Determining the Recoverable Geothermal Resources Using a Numerical Thermo-Hydraulic Coupled Modeling in Geothermal Reservoirs

Recoverable geothermal resources are very important for geothermal development and utilization. Generally, the recovery factor is a measure of available geothermal resources in a geothermal field. However, it has been a pre-determined ratio in practice and sustainable utilization of geothermal resources was not considered in the previous calculation of recoverable resources. In this work, we have attempted to develop a method to calculate recoverable geothermal resources based on a numerical thermo-hydraulic coupled modeling of a geothermal reservoir under exploitation, with an assumption of sustainability. Taking a geothermal reservoir as an example, we demonstrate the effectiveness of the method. The recoverable geothermal resources are 6.85 × 1018 J assuming a lifetime of 100 years in a well doublet pattern for geothermal heating. We further discuss the influence of well spacing on the recoverable resources. It is found that 600 m is the optimal well spacing with maximum extracted energy that conforms to the limit of the pressure drop and no temperature drop in the production well. Under the uniform well distribution pattern for sustainable exploitation, the recovery factor is 26.2%, which is higher than the previous value of 15% when depending only on lithology. The proposed method for calculating the recoverable geothermal resources is instructive for making decisions for sustainable exploitation.

Pharmacological Activities of Extracts and Compounds Isolated from Mediterranean Sponge Sources

Marine pharmacology is an exciting and growing discipline that blends blue biotechnology and natural compound pharmacology together. Several sea-derived compounds that are approved on the pharmaceutical market were discovered in sponges, marine organisms that are particularly rich in bioactive metabolites. This paper was specifically aimed at reviewing the pharmacological activities of extracts or purified compounds from marine sponges that were collected in the Mediterranean Sea, one of the most biodiverse marine habitats, filling the gap in the literature about the research of natural products from this geographical area. Findings regarding different Mediterranean sponge species were individuated, reporting consistent evidence of efficacy mainly against cancer, infections, inflammatory, and neurological disorders. The sustainable exploitation of Mediterranean sponges as pharmaceutical sources is strongly encouraged to discover new compounds.

Medicinal-Cosmetic Potential of the Local Endemic Plants of Crete (Greece), Northern Morocco and Tunisia: Priorities for Conservation and Sustainable Exploitation of Neglected and Underutilized Phytogenetic Resources

Medicinal-aromatic plants (MAPs) are important sources for the development of new valuable products of interest to human and animal health, and are also used as ornamentals for the horticulture industry. However, the increased global demand and the uncontrolled exploitation of these plants constitute a threat to their sustainability. To date, few scientific investigations have focused on MAPs valorization and their domestication. The purpose of this study was to evaluate for the first time the medicinal-cosmetic potential of 399 local endemic Mediterranean plants confined to Crete (223 taxa), the Mediterranean coast-Rif of Morocco (94), and Tunisia (82). The new methodological scheme was developed by experts through three multidisciplinary co-creative workshops and was adjusted by end-users to point-scoring of nine attributes evaluating the potential of the targeted neglected and underutilized plants (NUPs) in the medicinal-cosmetic sector. The results were demonstrated as percentage of the maximum possible score. These assessments were further linked and discussed with respect to feasibility and readiness timescale evaluations for sustainable exploitation of the focal NUPs. A great diversity of local endemic NUPs (30 taxa, 11 families) were associated with interesting medicinal-cosmetic properties (>35% up to 94.44%). Among them, 8 taxa showed the highest medicinal-cosmetic potential (>55% of maximum possible score), half of which are threatened with extinction. Although ex-situ conservation efforts and applied research work are needed to safeguard and unlock the full potential of the local endemic NUPs evaluated herein, the proposed multifaceted evaluation scheme revealed that some local endemic NUPs of the studied regions can be sustainably exploited in short- or medium-term, following successful examples of Cretan NUPs e.g., Origanum dictramnus. The sustainable exploitation of high scored taxa of the studied regions can be fastened through targeted species-specific research bridging extant research gaps and facilitating conservation and stakeholder attraction.

Molecular Authentication, Phytochemical Evaluation and Asexual Propagation of Wild-Growing Rosa canina L. (Rosaceae) Genotypes of Northern Greece for Sustainable Exploitation

Dogroses belong to a taxonomically difficult genus and family and represent important phytogenetic resources associated with high ornamental, pharmaceutical-cosmetic and nutritional values, thus suggesting a potentially high exploitation merit. Triggered by these prospects, wild-growing Rosa canina populations of Greece were selected for investigation and evaluation of their potential for integrated domestication. We collected ripe rosehips from Greek native wild-growing populations (samples from seven genotypes) for phytochemical analysis (total phenolics, total flavonoids, antioxidant activity and vitamin C content), leaf samples for DNA analysis using the ITS2 sequence (nine genotypes) and fresh soft-wood stem cuttings for propagation trials (seven genotypes). After evaluation of these materials, this study reports for the first-time distinct DNA-fingerprinted genotypes from Greece with interesting phytochemical profiles mainly in terms of Vitamic C content (up to 500.22 ± 0.15 mg of ascorbic acid equivalents/100 g of sample) as well as effective asexual propagation protocols for prioritized R. canina genotypes via cuttings. The latter highlights the importance of the levels of external hormone application (2000 ppm of indole-3-butyric acid), the effect of season (highly-effective spring trials) and genotype-specific differences in rooting capacities of the studied genotypes. All inclusive, this study offers new artificially selected material of Greek native R. canina with a consolidated identity and interesting phytochemical profile. These materials are currently under ex-situ conservation for further evaluation and characterization in pilot field studies, thus facilitating its sustainable exploitation for applications in the agro-alimentary, medicinal-cosmetic, and ornamental sectors.

GIS-Facilitated Seed Germination and Multifaceted Evaluation of the Endangered Abies marocana Trab. (Pinaceae) Enabling Conservation and Sustainable Exploitation

In the frame of the sustainable use of neglected and underutilized phytogenetic resources, and along with numerous studies in Abies spp. due to the innate conservation value of fir forests, this research focused on the Moroccan endemic fir, Abies marocana. The aim was triple-fold: to assess its potential and dynamics in economic sectors for sustainable exploitation; to determine the ecological conditions in which the species naturally thrives; and to find the appropriate requirements for its successful seed germination. We sourced multifaceted evaluations for three economic sectors performed in three levels, using 48 attributes and eight criteria from previous studies of our own, and the relevant species-specific assessments are overviewed herein in detail. The species’ ecological profile was constructed using Geographical Information Systems (GIS) and open access data (Worldclim). Seed germination trials were performed to examine the effect of cold stratification (non-stratified, one- and two-months stratified seeds), the influence of four temperatures (10 °C, 15 °C, 20 °C, and 25 °C), and interactions thereof in relation to germination percentage (GP) and mean germination time (MGT). The experiments showed that the interaction of cold stratification and germination temperature has a strong effect on the GP and MGT of A. marocana seeds. A detailed GIS-derived ecological profile of the focal species was created in terms of precipitation and temperature natural regimes, enabling the interpretation of the seed germination results. The multifaceted evaluations reveal an interesting potential of the Moroccan fir in different economic sectors, which is mainly compromised due to extant research gaps, unfavorable conditions, and low stakeholder attraction. The findings of this study fill in extant research gaps, contribute to in situ and ex situ conservation strategies, and can facilitate the sustainable exploitation of this emblematic local endemic plant of northern Morocco.

Socioeconomic impacts of sand harvesting along the Sanaga River in Nkol’Ossananga locality (Yaoundé-Cameroon): a vision toward a mechanized operation for sustainable exploitation

This paper presents the impacts of Nkol’Ossananga sand harvesting on social live and local economy based on field investigations and data analysis. Laboratory analysis of sand samples from the site has shown that the cleanliness of the Nkol’Ossananga sand nears 100%. This means that Nkol’Ossananga sand is pure and clean, most appropriate for house constructions and building engineering. The activity produces incomes to all actors of the chain value and government. Incomes generated are used by artisans to build their houses, buy some electronic devices, and take care of their families or to capitalize in their business investigation. In spite of the positive impacts presumed, Nkol’Ossananga sand harvesting also stands as the origin of many negative impacts including cultural brewing, delinquency, precocious abandon of studies and abandon of agriculture. The exploitation is done with rudimentary tools and poor technics thereby exposing artisans to several risks and illnesses. For sustainable exploitation, a mechanized operation has to be implemented. This kind of exploitation is the one that will improve the working conditions, increase production and incomes of workers as similar as that of government, and also reduces negative environmental impacts. Key words: Nkol’Ossananga sand, rudimentary tools and poor technics, incomes, negative impacts, sustainable exploitation, mechanized operation. Cet article présente les impacts sociaux et économiques de l’exploitation artisanale du sable de Nkol’Ossananga sur la base d’enquêtes de terrain et d’analyses de données. L’analyse en laboratoire des échantillons de sable collectés sur le site a montré que la propreté du sable de Nkol’Ossananga avoisine 100%. Ce qui signifie que le sable de Nkol’Ossananga est approprié pour le BTP et le génie civil. L'activité génère des revenus importants à tous les acteurs de la chaîne de production et le gouvernement. Les revenus générés sont utilisés par les artisans pour se faire construire leur maison d’habitation, acheter des appareils électroniques, prendre soin de leur famille ou alors sont capitalisés dans le commerce. Malgré les impacts positifs susmentionnés, l’exploitation artisanale du sable de Nkol’Ossananga est également source du brassage culturel, de la délinquance juvénile et de l’abandon précoce des études. Pour une exploitation durable, l’exploitation semi-mécanisée est envisageable. Ce type d'exploitation est celui qui pourra améliorer les conditions de travail des artisans, augmenter leur production et leurs revenus au même titre que ceux du gouvernement, et réduira par ricochet les impacts négatifs.

Status stock and Sustainable Management Measures for Moroccan Sardines

This article summarizes the state of stocks of sardine, sardina pilchardus in Moroccan waters at the end of 2016 and 2018. These stocks varies according to the region,They are now in a sustainable exploitation situation:Atlantic sardine, but also stocks that have reached or are still in over-exploitation levels: Mediterranean sardine. The fi shing pressure exerted on the sardine stock exceeds the optimal level by 40%. Due to the degradation of the fragile marine environment of the Mediterranean region, generated by pollution of various origins, the overexploitation of juveniles in the coastal strip, non-responsible practices and the use of non-fi shing gearselective, it is imperative to take the necessary measures to protect the marine environment and ensure rational and sustainable exploitation of the resource. (High commission plan 2006 report).

A Primer of Life Histories

Life histories describe how genotypes schedule their reproductive effort throughout life in response to factors that affect their survival and fecundity. Life histories are solutions that selection has produced to solve the problem of how to persist in a given environment. These solutions differ tremendously within and among species. Some organisms mature within months of attaining life, others within decades; some produce few, large offspring as opposed to numerous, small offspring; some reproduce many times throughout their lives while others die after reproducing just once. The exponential pace of life-history research provides an opportune time to engage and re-engage new generations of students and researchers on the fundamentals and applications of life-history theory. Chapters 1 through 4 describe the fundamentals of life-history theory. Chapters 5 through 8 focus on the evolution of life-history traits. Chapters 9 and 10 summarize how life-history theory and prediction has been applied within the contexts of conservation and sustainable exploitation. This primer offers an effective means of rendering the topic accessible to readers from a broad range of academic experience and research expertise.