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Ecology
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For the journal, see Ecology (journal).
Ecology Portal
Eugenius Warming founded ecology as a scientific discipline
Ecology (from Greek: οίκος, oikos, "household"; and λόγος, logos, "knowledge") is the scientific study of the distribution and abundance of life and the interactions between organisms and their environment. The environment of an organism includes physical properties, which can be described as the sum of local abiotic factors such as insolation (sunlight), climate, and geology, and biotic factors, which are other organisms that share its habitat.
The word "ecology" is often used more loosely in such terms as social ecology and deep ecology and in common parlance as a synonym for the natural environment or environmentalism. Likewise "ecologic" or "ecological" is often taken in the sense of environmentally friendly.
The term ecology or oekologie was coined by the German biologist Ernst Haeckel in 1866, when he defined it as "the comprehensive science of the relationship of the organism to the environment."[1] Haeckel did not elaborate on the concept, and the first significant textbook on the subject (together with the first university course) was written by the Danish botanist, Eugenius Warming. For this early work, Warming is often identified as the founder of ecology.[2]
Contents
[hide]
1 Scope
1.1 Disciplines of ecology
2 History of ecology
3 Fundamental principles of ecology
3.1 Levels of ecological organization
3.2 Biosphere
3.3 The ecosystem concept
3.4 Dynamics and stability
3.5 Spatial relationships and subdivisions of land
3.6 Ecosystem productivity
3.7 Ecological crisis
4 Bibliography
5 References
6 See also
6.1 Lists
6.2 Related topics
7 External links
[edit] Scope
Ecology is usually considered a branch of biology, the general science that studies living organisms. Organisms can be studied at many different levels, from proteins and nucleic acids (in biochemistry and molecular biology), to cells (in cellular biology), to individuals (in botany, zoology, and other similar disciplines), and finally at the level of populations, communities, and ecosystems, to the biosphere as a whole; these latter strata are the primary subjects of ecological inquiry. Ecology is a multi-disciplinary science. Because of its focus on the higher levels of the organization of life on earth and on the interrelations between organisms and their environment, ecology draws heavily on many other branches of science, especially geology and geography, meteorology, pedology, genetics, chemistry, and physics. Thus, ecology is considered by some to be a holistic science, one that over-arches older disciplines such as biology which in this view become sub-disciplines contributing to ecological knowledge. In support of viewing ecology as a subject in its own right as opposed to a sub-discipline of biology, Robert Ulanowicz stated that "The emerging picture of ecosystem behavior does not resemble the worldview imparted by an extrapolation of conceptual trends established in other sciences."[3]
Agriculture, fisheries, forestry, medicine and urban development are among human activities that would fall within Krebs' (1972: 4) explanation of his definition of ecology: where organisms are found, how many occur there, and why.
Ecological knowledge such as the quantification of biodiversity and population dynamics have provided a scientific basis for expressing the aims of environmentalism and evaluating its goals and policies. Additionally, a holistic view of nature is stressed in both ecology and environmentalism.
Consider the ways an ecologist might approach studying the life of honeybees:
The behavioral relationship between individuals of a species is behavioral ecology — for example, the study of the queen bee, and how she relates to the worker bees and the drones.
The organized activity of a species is community ecology; for example, the activity of bees assures the pollination of flowering plants. Bee hives additionally produce honey which is consumed by still other species, such as bears.
The relationship between the environment and a species is environmental ecology — for example, the consequences of environmental change on bee activity. Bees may die out due to environmental changes (see pollinator decline). The environment simultaneously affects and is a consequence of this activity and is thus intertwined with the survival of the species.
[edit] Disciplines of ecology
Main article: Ecology (disciplines)
Ecology is a broad discipline comprising many sub-disciplines. A common, broad classification, moving from lowest to highest complexity, where complexity is defined as the number of entities and processes in the system under study, is:
Ecophysiology examines how the physiological functions of organisms influence the way they interact with the environment, both biotic and abiotic
Behavioral ecology examines the roles of behavior in enabling an animal to adapt to its environment
Population ecology studies the dynamics of populations of a single species.
Community ecology (or synecology) focuses on the interactions between species within an ecological community.
Ecosystem ecology studies the flows of energy and matter through the biotic and abiotic components of ecosystems.
Systems ecology is an interdisciplinary field focusing on the study, development, and organization of ecological systems from a holistic perspective.
Landscape ecology examines processes and relationship across multiple ecosystems or very large geographic areas.
Evolutionary ecology studies ecology in a way that explicitly considers the evolutionary histories of species and their interactions
Political ecology connects politics and economy to problems of environmental control and ecological change
Ecology can also be sub-divided according to the species of interest into fields such as animal ecology, plant ecology, insect ecology, and so on. Another frequent method of subdivision is by biome studied, e.g., Arctic ecology (or polar ecology), tropical ecology, desert ecology, etc. The primary technique used for investigation is often used to subdivide the discipline into groups such as chemical ecology, genetic ecology, field ecology, statistical ecology, theoretical ecology, and so forth. These fields are not mutually exclusive.
[edit] History of ecology
Main article: History of ecology
[edit] Fundamental principles of ecology
[edit] Levels of ecological organization
Ecology can be studied at a wide range of levels, from a large to small scale. These levels of ecological organization, as well as an example of a question ecologists would ask at each level, include:
Biosphere " What role does concentration of atmospheric Carbon Dioxide play in the regulation of global temperature?"
Region "How has geological history influenced regional diversity within certain groups of organisms?"
Landscape "How do vegetated corridors affect the rate of movement by mammals among isolated fragments?"
Ecosystem "How does fire affect nutrient availability in grassland ecosystems?"
Community "How does disturbance influence the number of mammal species in African grasslands?"
Interactions "What evolutionary benefit do zebras gain by allowing birds to remove parasites?"
Population "What factors control zebra populations?"
Individual "How do zebras regulate internal water balance?"
These levels range from broadest to most specific[4]
[edit] Biosphere
Main articles: Biosphere, Biodiversity, and Unified neutral theory of biodiversity
For modern ecologists, ecology can be studied at several levels: population level (individuals of the same species in the same or similar environment), biocoenosis level (or community of species), ecosystem level, and biosphere level.
The outer layer of the planet Earth can be divided into several compartments: the hydrosphere (or sphere of water), the lithosphere (or sphere of soils and rocks), and the
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