China
Africa
Explore chapters and articles related to this topic
Chemical Factors
Published in Michael J. Kennish, Ecology of Estuaries Physical and Chemical Aspects, 2019
The potential importance of nutrient cycling relative to nutrient input into estuaries is exemplified by Narragansett Bay, R.I. The nutrient budget for Narragansett Bay may be more complete than that of any other estuarine system described in the literature. Table 11 depicts the concentration of new and recycled nutrients in the bay which reflects the importance of nutrient cycling. The importance of recycling is particularly evident for ammonia, phosphate, and silicate-dissolved inorganic forms, which regulate primary production in the estuary.176
In Situ Cultivation of Artemisia annua
Published in Tariq Aftab, M. Naeem, M. Masroor, A. Khan, Artemisia annua, 2017
Inorganic manure is important for improving soil characteristics, including organic carbon and total nitrogen. If applied, organic matter improves soil structure, aeration, root penetration, water percolation, and efficiency in utilizing irrigation water. The addition of 20 t/ha of well-rotted manure has been recommended as both a short-term crop stimulant and a long-term measure to improve soil fertility (Rodriquez, 1986). Organic fertilizer, in addition to supplying nutrients, also improves the physicochemical condition of soils, enhancing nutrient cycling and building the soil’s organic matter resources. Animal dung also has a favorable effect on artemisinin content. Land application of sewage sludge enhances microbial activity that may affect soil cycling, and therefore influences plant metabolism. Application of animal dung and other compost improves the soil’s physical, biological, and chemical properties and their promotive effect on artemisinin content may be attributed to the release of nutrients, mainly nitrogen, which favors primary metabolism, growth, photosynthetic pigments, and nutrient status (Gandhi et al., 2000).
The Sustainability of the World's Soils
Published in Bill Pritchard, Rodomiro Ortiz, Meera Shekar, Routledge Handbook of Food and Nutrition Security, 2016
Stefan Hauser, Lindsey Norgrove
Recent surveys and stakeholder consultations across East, Central and West African countries revealed a strong interest of smallholders in integrating livestock into their farming systems. Although the reasons for such requests may vary, manure is a valuable source of organic matter and nutrients. Livestock integration is a measure to increase and potentially tighten nutrient cycles as well as accessing nutrient sources that would otherwise not become available for crop fields. Depending on the animal and its feed requirements, materials such as crop residues, weeds, unused fallow and ‘waste land’ vegetation are being used and returned as manure. The manner in which livestock is kept is decisive for the quantity and efficiency of nutrient cycling. Well-managed and corralled livestock would reduce losses to cropland and potentially increase nutrient stock depending on the proportion of feed foraged from outside the cropped area. Livestock may be a critical component to overcome problems of adoption of planted fallow systems (see the section in this chapter on Planted fallows) if the fallow can be used as forage specifically in phases when natural vegetation is short such as in dry seasons and short before the start of a cropping cycle. Corralling livestock on cover crop fields would ensure conversion to and retention of manure to improve soil quality and potentially reduce labour for land clearing and preparation before planting. Animals would improve food security, nutritional quality and income generation. However, a major constraint to their use in West and Central Africa include the presence of tsetse flies limiting the area suitable for cattle.
Physiotherapy and ecosystem services: improving the health of our patients, the population, and the environment
Published in Physiotherapy Theory and Practice, 2023
Jessica Stanhope, Filip Maric, Paul Rothmore, Philip Weinstein
Ecosystem services are the functions of an ecosystem that provide benefits to humans (Millennium Ecosystem Assessment, 2005), with the opposite being termed ecosystem disservices (Saunders, 2020). Both mitigation of the potentially harmful elements of the environment, and optimization of the benefits of exposure to the outdoor environment are reliant on ecosystems capable of providing corresponding ecosystem services. The Millennium Ecosystem Assessment (2005) divides such ecosystem services into four basic and not necessarily mutually exclusive categories: 1) provisioning services (e.g. production of food, clean water, and wood for fuel and construction); 2) regulating services (e.g. climate control and disease suppression); 3) cultural services (e.g. spirituality, sense of place, and recreation); and 4) supporting services (e.g. nutrient cycling and soil formation). Supporting services do not have a direct link with human health, but supporting services are required for the provisioning, regulating, and cultural services to occur.
Slime molds response to carbon nanotubes exposure: from internalization to behavior
Published in Nanotoxicology, 2021
Manon Ternois, Maxence Mougon, Emmanuel Flahaut, Audrey Dussutour
Due to its comparably simple structure in relation to its behavioral complexity and due to the ease with which it can be cultivated and manipulated, the acellular slime mold Physarum polycephalum presents itself as an ideal model system to determine the cytotoxicity of CNTs in single cell organisms. Physarum polycephalum is a remarkable organism belonging to the Myxomycetes and the Amoebozoa. It is a phagotrophic organism commonly observed in association with decaying plant material in terrestrial ecosystems. Physarum polycephalum, as a major component of the detritus food chain, is essential in nutrient cycling. Bacteria and fungi are the primary natural food source of P. polycephalum, and these are phagocytized (Aldrich 2012). Food particles are first captured in flask-like invaginations of the membrane and then isolated in vacuoles which are released into the cytoplasm. Physarum polycephalum can also take up droplets of medium by pinocytosis (Aldrich 2012). The vegetative state of P polycephalum is a large mobile polynucleated cell also called plasmodium. It can extend to up to hundreds of square centimeters (Figure 1(A)) and be severed into viable and structurally similar yet smaller plasmodia. Upon contact, these plasmodia can fuze with each other to form a unique plasmodium (Aldrich 2012). Lastly, a starving plasmodium can encapsulate and enter a dormant stage called sclerotium (Figure 1(C)).
Caenorhabditis elegans as a tool for environmental risk assessment: emerging and promising applications for a “nobelized worm”
Published in Critical Reviews in Toxicology, 2019
L. Queirós, J. L. Pereira, F. J. M. Gonçalves, M. Pacheco, M. Aschner, P. Pereira
Caenorhabditis elegans is a nematode of worldwide distribution in the wild. It is a small sized organism, with adults and its newly hatched larvae being 1 and 0.25 millimeters long, respectively. C. elegans can be isolated from organic-rich garden soils, compost, and rotting vegetable matter since these substrates contain bacteria and small eukaryotes that the nematode can use as a food resource (Corsi et al. 2015; Frézal and Félix 2015). The organism can also be recovered from snails (e.g. Helix aspersa), since associations of this nematode species with terrestrial gastropods and other small soil organisms are common (Caswell-Chen et al. 2005; Schulenburg and Félix 2017). More rarely, C. elegans can also be found living in aquatic ecosystems (Majdi and Traunspurger 2015; Rasch et al. 2016; Abu Khweek and Amer 2018). It was described in the waterfront of saprobic rivers in Germany, in freshwater habitats in Italy, and in aquatic biofilms in France (Kiontke 2006; Rasch et al. 2016). In fact, this species is abundant in microbe-rich environments (Schulenburg and Félix 2017). In the laboratory, the organism is normally cultured in agar plates with an added lawn of the bacterium Escherichia coli as food. In soil habitats, C. elegans has an important role in nutrient cycling and, consequently, in maintaining agricultural production, its sustainability and environmental quality, similarly to other soil invertebrates (Traunspurger et al. 1997; Höss et al. 1999; Lavelle et al. 2006).