Cycling of Materials in the Ecosystem

10 Key excerpts on "Cycling of Materials in the Ecosystem"

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  The 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.

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  Ecological Processes Handbook

  • Luca Palmeri, Alberto Barausse, Sven Erik Jorgensen(Authors)
  • 2013(Publication Date)
  • CRC Press

    (Publisher)

  187 12 Biogeochemical Cycles 12.1 Introduction The term biogeochemical cycle refers to the set of pathways involving bio-logical, geological, and chemical processes, by which a chemical element or substance moves through different environmental matrices (as discussed in Chapter 11). Common synonyms of biogeochemical cycle are turnover or cycling of substances (e.g., P or N cycling). Cycling means that, after a specific amount of time, the substance is found back in the starting phase and the set of pathways is then repeated. For example, circulation of chemical elements, such as carbon, oxygen, nitrogen, phosphorus, calcium, and water, through various ecospheres is referred to as biogeochemical cycle. Depending on the particular environmental conditions, various elements show characteristic cycling periods . While cycling throughout the ecospheres, an element may be accumulated in specific places, called reservoirs . For example, in aquatic ecosystems, phosphorus is often accumulated in the bottom sediment. Generally, reservoirs hold substances for times significantly longer than the cycling period. The length of time that a chemical is detained in one place is called its residence time . When chemicals are seized for a short period, they belong to exchange pools (e.g., plants and animals). Cycling time and storage time are critical factors defining the behavior and role of a particular sub-stance or element throughout its biogeochemical cycle. Ecologically relevant biogeochemical cycles are water, oxygen, carbon, nitrogen, phosphorus, and sulfur. Climate change and human impacts are drastically changing the speed, intensity, and balance of some relatively unknown cycles (e.g., the mercury cycle as well as the cycle of atrazine). Due to the troubling ecological implications, these cycles are increasingly studied.

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  Environment

  • David M. Hassenzahl, Mary Catherine Hager, Nancy Y. Gift, Linda R. Berg, Peter H. Raven(Authors)
  • 2018(Publication Date)
  • Wiley

    (Publisher)

  Detailed ecosystem studies such as those at HBEF also con- tribute to our practical knowledge about how to maintain water Courtesy Mark Green CHAPTER 4 quality, wildlife habitat, and productive forests. Ecosystem management, a conservation approach that emphasizes restor- ing and maintaining the quality of an entire ecosystem rather than the conservation of an individual species, makes use of such knowledge. The Cycling of Materials within Ecosystems LEARNING OBJECTIVES • Describe the main steps in each of these biogeochemical cycles: carbon, nitrogen, phosphorus, sulfur, and hydrologic. Chapter 3 described how energy flows in one direction through an ecosystem. In contrast, matter, the material of which or- ganisms are composed, moves through systems in numerous cycles from one part of an ecosystem to another—from one In Your Own Backyard… Identify an ecosystem near your home that has been affected by humans and is in need of ecosystem man- agement. What land-use changes have altered this par- ticular ecosystem? Catchment at Hubbard Brook Experimental Forest. A tower above the canopy of Hubbard Brook Experimental Forest is equipped with sensors that measure water, energy, and carbon dioxide fluxes in the ecosystem. 58 CHAPTER 4 Ecosystems and the Physical Environment organism to another and from living organisms to the abiotic en- vironment and back again (Figure 4.1 ). These biogeochemical cycles involve biological, geologic, and chemical interactions. Five biogeochemical cycles of matter—carbon, nitrogen, phosphorus, sulfur, and hydrologic (water)—are representa- tive of all biogeochemical cycles. These five cycles are partic- ularly important to organisms because these materials make up the chemical compounds of cells. Carbon, nitrogen, and sulfur are elements that form gaseous compounds, whereas water is a compound that readily evaporates; these four cycles have components that move over long distances in the atmosphere with relative ease.

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  From Populations to Ecosystems

  Theoretical Foundations for a New Ecological Synthesis

  • Michel Loreau(Author)
  • 2010(Publication Date)
  • Princeton University Press

    (Publisher)

  From a theoretical perspective, however, energy flows within ecosystems do not offer major new questions and challenges compared with the food-web perspective. Energy is transferred between organisms via trophic interactions and is gradually dissipated through respiration along the food chain. As a consequence, energy flows through the ecosystem from its fixation by photosynthesis to its dissipation by heterotroph respiration, with virtually no energy recycled within the ecosystem (figure 6.1, left). By contrast, material elements are heavily recycled within ecosystems. Material cycling is an inevitable consequence of energy flow in any physical system at equilibrium when material exchanges across its boundaries are limited (Morowitz 1966). Without recycling of materials in limited supply, energy flow would stop rapidly, leading to ecosystem collapse. Biologically, material cycling is likely to emerge spontaneously through evolution of organisms that use other organisms or their waste products as resources. The Earth system as a whole, including the biosphere, the atmosphere, the hydrosphere, and the lithosphere, is virtually a closed system except for negligible inputs of trace elements via meteorites. That is why biogeochemical cycles play a critical role in the functioning of the Earth system. But even at the scale of local ecosystems, nutrients such as nitrogen and phosphorus generally limit plant growth, and hence the productivity of the ecosystem as a whole because primary production is the process on which the entire trophic pyramid is built. Accordingly, nutrient cycling is a key process in the overall functioning of local ecosystems

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  Encyclopedia of Environmental Science Vol1

  Ecological Concepts and Environmental Science

  • Shalinee Naidoo(Author)
  • 2019(Publication Date)
  • Delve Publishing

    (Publisher)

  Ecological Concepts and Environmental Science 122 20.0. 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 35). Figure 35: Flow of usable and lost energy within the biosphere. Chemical nu-trients are continuously recycled between producers, consumers, decomposers and inorganic nutrient pool. Usable energy flows between the sun, producers, consumers and decomposers. Energy is also lost in the form of heat [Adapted from Eva Horne and Robert A Bear]. There are four distinct regions on the surface of the Earth and these are divided into the lithosphere (rocks forming the solid surface), hydrosphere (oceans, lakes, rivers, and icecaps), biosphere (community of living organisms) and atmosphere (air around us). Nutrients and materials move cyclically among these spheres. Many of these materials originate within the lithosphere in rocks. They are often released by weathering and subsequently enter water in the hydrosphere. From here, these nutrients are taken up by plants and enter animals and other organisms in the biosphere. They may then enter the atmosphere or re-enter water in hydrosphere. From here they can then enter the hydrosphere via oceans and be taken up by marine organisms. If these marine organisms from the biosphere are washed to the ground via rain, they are then returned to land. Ecological Concepts and Environmental Science 123 20.1. WHAT DRIVES BIOGEOCHEMICAL SYSTEMS? There are six commonly found elements that are present in a variety of chemical forms.

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  Global Ecology

  • Sven Erik Jørgensen(Author)
  • 2010(Publication Date)
  • Academic Press

    (Publisher)

  For such an abstract elementary cycle, the term ‘coenome’ can be used (for more details, see later). Food Webs Although biological cycling of each biogenic element is characterized by its own properties (see Carbon Cycle, Oxygen Cycle, Nitrogen Cycle, Phosphorus Cycle, Calcium Cycle, and Sulfur Cycle), all of the elements include migration of biomass in food webs. Transfer of the matter in the course of the cycling involves the following main steps: absorption and accumulation by living organisms of elements from abiotic environment; distribution of the matter among organisms as a result of herbivory, predation, and parasitism; territorial migration of organisms; formation of dead organic matter (DOM or mortmass) as a result of excretion and death of organisms; decomposition of the mortmass and return of the ele-ments to the abiotic environment. In accordance with the place, occupied by species in the food webs, they are usually divided into three main groups: producers (which use external energy, solar or inorganic chemical, and realize biosynthesis: generate organic mat-ter), consumers (which use chemical energy of living tissue of other organisms), and reducers (which use chemical energy of mortmass and do its biodegradation: decomposi-tion to simple inorganic agents). A classification of such organisms was initially proposed by A. L. Lavoisier in 1792 and then, in another form, was developed by W. Pfeffer in 1886. The main players in the nutrient cycling are produ-cers and reducers. The former are an ‘engine’ of the cycling; they involve elements from the abiotic environ-ment in the turnover and send them further in the composition of permanently generating high-energetic organic matter. The reducers ‘close’ the cycling; they return the ele-ments to the abiotic environment, where they can be used by producers again. Abiotic decomposition takes place, but its intensity is very low.

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  The Boreal Ecosystem

  • James A. Larsen, T. T. Kozlowski(Authors)
  • 2013(Publication Date)
  • Academic Press

    (Publisher)

  Nutrient Cycling and Productivity The biosphere is a regenerative system. Based on the utilization of incident solar energy, the capacity for renewal is an essential property. Life is maintained by the constant cycling of atmospheric gases and soil mineral nutrients and the ceaseless production of organic matter. The characteristics of biological systems have been shaped over the course of billions of years of evolution, and the cycling processes, it appears, are carried out with a great deal of efficiency, no doubt the consequence of evolutionary selection at work on the principal enzyme systems in-volved in the production of organic compounds. On a global basis, energy is seldom a limiting factor in the productivity of forest ecosys-tems; plant growth is more often critically influenced by the availability of nutrients and water. Nutrient elements occur in the atmosphere, the soil, rocks, and living and dead organic material. The atmosphere is the source of oxygen and carbon dioxide, as well as a major nutrient— nitrogen—occurring in gaseous form. Available mineral nutrients in soil are in the form of ions located either in humus or dissolved in the soil solution. There are minerals in inorganic materials and in rock, from both of which they are released by bacterial activity and by weathering processes. In the biogeochemical flux of elements, available soil and gaseous nutrients are taken up and assimilated by vegetation and mic-roorganisms and made available again through respiration, biological decomposition, and leaching from living and dead organic matter. Min-erals in soil and rock, converted to soluble available nutrients through weathering, enter the system and then are continually recycled. They enter an intrasystem cycle and tend to remain there, recycling, until finally they are washed away by the regional hydrological cycle, going into rivers and finally reaching the sea.

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  Ecology

  From Individuals to Ecosystems

  • Michael Begon, Colin R. Townsend, John L. Harper(Authors)
  • 2009(Publication Date)
  • Wiley-Blackwell

    (Publisher)

  18.1 Introduction Chemical elements and compounds are vital for the processes of life. Living organisms expend energy to extract chemicals from their environment, they hold on to them and use them for a period, then lose them again. Thus, the activities of organisms profoundly influence the patterns of flux of chemical matter in the biosphere. Physiological ecologists focus their attention on how individual organisms obtain and use the chemicals they need (see Chapter 3). However, in this chapter, as in the last, we change the emphasis and consider the ways in which the biota on an area of land, or within a volume of water, accumulates, transforms and moves matter between the various components of the ecosystem. The area that we choose may be that of the whole globe, a con- tinent, a river catchment or simply a square meter. 18.1.1 Relationships between energy flux and nutrient cycling The great bulk of living matter in any community is water. The rest is made up mainly of carbon compounds (95% or more) and this is the form in which energy is accumulated and stored. The energy is ultimately dissipated when the carbon compounds are oxidized to carbon dioxide (CO 2 ) by the metabolism of living tissue or of its decomposers. Although we consider the fluxes of energy and carbon in different chapters, the two are intimately bound together in all biological systems. Carbon enters the trophic structure of a community when a simple molecule, CO 2 , is taken up in photosynthesis. If it becomes incorporated in net primary productivity, it is available for consumption as part of a molecule of sugar, fat, protein or, very often, cellulose. It follows exactly the same route as energy, being successively consumed, defecated, assimilated and perhaps incorporated into secondary productivity somewhere within one of the trophic compartments.

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  Ecology

  From Ecosystem to Biosphere

  • Christian Leveque(Author)
  • 2003(Publication Date)
  • CRC Press

    (Publisher)

  Fortunately, organic matter is remineralized when organisms die, and these constituents return to the mineral state to be ultimately reused. The matter flows thus describe cycles between autotrophic organisms, heterotrophs, decomposers, and the physicochemical environment. Some essential principles need to be underlined in the study of biogeochemical cycles. • The various elements (e.g., water) or chemical elements (carbon, nitrogen, sulphur) are stored in what are called reservoirs (e.g., soil, oceans, atmosphere, lithosphere, biomass). There may be exchanges in the form of flows between these reservoirs (Fig. 13.1). For a long time, geochemistry, the study of the behaviour of chemical elements on the earth's surface, was devoted to the study and quantification of these exchanges. A good illustration of interactions between these various reservoirs is the oxygen cycle (Fig. 13.2), closely linked to that of carbon and water, since it is the essential source of free molecular oxygen resulting from photosynthesis. It is because of autotrophic plants that the air contains nearly 21% oxygen. A small part of this oxygen is transformed into ozone in the stratosphere (see Chapter 16). Another part serves to oxidize different mineral compounds and accumulates in the lithosphere. Another part is involved, most often through the aquatic ecosystems, in the formation of biogenic structures such as carbonaceous formations that sediment. 326 From Ecosystem to Biosphere Fig. 13.1. Biogeochemical cycles. Diagram of reservoirs of minerals and exogenous and endogenous cycles of exchanges between them. Fig. 13.2. Oxygen cycle: diagram of exchanges between reservoirs • Over the past few decades, it has been proven that the cycle of elements involves not only physicochemical processes. Living organisms are the source of an entire set of reactions that have long been unknown.

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  Soil Microbial Associations

  Control of Structures and Functions

  • V. Vancura, F. Kunc(Authors)
  • 2012(Publication Date)
  • Elsevier Science

    (Publisher)

  Typical examples of the first type a re the carbon a nd nitrogen cycles, while the phosphorus cycle is an example of the second t y p e. Carbon, nitrogen a nd mineral element s occur in the ecosystem s in soil, water, air a nd all biotic components . From each of these stores , pools or structures measured in space unit (m 2 , ha into the d e p th of 30 c m ), element s a re b e i ng transported either occassionally , periodically or continuousl y in amounts of n g, m g, g or kg, on a time-basi s of seconds , hours, days, y e a rs or e v en millenia to another p o ol or structure . The transpor t of these materials is c a l l ed a flow. I n d i v i d u al structures of ecosystem s a re interconnected by s u ch flows of matter a nd elements . The cycling t a k es p l a ce at all ecologica l levels. The o v e r a l l, global cycles p e r t a in to the transpor t of element s on a scale of the whole E a r th or the continents ( B U R NS a nd H A R D Y , 1975; S V E N S S ON a nd S Τ D E R L U N D , 1976; SCHLESINGER, 1977). Cycling at the level of regions, landscape s a nd administra-tive units is o f t en the object of economica l studies a nd analyses ( R O D I N a nd BASILEVITCH , 1974; KOLEK , 1977). In other cases , the cycles related to in-337 dividual t y p es of ecosystem s or to their p a r ts a re characterized ( R E I N O L D a nd D A I B E R , 1970; ULEHLOV Β et a l, 1976; C O U P L A N D a nd V A N D Y N E , 1979; T I T L Y A N O V A a nd BASILEVITCH , 1979). The intercellular, biochemica l changes , characterizing the c e l l u l ar level of i n d i v i d u al biotic component s of the ecosys -tems, c an affect strongly, or e v en predetermine , the overal characte r of the m a j or cycles ( F E N C H E L a nd B L A C K B U R N / 1 9 7 9 ).

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