Secondary succession: trees are colonizing uncultivated fields and meadows.

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Ecological succession

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. The former case is often referred to as primary succession, the latter as secondary succession. Image File history File links File links The following pages link to this file: Ecological succession ... Image File history File links File links The following pages link to this file: Ecological succession ... Image File history File links Commons-logo. ... The Wikimedia Commons (also called Wikicommons) is a repository of free content images, sound and other multimedia files. ... This article or section does not cite any references or sources. ... In ecology, a community is an assemblage of populations of different species, interacting with one another. ... In computer programming jargon, lava flow is a problem in which computer code, usually written under less than optimal conditions, is put into production and then built on when still in a developmental state. ... In ecology, a disturbance is a temporary change in average environmental conditions that causes a pronounced change in ecosystem structure that lasts longer than the change in the environment. ... This article does not cite its references or sources. ... I love sum 41!!!!!!!!!! [[Image:[[Image:[[Image:[[Image:[[Image:[[Image:[[Image:[[Image:[[Image:[[Image:[[Image:[[Image:[[Image:[[Image:[[Image:[[Image: Trees are colonizing uncultivated fields and meadows Secondary succession is one of the two types of ecological succession of plant life. ...

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. Stochastic, from the Greek stochos or goal, means of, relating to, or characterized by conjecture; conjectural; random. ... Opportunism is a term mainly used in politics and political science. ... Look up fugitive in Wiktionary, the free dictionary. ... R-selected species (or opportunist species) is a term to describe a particular reproductive and survival strategy for organisms. ... K-selected species (or competitor species) is a term to describe reproductive and survival patterns in organisms. ...

Trends in ecosystem and community properties in succession have been suggested, but few appear to be general. For example, species diversity almost necessarily increases 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. Species diversity refers to the number and distribution of species in one location. ... To meet Wikipedias quality standards and make it easier to understand, this article or section may require cleanup. ... Switchgrass, a hardy plant used in the biofuel industry in the United States Rice chaff. ... In ecology, the trophic level (Greek trophē, food) is the position that an organism occupies in a food chain - what it eats, and what eats it. ...

Ecological succession was formerly seen as having a stable end-stage called the climax (see Frederic Clements), sometimes referred to as the 'potential vegetation' of a site, shaped primarily by the local climate. This idea has been largely abandoned by modern ecologists in favor of nonequilibrium ideas of how ecosystems function. Most natural ecosystems experience disturbance at a rate that makes a "climax" community unattainable. Climate change often occurs at a rate and frequency sufficient to prevent arrival at a climax state. Additions to available species pools through range expansions and introductions can also continually reshape communities. The term climax community is an ecological term for a community of plants and animals which is the result of succession, where a biological system, a community, or a soil has reached a steady state. ... Frederic Edward Clements (1874–1945) was an American plant ecologist and pioneer in the study of vegetation succession. ...

Many species are specialized to exploit disturbances. In forests of northeastern North America trees such as Betula alleghaniensis (Yellow birch) and Prunus serotina (Black cherry) are particularly well-adapted to exploit large gaps in forest canopies, but are intolerant of shade and are eventually replaced by other (shade-tolerant) species in the absence of disturbances that create such gaps. Binomial name Betula alleghaniensis Britt. ... Binomial name Prunus serotina Ehrh. ... Shade tolerance is an ecological concept that refers to plants abilities to tolerate low light levels. ...

The development of some ecosystem attributes, such as pedogenesis and nutrient cycles, are both influenced by community properties, and, in turn, influence further community development. This process may occur only over centuries or millennia. Coupled with the stochastic nature of disturbance events and other long-term (e.g., climatic) changes, such dynamics make it doubtful whether the 'climax' concept ever applies or is particularly useful in considering actual vegetation. Pedogenesis or soil evolution (formation) is the process by which soil is created. ...

The idea of ecological succession goes back to the 19th Century. In 1860 Henry David Thoreau read an address called "The Succession of Forest Trees" in which he described succession in an Oak-Pine forest. Alternative meaning: Nineteenth Century (periodical) (18th century — 19th century — 20th century — more centuries) As a means of recording the passage of time, the 19th century was that century which lasted from 1801-1900 in the sense of the Gregorian calendar. ... Henry David Thoreau (July 12, 1817 – May 6, 1862; born David Henry Thoreau[1]) was an American author, naturalist, transcendentalist, tax resister, development critic, and philosopher who is best known for Walden, a reflection upon simple living in natural surroundings, and his essay, Civil Disobedience, an argument for individual resistance...

Henry Chandler Cowles, at the University of Chicago, developed a more formal concept of succession, following his studies of sand dunes on the shores of Lake Michigan (the Indiana Dunes). He recognized that vegetation on sand-dunes of different ages might be interpreted as different stages of a general trend of vegetation development on dunes, and used his observations to propose a particular sequence (sere) and process of primary succession. His paper, "The ecological relations of the vegetation of the sand dunes of Lake Michigan" in 1899 in the Botanical Gazette is one of the classic publications in the history of the field of ecology. Henry Chandler Cowles (February 27, 1869 - September 12, 1939) was an American ecological pioneer. ... The University of Chicago is a private university located principally in the Hyde Park neighborhood of Chicago. ... Lake Michigan is one of the five Great Lakes of North America, and the only one in the group located entirely within the United States. ... Indiana Dunes National Lakeshore, a U.S. national lakeshore authorized by Congress in 1966, is located in Northwest Indiana. ...

The Indiana Dunes on Lake Michigan, which stimulated Cowles' development of his theories of ecological succession.

Understanding of succession was long dominated by the theories of Frederic Clements, a contemporary of Cowles, who held that successional sequences of communities (seres), were highly predictable and culminated in a climatically determined stable climax. Clements and his followers developed a complex taxonomy of communities and successional pathways (see article on Clements). On 2002-03-04 05:17:10, Kazik uploaded file indiana_dunes. ... On 2002-03-04 05:17:10, Kazik uploaded file indiana_dunes. ... Frederic Edward Clements (1874–1945) was an American plant ecologist and pioneer in the study of vegetation succession. ... The term climax community is an outdated ecological term for a community of plants and animals which is the result of succession, where a biological system, a community, or a soil has reached a steady state. ...

A contrasting view, the Gleasonian framework, is more complex, with three items: invoking interactions between the physical environment, population-level interactions between species, and disturbance regimes, in determining the composition and spatial distribution of species. It differs most fundamentally from the Clementsian view in suggesting a much greater role of chance factors and in denying the existence of coherent, sharply bounded community types. Gleason's ideas, first published in the early 20th century, were more consistent with Cowles' thinking, and were ultimately largely vindicated. However, they were largely ignored from their publication until the 1960s. Henry Allan Gleason (1882-1975) was a noted American ecologist, botanist, and taxonomist, most recognized for his endorsement of the individualistic hypothesis of ecological succession. ...

Beginning with the work of Robert Whittaker and John Curtis in the 1950s and 1960s, models of succession have gradually changed and become more complex. In modern times, among North American ecologists, less stress has been placed on the idea of a single climax vegetation, and more study has gone into the role of contingency in the actual development of communities. Robert Whittaker (1920-1980) was an American vegetation ecologist, active in the 1950s through the 1970s. ... Climax vegetation is the vegetation which establishes itself on a given site for given climatic conditions in the absence of anthropic action after a long time (it is the asymptotic or quasi equilibrium state of the local ecosystem). ... In philosophy and logic, contingency is the status of facts that are not logically necessary. ...

External links

• Biographical sketch of Henry Chandler Cowles.
• Robbert Murphy sees a significantly ideological, rather than scientific, basis for the disfavour shown towards succession by the current ecological orthodoxy and seeks to reinstate succession by holistic and teleological argument.
• Ecological Succession