• Energy Research

This research estimates the carbon stock of the subtropical broad-leaved evergreen scrub forest of Lehtrar, a revenue estate of Kotli Sattian, Rawalpindi, Punjab, Pakistan. A total of six nested co-centric plots of 17.84 m2 each were laid out in the forest, having two sub-plots of 5.64 m2 and 1 m2 each, for shrubs and litter, respectively. Stem density, tree height, diameter at breast height (DBH), total tree biomass, and total carbon stock were calculated. In each plot, parameters like latitude, longitude, aspect, slope, elevation, tree count, etc., were catalogued. The carbon value was calculated in pools such as aboveground biomass (AGB), belowground biomass (BGB), litter, shrubs, etc. The tree height was measured using Abney’s level and the diameter at breast height (DBH) with diameter tape, while factors such as volume, shrub mass, litter mass, total tree biomass, and total carbon stock were calculated by using standard formulas. Results showed Olea ferrugineae to be the most abundant tree species in the study area, followed by Acacia modesta. The total average DBH and height were calculated as 17.03 and 16.79, respectively, with the species Dalbergia sissoo having the greatest DBH value. The mean carbon stock came out to be 47.75 tons/ha, with plot number 3 having the highest value of carbon stock, owing to the greatest stem count. The results of the study were significant and reflected a rich stem density, rich biomass, and an adequate carbon stocking capacity. The scrub forests of the study area, being important carbon sinks, are prone to deforestation and forest degradation activities that need to be controlled by using proper forest management practices to keep their carbon sequestration ability intact, as suggested under various reducing emissions from deforestation and forest degradation (REDD initiatives of UNFCCC.

Climate action was among one of the main targets for the United Nation Sustainable Development Goals (i.e. UN SDG: 13), which is to "take urgent action to combat climate change and its impacts". The United Nations Framework Convention on Climate Change (UNFCCC) is also concurred to improve climate change's mitigation and adaptation strategies along with the SDG's goals. Thermal tolerance has been proposed as one of the possible adaptation strategies for animals affected by anthropogenic effects and excess heat from climate change. However, no scientometrics analysis of thermal tolerance research has been conducted to date. As a result, the goal of this study was to gather information from the literature to determine the current state of thermal tolerance, development trends, and current research. Researchers will be able to better understand the trends and development of the thematic research area of thermal tolerance by using scientometric analysis to generate data on thermal tolerance. For frequency, co-occurrence, co-citation, clustering, and burst analysis, CiteSpace software was used. The scientometric review of thermal tolerance studies from 1970 to 2021 (5243 studies) reveals significant increases in the size of the literature, the frequency of citations, and the hotspots investigated. Susan Lindquist and the Journal of Thermal Biology are the most influential authors and journals, respectively. The most common clusters related to the thematic area of thermal tolerance are oxygen consumption and heat shock protein, with climate change and temperature being one of the most popular keywords. We concluded that, along with the thriving field and climate change issues, thermal tolerance is becoming one of the future research interests. In addition, knowing the current trends and developments of thermal tolerance in aquatic species is important for various stakeholders.

Abstract Background The Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES) has estimated that invasive alien species (IAS) might cause billions of dollars of losses every year across the world. One example is South-East Asia, where IAS have caused an estimated loss of 33.5 billion USD, affecting the environment, human health, and agricultural production. Factors associated with climate change, such as increased carbon dioxide (CO2), heavy precipitation, and elevated temperatures is expected to facilitate biological invasion, leading only to further financial and public health loss. Thus, further study is needed to identify, collate and categorise what evidence exists on the impacts of climate change on fish and shellfish species that contribute to the list of “One Hundred of the World’s Worst Invasive Alien Species” as identified by the International Union for Conservation of Nature’s (IUCN). Such mapping will identify regions more at risk of biological invasion as climate change progresses. Methods We outline a systematic mapping review protocol that follows the Guideline and Standards for Evidence Synthesis in Environmental Management and RepOrting standards for Systematic Evidence Syntheses (ROSES). We describe how peer-reviewed articles will be collected from Web of Science and Scopus, and then analyzed to create knowledge maps on the impact climate change has on invasive species. Finally, we speculate on how our results will aid future management of invasive species in the light of climate change.

Climate change research on major aquatic species assists various stakeholders (e.g. policymakers, farmers, funders) in better managing its aquaculture activities and productivity for future food sustainability. However, there has been little research on the impact of climate change on aquatic production, particularly in terms of scientometric analyses. Thus, using the bibliometric and scientometric analysis methods, this study was carried out to determine what research exists on the impact of climate change on aquatic production groups. We focused on finfish, crustaceans, and molluscs. Data retrieved from Web of Science was mapped with CiteSpace and used to assess the trends and current status of research topics on climate change associated with worldwide aquatic production. We identified ocean acidification as an important research topic for managing the future production of aquatic species. We also provided a comprehensive perspective and delineated the need for: i) more international collaboration for research activity focusing on climate change and aquatic production in order to achieve the United Nations Sustainable Development Goal by 2030; ii) the incorporation of work from molecular biology, economics, and sustainability.

Euglena gracilis is a unique microalga that lacks a cell wall and is able to grow under different trophic culture conditions. In this study, cell growth, biomass production, and changes in the ultrastructure of E. gracilis cells cultivated photoautotrophically, mixotrophically, and under sequential-heterotrophy-photoinduction (SHP) were assessed. Mixotrophy induced the highest cell growth and biomass productivity (6.27 ± 0.59 mg/L/d) in E. gracilis, while the highest content of fatty acids, 2.69 ± 0.04% of dry cell weight (DCW) and amino acids, 38.16 ± 0.08% of DCW was obtained under SHP condition. E. gracilis also accumulated significantly higher saturated fatty acids and lower unsaturated fatty acids when cultivated under SHP condition. Transcriptomic analysis showed that the expression of photosynthetic genes (PsbA, PsbC, F-type ATPase alpha and beta) was lower, carbohydrate and protein synthetic genes (glnA, alg14 and fba) were expressed higher in SHP-culture cells when compared to other groups. Different trophic conditions also induced changes in the cell ultrastructure, where paramylon and starch granules were more abundant in SHP-cultured cells. The findings generated in this study illustrated that aerobic SHP cultivation of E. gracilis possesses great potential in human and animal feed applications.

Increasing evidence have revealed a positive correlation between gut microbiota and shrimp health, in which a healthy shrimp gut consists of a complex and stable microbial community. Given that both abiotic and biotic factors constantly regulate shrimp gut microbiota, any changes affecting the levels of these factors could cause modification to the gut microbiota assemblage. The goal of this study was to explore the effects of salinity levels and pathogenic Vibrio harveyi infection on the diversity, structure, composition, interspecies interaction, and functional pathways of Litopenaeus vannamei gut microbiota. Juvenile shrimp were cultured at 5 ppt, 20 ppt, and 30 ppt for two months prior to Vibrio harveyi infection. After pathogenic V. harveyi challenge test, genomic DNA was isolated from the shrimp gut, and subjected to the 16S rRNA metagenomic sequencing analysis. We observed that gut microbiota diversity of shrimp cultured at 5 ppt and 30 ppt were lower than those cultured at 20 ppt after exposure to V. harveyi infection, suggesting that shrimp cultured at the two former salinity levels were more susceptible to V. harveyi infection. Network analysis also showed that shrimp cultured at 20 ppt exhibit a more stable bacterial network with complex interspecies interaction, even after induced by V. harveyi. Moreover, the presence of a high number of beneficial bacteria such as Pseudoruegeria, Rhodovulum, Ruegeria, Shimia and Lactobacillus in shrimp cultured at 20 ppt might have played a role in inhibiting the growth of V. harveyi and other potentially pathogenic bacteria. Besides, bacterial functional pathway prediction has also shown that metabolic pathways such as phenylalanine metabolism, glycine, serine and threonine metabolism, starch and sucrose metabolism, glyoxylate and dicarboxylate metabolism, carbon metabolism and biofilm formation process were significantly higher in shrimp cultured at 20 ppt. Collectively, our results suggested that 20 ppt is an optimal salinity that suppresses the growth of V. harveyi and potential pathogenic bacteria in the shrimp gut, which could possibly minimize the risk of pathogenic infection for sustainable production of healthy shrimp.

Abstract Background Climate is one of the most important driving factors of future changes in terrestrial, coastal, and marine ecosystems. Any changes in these environments can significantly influence physiological and behavioural responses in aquatic animals, such as crustacea. Crustacea play an integral role as subsistence predators, prey, or debris feeders in complex food chains, and are often referred to as good indicators of polluted or stressed conditions. They also frequently have high production, consumption, and commercial significance. However, crustacean’s responses to climate change are likely to vary by species, life-history stage, reproduction status and geographical distribution. This map is undertaken as part of the Long-Term Research Grant project which aims to identify any interactive effect on physiological compensation and behavioural strategy of how marine organisms, especially crustaceans, deal with stress from environmental change. Our proposed map will aim to outline the evidence currently existing for the impacts of climate change on the physiology and behaviour of important aquaculture crustacean species within Asia. Methods We will document peer-reviewed articles in English using published journal articles and grey literature. Two bibliographic databases (Scopus and Web of Science) and multiple organizational websites with Google scholars will be searched. The systematic map protocol will follow in accordance with the Collaboration for Environmental Evidence Guidelines and Standards. Literature will be screened at the title, abstract, and full-text level using pre-defined inclusion criteria. The map will highlight marine crustacea physiological compensation and behavioural strategies to cope with climate change. It will also improve our knowledge of the available evidence and current gaps for future research recommendations.