Geography
Material Cycles
Material cycles refer to the movement of materials such as carbon, nitrogen, and water through the Earth's systems. These cycles involve processes like photosynthesis, respiration, and decomposition, and play a crucial role in sustaining life on the planet. Understanding material cycles is important for managing natural resources and mitigating environmental impacts.
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5 Key excerpts on "Material Cycles"
- Bradley Striebig, Adebayo Ogundipe, Maria Papadakis, , Bradley Striebig, Adebayo Ogundipe, Maria Papadakis, , Bradley Striebig, Adebayo Ogundipe, Maria Papadakis(Authors)
- 2015(Publication Date)
- Cengage Learning EMEA(Publisher)
Due to electronic rights, some third party content may be suppressed from the eBook and/or eChapter(s). Editorial review has deemed that any suppressed content does not materially affect the overall learning experience. Cengage Learning reserves the right to remove additional content at any time if subsequent rights restrictions require it. 3.2 Biogeochemical Cycles 123 The anthropogenic (human-made) changes to the environment can be quanti-tatively described. The increase in the consumption of raw materials since 1900 is shown in Figure 3.2. This graph illustrates the increasing rate of consumption of raw materials as the world has industrialized. When the rate of consumption of natural resources exceeds the rate at which these resources can be regenerated, an unsus-tainable process is the result. The mass rate of material consumed can be compared to the mass rate of material being generated. If the mass rate of consumption is less than or equal to the mass rate of generation of that resource, then the process can be sustained indefinitely, or at least until the system changes. The mass of materials moving from one portion of the Earth to another can be measured, and the rates of production can be compared to the rate of consumption. Biogeochemical cycles describe the amount of material stored, produced, or consumed within a repository as well as the conversion of material from one repository to another. 3.2 Biogeochemical Cycles Elements such as carbon, oxygen, hydrogen, nitrogen, and phosphorus are prereq-uisites for life. However, an overabundance of any of these elements in different parts of the ecosystem can cause an imbalance in the system and produce unwanted changes. Biogeochemical cycles help us understand and interpret how chemicals interact in the environment.
eBook - PDF- Shalinee Naidoo(Author)
- 2023(Publication Date)
- Delve Publishing(Publisher)
ENVIRONMENTAL INTERACTIONS, CYCLES AND SYSTEMS CHAPTER14 All substances and materials found on the Earth’s surface are essential to life and form part of the biological and chemical cycles that sustain life. All physical and biological systems are characterized by energy and matter which are present in varying types within a respective system. In natural systems, both the energy and different forms of matter and conserved within a system meaning that while these forms can change, it cannot be created or destroyed. Within the environment are various interactions, nutrient cycles and systems; of which energy and matter pass through and interact. As they pass through, the different forms are able to interact with one another, either maximizing or minimizing the inputs and outputs relative to a given system. There is a range of processes and interactions that affect the transfer of substances and these include respiration, transportation, photosynthesis and decomposition in addition to a host of geological processes such as weathering, soil formation and sedimentation. Within the biosphere, lithosphere, atmosphere and hydrosphere, are several cycles that aid in maintaining the balance. The rate of human activities often disturbs and changes the natural flow of materials and energy and if these disturbances are large enough, it could lead to a shift and change in the levels of both local and global ecosystems. Environmental Science for Beginners 78 BIOGEOCHEMICAL CYCLES Energy flows in certain directions through the ecosystems of the Earth. It enters in the form of radiation energy from the Sun and exits in the form of heat while the chemical components are recycled. This inevitably means that the atoms cycling through the various spheres have been there for a very long time and have just been moving from one sphere to the next. Figure 8: The flow of usable and lost energy within the biosphere.
eBook - PDFThe Environment
Science, Issues, and Solutions
- Mohan K. Wali, Fatih Evrendilek, M. Siobhan Fennessy(Authors)
- 2009(Publication Date)
- CRC Press(Publisher)
97 Topics Biogeochemical Cycles Drivers of Biogeochemical Cycles Hydrological or Water Cycle Gaseous Cycles Mineral or Sedimentary Cycles Interactions of Biogeochemical Cycles 6 Biogeochemical Cycling of Materials Biogeochemical Cycles Biogeochemical cycles and energy flows establish not only the links among ecosystem components (biosphere, atmosphere, lithosphere, and hydrosphere) but also the link among ecosystems at local, regional, and global scales. Unlike energy that flows in one direction only, in nature, materials (including water) are cycled and reused within and among ecosystems over and over again. But together, the energy flow (energetics) and material cycling are the two funda-mental and complementary models of ecosystems (Reiners 1986). Within the biosphere, biogeochemical cycles describe how an element moves through the biotic and abiotic portion of an ecosys-tem. In doing so, both the transformation and transport of elements occur. The transport of elements can occur by the movement of wind, water, or animals. In some cases, cycling involves little move-ment—only a conversion from one form of a chemical to another (e.g., the uptake of nitrate by a plant and its conversion to an amino acid) or by a chemical reaction (e.g., the oxidation of methane in a lake to carbon dioxide and water by a bacterium). These relation-ships are often summarized in compartmental models, or “box and arrow” diagrams. These consist of compartments (or pools) repre-senting the mass of a given element in a particular chemical form and location. Compartments are connected to one another with links reflecting the movement of elements as they are transported or transformed between them. Because the cycles of materials involve biological, geological, and chemical components of an ecosystem, they are called biogeo-chemical cycles. In many cases, the cycles of elements are also referred to as nutrient cycles; however, all elements (including toxic elements) cycle in nature.
eBook - PDF- Sebastian Haumann, Martin Knoll, Detlev Mares, Sebastian Haumann, Martin Knoll, Detlev Mares(Authors)
- 2020(Publication Date)
- transcript Verlag(Publisher)
Material Flows and Circular Thinking Heike Weber For centuries, natural philosophers, scientists and engineers have referred to cer -tain natural and technical processes as ‘circulation’. Today, we speak of biogeo -chemical cycles of nutrients, nitrogen and phosphorus, of the circulation of blood in our bodies and of water in the wider ecosystem—to name but a few examples. Alchemists, physiologists and economic thinkers of the early modern period used the Latin term ‘circulatio’ , or the French and English term ‘circulation’ , to describe the transmutations and movements of materials, of bodily substances and fresh air, of commodities, traffic, wealth and money through entities such as nature, the body and the economy (Schramm 1997). In the 19th century, the borrowed term ‘Zirkulation’ entered the German language (Kilcher 2011), and circulation turned into the leading metaphor used to describe urban sanitation schemes. Since then, diverse fields of science and engineering have appropriated circulatory thinking in one way or another. The metaphor guides quantifying methods within bio-eco -nomics, ecosystem analysis and lifecycle analysis as well as geophysical thinking about longterm rock cycles and the ‘uranium fuel cycle’ of nuclear engineering (cf. Garcier 2012). More recently, the vision of a ‘circular economy’ has entered politics, industry and environmental activism in the context of a critique of consumer so -cieties’ wastefulness, and as a means of creating a sustainable society. Meanwhile the Anthropocene thesis claims that humans have irreversibly interrupted basic biogeochemical cycles and according to the geologist Peter Haf f, the earth has turned into a self-operating ‘technosphere’ (Otter in this volume). As this list demonstrates, the circulation trope is a common way to frame, but also to criticise the status quo of the socio-natural sphere as well as its ongoing transformations.
eBook - PDFEconomic Geographies
Circuits, Flows and Spaces
- Ray Hudson(Author)
- 2005(Publication Date)
- SAGE Publications Ltd(Publisher)
3 Flows of Materials, Transformations of Nature 3.1 Introduction The economy can be conceptualised as a series of material transformations and flows (biological, chemical and physical). These encompass extracting raw mate-rials from nature and converting them to socially useful resources, converting living plants and animals into inputs to production, selectively shaping these life forms via a variety of technologies, and consuming and eventually discarding the commodities produced. Such material transformations are marked by feedback loops, symptomatic of the complexity of interactions between people, nature and things and their diverse effects (both intended and unintended), and the emergent properties that characterise such complex systems. While the economy can be considered in terms of biological/chemical/physical transformations per se , these are shaped in specific ways by social relationships, and so vary within and between capitalist and other social relations. Consequently, while capitalist production involves the production of commodities, it can never be simply the production of commodities by means of commodities since at some point pro-duction necessarily involves appropriation from nature and the grounding of the economy in nature. 3.2 The economy as processes of material transformations and natural limits to economic life 3.2.1 Some basic concepts of material transformations Economic activity involves the application of human labour, deploying a variety of artefacts and tools, to transform and transport elements of nature to become socially useful products. However, these processes unavoidably give rise to unwanted by-products and wastes as inputs that do not emerge as desired products appear in these forms (Figure 3.1). Consequently, any form of production, transport and consumption has an environmental footprint (Jackson, 1995) and the economy can be conceptualised as flows of energy and chemical and physical transformations of elements of nature.
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