of underutilized vegetables and fruit in Sri Lanka: Prioritization for collection, conservation, genetic improvement, and promotion

Despite their crucial role in combating hunger, malnutrition, and poverty, many plant species cultivated as fruits, vegetables, roots, and tuber crops remain neglected and underutilized worldwide, and Sri Lanka is no exception. Integrating these crops into farming systems has the potential to create nutrient-dense, climate-resilient, and sustainable agricultural practices. The study titled "Diversity of underutilized vegetables and fruit in Sri Lanka: prioritization for collection, conservation, genetic improvement, and promotion" highlights the significance of underutilized vegetables and fruits in Sri Lanka's agricultural biodiversity. These often-overlooked crops possess unique nutritional and agronomic traits that could benefit both farmers and consumers. However, they have been overshadowed by more commonly cultivated species and varieties. To safeguard the genetic diversity and potential contributions of these underutilized crops to food security and nutrition, the study emphasizes the need for prioritizing their collection and conservation. Preserving their genetic resources enables researchers and farmers to access a broader range of traits, enhancing resilience to environmental challenges. Additionally, the research underscores the importance of genetic improvement efforts to boost the productivity and adaptability of underutilized vegetables and fruits. Breeding programs focused on priority species can lead to the development of new cultivars with desirable traits, such as increased yield, disease resistance, and improved nutritional content. Moreover, promoting underutilized crops is essential to raise awareness among consumers, retailers, and policymakers about their nutritional benefits and economic potential. By creating market demand and integrating these crops into agricultural systems, their sustainable cultivation and utilization become more viable. In summary, recognizing and prioritizing the diversity of underutilized vegetables and fruits in Sri Lanka is crucial. Through strategic collection, conservation, genetic improvement, and promotion efforts, these crops can significantly contribute to enhancing food security, preserving biodiversity, and supporting sustainable agricultural practices in the country

Tropical and subtropical Asia's valued tree species under threat

Tree diversity in Asia's tropical and subtropical forests is central to nature-based solutions. Species vulnerability to multiple threats, which affects the provision of ecosystem services, is poorly understood. We conducted a region-wide, spatially explicit vulnerability assessment (including overexploitation, fire, overgrazing, habitat conversion, and climate change) of 63 socio-economically important tree species selected from national priority lists and validated by an expert network representing 20 countries. Overall, 74% of the most important areas for conservation of these trees fall outside of protected areas, with species severely threatened across 47% of their native ranges. The most imminent threats are overexploitation and habitat conversion, with populations being severely threatened in an average of 24% and 16% of their distribution areas. Optimistically, our results predict relatively limited overall climate change impacts, however, some of the study species are likely to lose more than 15% of their habitat by 2050 because of climate change. We pinpoint specific natural forest areas in Malaysia and Indonesia (Borneo) as hotspots for on-site conservation of forest genetic resources, more than 82% of which do not currently fall within designated protected areas. We also identify degraded lands in Indonesia (Sumatra) as priorities for restoration where planting or assisted natural regeneration will help maintain these species into the future, while croplands in Southern India are highlighted as potentially important agroforestry options. Our study highlights the need for regionally coordinated action for effective conservation and restoration

Commercial Orientation and its Effects on Plant Diversity in Homegardens: An Empirical Investigation of Rural Households in Sri Lanka

It could be argued that commercially oriented famers pay more attention on reaping short term commercial benefits from their home-gardens and hence would not focus on longer term benefits that could be derived through enhanced biodiversity. Although empirical studies have been conducted to measure trade-offs between commercial orientation and plant diversity, hardly any research has carried out with the focus on homegardens in Sri Lanka. The main objective of this study is to explore the trade-offs between commercial orientation of farmers and plant diversity in homegardens in three districts in Sri Lanka, viz, Batticaloa Kandy and Kurunegala. The specific objectives are to (i) measure the degree of plant diversity in home gardens, (ii) measure the degree of commercial orientation of farmers, and (iii) to econometrically estimate the relationship between plant diversity and commercial orientation of farmers. Data for this study were collected through a survey carried out in the three districts in 2009. Plant diversity was measured using three indices, namely Richness index, Shannon index and Simpson index and the degree of commercial orientation of farmers was measured using a number of proxies to capture the extent of market transactions and perceptions among farmers towards the purpose of farming. A set of multiple regression models were specified treating the levelof commercialization, land size, employment status, education, household income and the geographical region as independent variables and plant diversity as the dependent variable. The results of the calculated indices revealed that homegardens in Kandy and Kurunegala districts are quitediverse in plants and it is not that diverse in Batticaloa district. Approximately one half of the famers in Kandy and Kurunegala districts and four fifth of the farmers in Batticaloa are commercially oriented. The regression results showed that the farmers with commercial orientation tend to maintain home gardens with relatively higher plant diversity in Kandy district. However, commercial oriented farmers in Kurunegala district tend to maintain homegardens with less plant diversity compare to that of noncommercial oriented. The results also revealed that the plant diversity increases with the increase in land extent and 0.42 ha and 0.53 ha was estimated to be the land area which brings about the maximum plant richness in homegardens in Kandy and Kurunegala districts respectively

Flower morphological diversity of cinnamon (Cinnamomum verum Presl) in Matara District, Sri Lanka

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