Ecological Succession

10 Key excerpts on "Ecological Succession"

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  Subfields & Concepts of Ecology and Botany

  • (Author)
  • 2014(Publication Date)
  • Academic Studio

    (Publisher)

  ________________________ WORLD TECHNOLOGIES ________________________ Chapter 13 Ecological Succession Succession after disturbance: a boreal forest one (left) and two years (right) after a wildfire. Ecological Succession , a fundamental concept in ecology, refers to more or less predictable and orderly changes in the composition or structure of an ecological community. Succession may be initiated either by formation of new, unoccupied habitat ( e.g. , a lava flow or a severe landslide) or by some form of disturbance ( e.g. fire, severe windthrow, logging) of an existing community. Succession that begins in areas where no soil is initially present is called primary succession, whereas succession that begins in areas where soil is already present is called secondary succession. The trajectory of ecological change can be influenced by site conditions, by the interactions of the species present and by more stochastic factors such as availability of colonists or seeds, or weather conditions at the time of disturbance. Some of these factors contribute to predictability of successional dynamics; others add more probabilistic elements. In general, communities in early succession will be dominated by fast-growing, well-dispersed species (opportunist, fugitive, or r-selected life-histories). As succession proceeds, these species will tend to be replaced by more competitive (k-selected) species. Trends in ecosystem and community properties in succession have been suggested, but few appear to be general. For example, species diversity almost necessarily increases ________________________ WORLD TECHNOLOGIES ________________________ during early succession as new species arrive, but may decline in later succession as competition eliminates opportunistic species and leads to dominance by locally superior competitors. Net Primary Productivity, biomass and trophic level properties all show variable patterns over succession, depending on the particular system and site.

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  Important Subfields & Concepts of Ecology

  • (Author)
  • 2014(Publication Date)
  • The English Press

    (Publisher)

  ________________________ WORLD TECHNOLOGIES ________________________ Chapter- 2 Ecological Succession Succession after disturbance: a boreal forest one (left) and two years (right) after a wildfire. Ecological Succession , a fundamental concept in ecology, refers to more or less predictable and orderly changes in the composition or structure of an ecological community. Succession may be initiated either by formation of new, unoccupied habitat ( e.g. , a lava flow or a severe landslide) or by some form of disturbance ( e.g. fire, severe windthrow, logging) of an existing community. Succession that begins in areas where no soil is initially present is called primary succession, whereas succession that begins in areas where soil is already present is called secondary succession. The trajectory of ecological change can be influenced by site conditions, by the interactions of the species present and by more stochastic factors such as availability of colonists or seeds, or weather conditions at the time of disturbance. Some of these factors contribute to predictability of successional dynamics; others add more probabilistic elements. In general, communities in early succession will be dominated by fast-growing, well-dispersed species (opportunist, fugitive, or r-selected life-histories). As succession proceeds, these species will tend to be replaced by more competitive (k-selected) species. Trends in ecosystem and community properties in succession have been suggested, but few appear to be general. For example, species diversity almost necessarily increases ________________________ WORLD TECHNOLOGIES ________________________ during early succession as new species arrive, but may decline in later succession as competition eliminates opportunistic species and leads to dominance by locally superior competitors. Net Primary Productivity, biomass and trophic level properties all show variable patterns over succession, depending on the particular system and site.

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  Human Ecology

  Basic Concepts for Sustainable Development

  • Gerald G Marten, Gerald G. Marten(Authors)
  • 2010(Publication Date)
  • Routledge

    (Publisher)

  6 Ecological Succession

  Natural processes continually change ecosystems. The changes can take years or even centuries, working so slowly that they are scarcely noticed. They have a systematic pattern generated by community assembly, following an orderly progression know as Ecological Succession, another emergent property of ecosystems.

  Ecosystems change themselves and people change ecosystems. People change ecosystems to serve their needs. Intentional changes by people can set in motion chains of effects that lead to further changes – human-induced succession. Sometimes changes are unintended. They can be unwanted and they can be irreversible. This chapter will give three examples of human-induced succession:

  1. Overgrazing and pasture degradation.
  2. Overfishing and replacement of commercially valuable fish by trash fish.
  3. Severe forest fires when forests are protected from fires.

  Since Ecological Succession can be of immense practical consequence, humans have responded by developing a variety of ways in which to integrate their use of ecosystems with the natural processes of succession. Modern society uses intensive inputs to maintain agricultural and urban ecosystems by opposing the natural processes of Ecological Succession. Many traditional societies have drawn on centuries of experimentation and experience to develop strategies that take advantage of Ecological Succession in ways that allow them to use fewer inputs. This chapter will describe examples from traditional management of village forests and traditional agriculture.

  Ecological Succession                                              

  Do places with the same physical conditions always have exactly the same ecosystems? The answer is ‘no’. Firstly, random elements in biological community assembly can lead to different ecosystems. Secondly, ecosystems experience slow but systematic changes as community assembly proceeds. A single site has different biological communities, and therefore different ecosystems, at different times. The slow but orderly sequence of different biological communities at the same site is Ecological Succession

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  Ecosystem Collapse and Recovery

  • Adrian C. Newton(Author)
  • 2021(Publication Date)
  • Cambridge University Press

    (Publisher)

  7. The species composition of a site tends to equilibrate with the environment of that site. 8. The specific form of a successional trajectory is contingent on starting conditions, and the stochasticity of invasion and controls on species interactions. 9. Succession produces temporal gradients of the physical environ- ment, biotic communities and the interaction of the two. 48 · Ecological Theory Successional processes can be attributed to the response of individual species to disturbance, which will depend on the type and characteristics of the disturbance event and the attributes or life-history traits of the species present (Figure 2.2). For example, species differ in their traits relating to dispersal ability, establishment, growth, survival, reproduction and mortality on a particular site (Prach and Pyšek, 1999), which will influence their ability to colonise and persist in an area following disturb- ance. Analysis and classification of life-history traits has proved to be a successful approach for predicting responses of communities to disturb- ance, particularly in the case of terrestrial vegetation (Pulsford et al., 2016). Such approaches therefore offer a way of understanding how ecosystems recover. Succession was originally conceived as a progressive directional change in species composition, leading towards the creation of a stable climax community. Current conceptions recognise that succession is inherently variable and may follow many different pathways on a particular site (Box 2.4), owing to variation in factors including the characteristics of the disturbance event, the existence of resource gradients, the order in Figure 2.2 Mechanisms of Ecological Succession. Adapted from Pickett et al. (2013). 2.3 Succession · 49 which species colonise and the landscape context (Pickett et al., 2013).

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  Comparative Plant Succession among Terrestrial Biomes of the World

  • Karel Prach, Lawrence R. Walker(Authors)
  • 2020(Publication Date)
  • Cambridge University Press

    (Publisher)

  Part I Plant Succession and Biomes 2  Humans and Succession 2.1 Introduction Succession is a natural process of ecosystem development following a disturbance. In this chapter, we review basic theoretical concepts con- cerning succession and examine how humans have interacted with it. We document how human approaches to environmental change gradually became more formalized as a study of succession, a study that is now a dynamic tenet of ecology. We end the chapter with a discussion of how succession is currently studied. Humans have long been aware that their environment changes over time (Clements, 1916). Hunters and gatherers needed to know how seasonal variables such as leaf cover and frost duration or longer-term changes such as forest encroachment on grasslands affected their prey. They probably used fire to intentionally manipulate the proportion of woody plants and herbs. Farmers understood the implications of their short-term manipulations of soil fertility on longer-term soil quality and crop success and the implications of cutting down trees on forest regrowth. The development of early human societies depended on successful, sustainable harvesting of natural resources, so the focus was largely on practical management concerns. Therefore, humans have long influenced the natural forces driving succession. Throughout human history, we have consistently improved our ability to extract natural resources by clearing forests, draining wetlands, and mining raw materials. As humans became more efficient at resource extraction, these changes increased our role as manipulators of temporal dynamics. For example, the rapid expansion of humanity has intensified natural and anthropogenic disturbances; depleted populations of animals we hunt and fish; expanded and manipulated crops; facilitated the spread of nonnative plants; and created new plant communities better adapted to the changing environmental conditions (del Moral & Walker, 2007).

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  Fundamentals of Physical Geography

  • James Petersen, Dorothy Sack, Robert Gabler, , James Petersen, Dorothy Sack, Robert Gabler(Authors)
  • 2014(Publication Date)
  • Cengage Learning EMEA

    (Publisher)

  223 9 Biogeography and Soils :: Outline Ecosystems Succession and Climax Communities Environmental Controls Soils and Soil Development Factors Affecting Soil Formation Soil-Forming Regimes and Classification Ecosystems and Soils: Critical Natural Resources The living environment at the land surface and the soils below it are interdependent and intricately linked. The characteristics of one influences the characteristics of the other. Natural Resources Conservation Service Copyright 2013 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. 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. C H A P T E R 9 • B I O G E O G R A P H Y A N D S O I L S 224 these systems. Ecosystems are not isolated elements of nature; rather, they are usually closely related to nearby eco-systems and integrated with the larger ecosystems of which they are a part. The ecosystem concept is a valuable model for examining the structure and function of living communi-ties and their life forms. Ecosystem Components Despite their great variety on Earth, ecosystems typically have four basic components ( ■ Fig. 9.2). The first of these is the nonliving, or abiotic , parts of the ecosystem in which the plants and animals live. In a terrestrial ecosys-tem, the abiotic component provides life-supporting elements and compounds from the soil, the groundwater, and the atmosphere. Biogeography is the study of how environmental factors affect the locations, distributions, and life processes of plants and animals. Basically, this discipline seeks explanations for the geography of life forms.

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  Agroecology

  The Ecology of Sustainable Food Systems, Third Edition

  • Stephen R. Gliessman(Author)
  • 2014(Publication Date)
  • CRC Press

    (Publisher)

  Ecologists distinguish two basic types of succession. Primary succession is ecosystem development on sites (such as bare rock, glaciated surfaces, or recently formed volcanic islands) that were not previously occupied by living organ-isms or subject to the changes that the biotic components can bring to bear on the abiotic components. Secondary succes-sion is ecosystem development on sites that were previously occupied by living organisms, but had some or all of those organisms removed by fire, flooding, severe wind, intense grazing, or some other event. Depending on the intensity, fre-quency, and duration of the disturbance, the impact on the structure and function of the ecosystem will vary, as will the time required for recovery from the disturbance. Since the disturbance and recovery process that occur in agriculture usually take place in sites that formerly had other biotic com-ponents, we will focus our attention here on the secondary succession process. T HE N ATURE OF D ISTURBANCE Although natural ecosystems give the impression of being stable and unchanging, they are constantly being altered on some scale by events such as fire, wind storms, floods, extremes of temperature, epidemic outbreaks, falling trees, mudslides, and erosion. These events disturb ecosystems by killing organisms, destroying and modifying habitats, and changing abiotic conditions. Any of these impacts can change the structure of a natural ecosystem and cause changes in the population levels of the organisms present and the biomass they store. Disturbance can vary in three dimensions: 1. Intensity of disturbance can be measured by the amount of biomass removed or the number of indi-viduals killed. The three types of fire described in Chapter 10 provide good examples of variation in disturbance intensity: surface fires usually cre-ate low-intensity disturbance, whereas crown fires cause high-intensity disturbance.

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  Ecological Niches

  Linking Classical and Contemporary Approaches

  • Jonathan M. Chase, Mathew A. Leibold(Authors)
  • 2009(Publication Date)
  • University of Chicago Press

    (Publisher)

  However, there is considerable convergence between these approaches. In this section, we first focus on the mechanisms of the successional trajectory (species compositional change), assuming for sim-plicity that there is a single equilibrium. Then, we focus ex-plicitly on if and when alternative stable equilibria are ex-pected to exist due to differential historical processes. 123 1 2 4 c h a p t e r 8 Community Succession Since the seminal works of Cowles (1899), Clements (e.g., 1919, 1936), and Gleason (e.g., 1917, 1926, 1927), succession has held a prominent place in the study of community ecology. Generally, the concept of succession is applied to plant species, but similar ideas can be used for animal species. From the time a given community is estab-lished, its species composition goes through a series of stages, the last of which is generally thought to be the climax community. Graphical models of the niche framework can lend considerable insight into the process and patterns of succession. Here we discuss a subset of potential mechanisms of succession with strong empirical support: competition-colonization trade-offs, specialization on open spaces, and facilitation. In this section, we draw heavily on the previous work by Tilman (1982, 1985, 1988, 1990, 1994), as well as Pacala and Rees (1998). Competition-colonization trade-offs. This mechanism assumes that there is a trade-off among species in their ability to colonize new habitats and in their ability to consume resources and compete once in a habitat (Tilman 1990, 1994; Pacala and Rees 1998; Yu and Wilson 2001). In this scenario, when a new habitat is formed or an old habitat is cleared, the first species are able to disperse long distances and find those habi-tats. These species, the “pioneers,” grow and reproduce quite happily in the new habitat until species that are better competitors but poorer dispersers finally arrive. The climax community thus consists only of the best competitors.

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  International Perspectives on Global Environmental Change

  • Stephen S. Young, Steven E. Silvern, Stephen S. Young, Steven E. Silvern(Authors)
  • 2012(Publication Date)
  • IntechOpen

    (Publisher)

  Part 3 Biological Responses to Environmental Change 9 Primary Succession in Glacier Forelands: How Small Animals Conquer New Land Around Melting Glaciers Sigmund Hågvar Department of Ecology and Natural Resource Management, Norwegian University of Life Sciences, Aas, Norway 1. Introduction An easily observed effect of global warming is the gradual melting of glaciers in different parts of the world. Large areas of barren, pristine ground are left open for colonisation of various life forms (Fig. 1). From an ecological point of view, glacier forelands are interesting because they illustrate nature’s ability to recover from severe disturbance. Since the successive development of communities starts without previous life forms, it is a primary succession. In contrast, a secondary succession starts with a species assemblage already present, for instance on a forest patch after clear-cutting. While the botanical succession in glacier forelands has been well studied, the parallel zoological succession is less described and understood. Which animal species are pioneers, what properties make them pioneers, how fast does species number increase, and how do plants and animals interact during succession? An ecological understanding of primary succession is not only of scientific interest, but also helps us to predict future ecosystems in areas freed from the ice cover. 2. Glacier forelands: Nature’s ecological laboratory In some glacier forelands, glaciologists have followed the varying position of the ice edge during long time, sometimes supported by old photographs. The age of certain characteristic moraines can, for instance, be well dated, and the age of sites between may be estimated. Several European glaciers had a maximum size at the end of the “Little Ice Age”, which in Norway ended around A.D. 1750 with well-marked moraines. Forelands with dated sites up to 250 years age represent unique ecological laboratories for understanding nature’s ability to conquer new land.

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  Ecology

  From Individuals to Ecosystems

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

    (Publisher)

  (b) Percentage of individual trees in three successional categories. (c) Percentage of individual trees in various utility categories. Each data point is based on three replicate 1 ha plots. Different letters above each type of bar indicate statistically significant differences. (After Garcia-Fernandez et al., 2003.) ECOLOGICAL APPLICATIONS: MANAGEMENT OF COMMUNITIES AND ECOSYSTEMS 637 22.2.2 Managing succession for restoration The goal of restoration ecology is often a relatively stable successional stage (Prach et al., 2001) and ideally a climax. Once an undesirable land use ceases, managers need not intervene if they are prepared to wait for natural succession to run its course. Thus, abandoned rice fields in mountainous central Korea proceed from an annual grass stage (Alopecurus aequalis), through forbs (Aneilema keisak), rushes ( Juncus effusus) and willows (Salix koriyanagi), to reach a species-rich and stable alder woodland community (Alnus japonica) within 10 –50 years (Figure 22.4) (Lee et al., 2002). Succession cannot always be counted on to promote habitat restoration, especially if natural sources of seeds are small and distant, but this was not the case here. In fact, the only active intervention worth considering is the dismantling of artificial rice paddy levees to accelerate, by a few years, the early stages of succession. Meadow grasslands subject to agri- cultural intensification, including the application of artificial fertilizers and herbicides and heavy grazing regimes, have dramatically fewer plant species than grasslands under historic ‘traditional’ management. The restoration of biodiversity in these situations involves a sec- ondary succession that typically takes more than 10 years; it can be achieved by returning to a traditional regime without mineral fertilizer in which hay is cut in mid-July and cattle are grazed in the fall (Smith et al., 2003).

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