Biological Sciences
Nutrient Cycles
Nutrient cycles refer to the movement and exchange of essential elements such as carbon, nitrogen, and phosphorus between the biotic and abiotic components of an ecosystem. These cycles involve processes like photosynthesis, respiration, decomposition, and nutrient uptake by plants. Nutrient cycles are crucial for sustaining life and maintaining ecological balance within ecosystems.
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11 Key excerpts on "Nutrient Cycles"
eBook - PDF- Shalinee Naidoo(Author)
- 2023(Publication Date)
- Delve Publishing(Publisher)
Environmental Science for Beginners 84 Figure 9: Overview of the cycling of water. NUTRIENT CYCLING The cycling of nutrients forms some of the most important processes that occur within an ecosystem as these cycles highlight the use, movement and recycling pathways within an environment. While elements such as carbon, oxygen, hydrogen, phosphorus, and nitrogen are essential in forming the basic building blocks of life, it should be remembered that there are also many other elements that are needed for the existence of living organisms. These elements are able to move between the abiotic and biotic spheres of an ecosystem in closed cycles which allow for recycling through various geological, biological and chemical cycles within the living biosphere, non-living lithosphere and hydrosphere. Within these cycles, plants take up carbon dioxide from the air and water while also utilizing minerals from the soil to aid in the production of carbohydrates, fats, and proteins thereby promoting growth and reproduction. From here, these carbohydrates, fats and proteins pass into the food chain and can be utilized by herbivores and carnivores before eventually returning to the abiotic environment when dead plant and animal tissue decomposes. Nutrient Cycles are more commonly known as biogeochemical cycles – the name of which perfectly illustrates the interconnectedness of these elements within the biological, geological and chemical spheres. The most commonly described and therefore important of the cycles are carbon, nitrogen, phosphorus and sulfur. These biogeochemical cycles can be broken down into two main types, namely local and global cycles. Local cycles involve the transfer of elements over Environmental Interactions, Cycles and Systems 85 long distances and global cycles in which elements are exchanged between the atmosphere and ecosystem.
eBook - PDF- Mohammad Waseemul Islam(Author)
- 2019(Publication Date)
- Delve Publishing(Publisher)
The organisms through the movement of nutrients accumulate the nutrients, which are usable to them. Therefore, Nutrient Cycles enable the provision of elements to organisms in forms that are usable to them. 6.4.2. Transfer of Elements from One Location to Another The Nutrient Cycles enable the movement of elements from one location to another. The nitrogen is mostly found in remote or unhabitable regions, which are far from living organism. The process of movement of nutrients enables the elements to flow from remote regions to the soil as for example, nitrogen. The Dynamics of Nutrients and Agricultural Ecosystem 161 • Functioning of Ecosystems : The humans constitute in the working of environment and cycle of nutrients support it. The environment requires the state of balance to work properly, back to the balanced state through the Nutrient Cycles. • Storage of Elements: The storing of elements is supported by the Nutrient Cycles. The elements in their natural shape flow are stored in natural storehouses and are released in small amounts to be eaten. For example, the plants can use nitrogen, as they required in small quantity even if it is available in sufficient quantity. • Link Organisms Both Living and Non-Living: The flow of nutrient connects living organisms with living organisms, living organisms with the non-living organisms and non-living organisms with non-living organisms. The life of a living organism and all organisms depend on each other, so it is important. The Nutrient Cycles have connected these organisms as they get nutrients from them. • Regulate the Flow of Substances: The movements of substances are controlled by Nutrient Cycles. The cycles of nutrients move through different spheres biosphere, lithosphere, atmosphere, and hydrosphere and the movement of elements is controlled at each sphere and has a specific medium and frequency at which the flow of elements is determined by the stickiness and compactness of the medium.
eBook - PDFThe Environment
Science, Issues, and Solutions
- Mohan K. Wali, Fatih Evrendilek, M. Siobhan Fennessy(Authors)
- 2009(Publication Date)
- CRC Press(Publisher)
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. Appropriately, Nutrient Cycles include only those macro- and microelements that are essential for biotic growth (see Chapters 4 and 5). Three groups of biogeochemical cycles are recognized: the hydrological (or water) cycle; gaseous cycles, which have gas, liquid, and solid phases (e.g., those of carbon, nitrogen, oxygen, and sulfur); and sedimentary or mineral cycles (e.g., iron, calcium, magnesium, and phosphorus), where relatively insoluble elements 98 The Environment: Science, Issues, and Solutions are taken up from the soil or water by plants, passed on to the herbivores and carnivores, and, through excretion, death, and decay, are returned to the soil or water. These have no atmospheric component. Drivers of Biogeochemical Cycles The flux of solar energy is the engine that powers the hydrologic cycle, drives the Earth’s climate patterns, and energizes the biogeo-chemical cycles. These cycles are crucial to the functioning and maintenance of the ecological processes that are requisite for the sustenance of life. As the name implies, the fluxes of bio-geochemical cycles are determined by several factors: climatic variables—particularly tem-perature and precipitation, the nature of the element (for example, its solubility or the dif-ferent forms it can take), and types and chemi-cal compositions of soils, plants, and animals. Nutrients can be lost from and carried into eco-systems by wind, precipitation, flowing water, and migrating animals, as well as by various forms of pollution, management practices, and land uses.
eBook - ePub- Pramod Kumar Pandey, Amit Pande(Authors)
- 2023(Publication Date)
- CRC Press(Publisher)
3 Nutrient Cycling in Aquatic EcosystemDOI: 10.1201/9781003313137-33.1 Introduction
The Earth is created with a finite number of chemical elements, and the only way more elements may be added is occasionally by meteorites striking the Earth from space. Chemicals are recycled throughout the Earth’s biological and geological cycles because they operate in a closed system and don’t dramatically increase or decrease in volume. These cycles affect the biosphere lithosphere, atmosphere, and hydrosphere, which are inert. The primary biogeochemical cycles explain how carbon, nitrogen, and phosphorus move through the environment.These substances move back and forth through the biosphere, lithosphere, hydrosphere, and atmosphere over time. Living beings can absorb and use them for reproduction and growth before passing them on to new organisms or re-entering one of the geospheres. The hydrosphere contains dissolved nutrients and gases such as PO4 3 -, NO3 , and CO2 , whereas the atmosphere contains gases such as CO2 and N2. The sedimentary and volcanic rocks include minerals such as carbonates, sulphates, or phosphates. Thus, the term biogeochemical cycles is commonly used to describe the exchange of nutrients and other elements between living organisms and non-living environments.Biogeochemical cycles may be classified as sedimentary cycles and gaseous cycles. The sedimentary cycle involves the decomposition of rocks and the erosion of minerals. In addition to their circulation in the environment, they eventually return to the Earth’s crust. The sedimentary cycles include iron, calcium, phosphorus, and other elements more closely associated with the Earth; for example, the phosphorus cycle, where the long-distance transfer mechanisms are absent. Biogeochemical cycles that involve air or the oceans are called gaseous cycles, as they are facilitated via evaporation. A gaseous cycle involves an exchange between the atmosphere and the environment. Some examples of gaseous cycles are nitrogen, oxygen, carbon, and water. Gaseous cycles tend to move faster than sedimentary cycles and respond more quickly to changes in the biosphere because the atmosphere is a vast reservoir. The nitrogen and the carbon cycles are two examples of the global Nutrient Cycles (gaseous cycles) that link the biosphere, or connected ecosystem, which includes the Earth and living beings.
eBook - PDF- Joachim Tourbier, Robert W. Pierson, Jr., Joachim Tourbier, Robert W. Pierson, Jr.(Authors)
- 2016(Publication Date)
7 Nutrient Cycles in Natural Systems: Microbial Involvement THOMAS L. BOTT Stroud Water Research Center Academy of Natural Sciences of Philadelphia Nutrient Cycles can be thought of as the conversion of nutrients from an inorganic form to an organic form and their return again to the inorganic state. The cycling of materials also in-volves changes from the particulate state to the dissolved, returning again to the particulate. In addition, nutrient cycling may involve exchange between subsystems of the biosphere. Nutrients move from terrestrial environments to aquatic habitats and from the atmosphere to aquatic en-vironments, and there are subsequent returns. There may also be exchanges within a subsystem, such as between the sediment and overlying water in a lake. Although bacteria and fungi comprise only a small part of the total biomass in any environ-ment, they are the essential organisms in nutrient cycling. Without microbial decomposition activity, nutrients would be permanently locked in plant and animal matter. The bacteria and fungi possess great metabolic versatility and uti-lize substrates, as nutrient and energy sources, that no other organisms can. Also, the bacteria in particular possess a high surface area: volume ratio and have extremely rapid meta-bolic rates. A single genus or closely related genera may be solely responsible for certain nutrient transformations; for example, the nitrifi-cation sequence. Note, however, that although they perform the biochemical conversions, the bacteria and fungi do not act alone in the mineralization of materials. There are a great many interactions with other microbes (such as the protozoa) and other forms (insect larvae or Zooplankton, for example) whereby rates of activity are accelerated or depressed. Higher forms, however, are dependent on the activity of the bacteria and fungi for continued existence.
eBook - PDFPhysiological Ecology of Forest Production
Principles, Processes and Models
- J. J. Landsberg, Peter Sands(Authors)
- 2010(Publication Date)
- Academic Press(Publisher)
The next section provides a general discussion of nutrient cycling; the remainder of the chapter deals in more detail with various components of the nutrient cycle and then with tree growth in relation to nutrition. 6.1 NUTRIENT CYCLING A simplified outline of nutrient cycling of a forest is presented in Figure 6.1. Switzer and Nelson (1972) proposed that the circulation of nutrients in forests be defined in terms of three cycles: geochemical cycles encompass the gains and losses of nutrients to the ecosystem by processes such as weathering and leaching; biogeochemical cycles encompass soil–plant relationships, including nutrient gains to the soil by symbiotic fixation, organic matter decomposition and losses by plant uptake; 154 Chapter 6 ‘biochemical’ cycles encompass internal transfer relationships or translocation of nutrients within the vegetation. (This term should not be confused with the biochemical cycling of organic compounds within the plant, for which we use the term ‘re-translocation’.) These cycles are labelled in Figure 6.1, and the processes involved in them are discussed in sequence below. The geochemical and biogeochemical cycles will be considered in relation to the volume of soil exploited by roots so that addition of nutrients to that volume, or their removal from it, is taken as gains or losses, respectively. We deal with the geochemical and biogeochemical cycles in the next sub-sections. Consideration of re-translocation is deferred to the section on forest nutritional requirements. 6.1.1. The Geochemical Cycle The geochemical cycle comprises the gains and losses of nutrients to the ecosystem by processes such as weathering and leaching. Geochemical processes are usually slow relative to the growth of trees. Nutrients are added to the soil by the weathering of parent materials, and in rainfall. Charley (1981) collated data on nutrient inputs in precipitation from a number of Australian sources.
eBook - PDF- 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.
eBook - PDF- 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.
eBook - PDF- Jose Galizia Tundisi, Takako Matsumura Tundisi(Authors)
- 2012(Publication Date)
- CRC Press(Publisher)
Biogeochemical cycles 10 SUMMARY The cycles of chemical elements and substances are interrelated with biological, geochemi-cal and physical processes. The distribution and concentration of elements and substances in water depend on ‘fixation’ and the active concentration of macronutrients (carbon, hydro-gen, nitrogen, phosphorus and sulphur) and micronutrients (magnesium, iron, copper and zinc). Macronutrients and micronutrients alike are found in living organic matter, particulate matter, decomposing matter, or dissolved in water. The nutrient recycling rate depends on the interactions between vertical and horizontal mixing and the activity and biomass of aquatic organisms. The vertical distribution of nutrients is affected by the vertical circulation in lakes or reser-voirs and depends on the type of circulation and its frequency. Bacteria with varying physiologi-cal and biochemical characteristics play a key role in biogeochemical cycles. Bottom sediment in rivers, lakes, reservoirs, estuaries and interstitial waters provide important quantitative and qualitative nutrient reserves. The availability of nutrients in sediment and interstitial waters depends on oxido-reductive processes and the anoxic or oxic layers of the sediment. Biogeochemical cycles are involved in the interactions of terrestrial and aquatic organisms. Aquatic macrophytes in the Corrego do Geraldo, UHE Carlos Botelho reservoir (Lobo/Broa). Photo : J. G. Tundisi. 348 Limnology 10.1 THE DYNAMICS OF BIOGEOCHEMICAL CYCLES As shown in Chapter 5, the composition of natural waters largely depends on the geochemistry of the water basin and the main characteristics and processes in the basin: soil types , uses and agricultural practices. In inland waters, the distribution of nutrients is also influenced by regenerative processes in the lake’s deepest layers and the sediment-water interface.
eBook - PDFEcology
Principles and Applications
- J. L. Chapman, M. J. Reiss(Authors)
- 1998(Publication Date)
- Cambridge University Press(Publisher)
THIRTEEN Nutrient cycling and pollution 13.1 The pattern of nutrient transfer and its connection with pollution As we discussed in Chapter 12, organisms need a supply of energy in order to survive, grow and repro- duce. They also, of course, need to obtain the elements of which they are composed (Figure 13.1). Energy transfer can be represented as a pyramid where each trophic level obtains less energy than the trophic level beneath it (Section 12.8). This is because at each trophic level of a food web most of the energy is lost from the community as the heat of respiration. This heat ends up in the physical envi- ronment and is rarely of direct use to organisms. This means that energy transfer is linear. Energy passes from the Sun to primary producers and so forth up the food web. The fundamental difference between energy trans- fer and nutrient transfer is that the pattern of nutri- ent transfer is basically circular or cyclical. The ele- ments which form the molecules of which organisms are made are unalterable in natural conditions on Earth, so they remain in circulation when molecules pass from one trophic level to another. They can be recycled over and over again. As Shakespeare put it 'Imperious Caesar, dead and turn'd to clay, might stop a hole to keep the wind away' (Hamlet, Act 5, H Li? Na K Mg Ca v a Cr Mo Mn Fe Co Ni a Cu Zn Cd? B p C Si Sn a Pb? N P As? O S Se a F a a Br? l a Figure 13.1 The elements required by organisms. The 11 shaded elements together account for 99.9% of the mass of most organisms. Elements marked 'p' are required only by plants; those marked 'a' only by animals. It is still unclear whether or not elements marked '?' are essential. 147 2 3 Nutrient cycling and pollution Scene 1). Usually, decomposers play a vital role in this nutrient cycling in returning small molecules and ions back from higher trophic levels to the soil, water or air, where they are available for reuse by the primary producers.
eBook - PDFThe Atmospheric Environment
Effects of Human Activity
- Michael B. Mcelroy(Author)
- 2021(Publication Date)
- Princeton University Press(Publisher)
Cycles of Nitrogen, Phosphorus, and Sulfur Living organisms require a variety of chemical elements for healthy growth. Carbon, hydrogen, oxygen, nitrogen, phosphorus, and sulfur constitute what may be called the macronutrients, the major elements of living organisms. The minor elements—the micronutrients—include sodium, magnesium, potassium, calcium, iron, manganese, fluorine, chlorine, and bromine. Our discussion of the carbon cycle in the preceding chapter outlined the impor- tance of carbon, hydrogen, and oxygen. Supplied in the form of CO 2 and H 2 O, these elements furnish the essential ingredients for photosynthesis. This chapter introduces the biogeochemical cycles regulating the supply of the other macronutrients: N, P, and S. We begin in Section 12.1 with a discussion of the nitrogen cycle. A major fraction of Earth’s nitrogen resides in the atmosphere as N 2 . In this form, how- ever, the element is relatively inaccessible to biological organisms. Before it can be incorporated in biological tissue, it must be fixed; meaning it must be trans- formed from the relatively inert form of N 2 to more accessible compounds such as NH 4 + and NO 3 – . A specific motivation in this Section is to understand the factors responsible for the rise in the abundance of N 2 O over the past sev- eral centuries. As previously noted, N 2 O is an important greenhouse gas. It also plays a critical role in the chemistry of the stratosphere. An increase in the abundance of N 2 O may be expected to result in an increase in the global aver- age temperature at Earth’s surface, accompanied by a drop in the abundance of O 3 in the stratosphere. The concentration of N 2 O is presently increasing at a rate roughly comparable to that of CO 2 : while the increase in CO 2 may be at- tributed mainly to combustion of fossil fuels, more subtle influences, it ap- pears, are responsible for the rise in N 2 O.
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