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81-547: The Society evolved out of the British Vegetation Committee, which was founded in 1904 to promote the survey and study of vegetation in the British Isles. This initiative was in turn the outcome of what many historians perceive to have been the emergence of modern ecology in the 1890s. The British Ecological Society's inaugural meeting was held at University College London on 12 April 1913 and

162-465: A dramatic effect on community structure. Hunting of sea otters, for example, is thought to have led indirectly to the extinction of the Steller's sea cow ( Hydrodamalis gigas ). While the keystone species concept has been used extensively as a conservation tool, it has been criticized for being poorly defined from an operational stance. It is difficult to experimentally determine what species may hold

243-428: A dramatic impact on the ecology of individual species or whole ecosystems. For instance, the replacement of an ant species by another (invasive) ant species has been shown to affect how elephants reduce tree cover and thus the predation of lions on zebras . A trophic level (from Greek troph , τροφή, trophē, meaning "food" or "feeding") is "a group of organisms acquiring a considerable majority of its energy from

324-497: A few species which are adapted to be able to survive in both salt and fresh water to be abundant. Inversely in land locked wetlands, the species abundance is more evenly distributed among the species who live within the wetland. In most ecosystems in which abundance has been calculated, most often only a small number of species are abundant, while a large number are pretty rare. These abundant species are often generalists , with many rare species being specialists . High density of

405-412: A flattened body relative to the main populations that live in open savanna. The population that lives in an isolated rock outcrop hides in crevasses where its flattened body offers a selective advantage. Habitat shifts also occur in the developmental life history of amphibians, and in insects that transition from aquatic to terrestrial habitats. Biotope and habitat are sometimes used interchangeably, but

486-612: A higher one." Small scale patterns do not necessarily explain large scale phenomena, otherwise captured in the expression (coined by Aristotle) 'the sum is greater than the parts'. "Complexity in ecology is of at least six distinct types: spatial, temporal, structural, process, behavioral, and geometric." From these principles, ecologists have identified emergent and self-organizing phenomena that operate at different environmental scales of influence, ranging from molecular to planetary, and these require different explanations at each integrative level . Ecological complexity relates to

567-444: A keystone role in each ecosystem. Furthermore, food web theory suggests that keystone species may not be common, so it is unclear how generally the keystone species model can be applied. Complexity is understood as a large computational effort needed to piece together numerous interacting parts exceeding the iterative memory capacity of the human mind. Global patterns of biological diversity are complex. This biocomplexity stems from

648-408: A keystone species can result in a community collapse just as the removal of the keystone in an arch can result in the arch's loss of stability. Sea otters ( Enhydra lutris ) are commonly cited as an example of a keystone species because they limit the density of sea urchins that feed on kelp . If sea otters are removed from the system, the urchins graze until the kelp beds disappear, and this has

729-741: A legacy niche that was constructed before their time. Biomes are larger units of organization that categorize regions of the Earth's ecosystems, mainly according to the structure and composition of vegetation. There are different methods to define the continental boundaries of biomes dominated by different functional types of vegetative communities that are limited in distribution by climate, precipitation, weather, and other environmental variables. Biomes include tropical rainforest , temperate broadleaf and mixed forest , temperate deciduous forest , taiga , tundra , hot desert , and polar desert . Other researchers have recently categorized other biomes, such as

810-439: A linear successional route, changes might occur quickly or slowly over thousands of years before specific forest successional stages are brought about by biological processes. An ecosystem's area can vary greatly, from tiny to vast. A single tree is of little consequence to the classification of a forest ecosystem, but is critically relevant to organisms living in and on it. Several generations of an aphid population can exist over

891-483: A low cost and also receive a discount on Open Access fees. The Society also partners with Wiley-Blackwell on the open access journal Ecology and Evolution . The society publishes the Ecological Reviews book series which aims to publish books on the cutting edge of modern ecology, providing a forum for current topics that are likely to be of long-term importance to the progress of the field In addition,

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972-439: A macroscopic view of the system. While the notion of trophic levels provides insight into energy flow and top-down control within food webs, it is troubled by the prevalence of omnivory in real ecosystems. This has led some ecologists to "reiterate that the notion that species clearly aggregate into discrete, homogeneous trophic levels is fiction." Nonetheless, recent studies have shown that real trophic levels do exist, but "above

1053-516: A mix of herbivores and predators). Omnivores do not fit neatly into a functional category because they eat both plant and animal tissues. It has been suggested that omnivores have a greater functional influence as predators because compared to herbivores, they are relatively inefficient at grazing. Trophic levels are part of the holistic or complex systems view of ecosystems. Each trophic level contains unrelated species that are grouped together because they share common ecological functions, giving

1134-420: A new appreciation for the influence that organisms have on the ecosystem and evolutionary process. The term "niche construction" is more often used in reference to the under-appreciated feedback mechanisms of natural selection imparting forces on the abiotic niche. An example of natural selection through ecosystem engineering occurs in the nests of social insects , including ants, bees, wasps, and termites. There

1215-435: A population-level phenomenon, as with the migration routes followed by plants as they occupied northern post-glacial environments. Plant ecologists use pollen records that accumulate and stratify in wetlands to reconstruct the timing of plant migration and dispersal relative to historic and contemporary climates. These migration routes involved an expansion of the range as plant populations expanded from one area to another. There

1296-400: A range of other specialist meetings, workshops, training events and field meetings. 51°31′21.97″N 0°6′54.93″W  /  51.5227694°N 0.1152583°W  / 51.5227694; -0.1152583 Ecology Ecology (from Ancient Greek οἶκος ( oîkos )  'house' and -λογία ( -logía )  'study of') is the natural science of

1377-401: A region), and sites are classed either as sources or sinks. A site is a generic term that refers to places where ecologists sample populations, such as ponds or defined sampling areas in a forest. Source patches are productive sites that generate a seasonal supply of juveniles that migrate to other patch locations. Sink patches are unproductive sites that only receive migrants; the population at

1458-517: A seasonal influx of new immigrants. A dynamic metapopulation structure evolves from year to year, where some patches are sinks in dry years and are sources when conditions are more favorable. Ecologists use a mixture of computer models and field studies to explain metapopulation structure. Community ecology examines how interactions among species and their environment affect the abundance, distribution and diversity of species within communities. Johnson & Stinchcomb (2007) Community ecology

1539-456: A species describes the environment over which a species is known to occur and the type of community that is formed as a result. More specifically, "habitats can be defined as regions in environmental space that are composed of multiple dimensions, each representing a biotic or abiotic environmental variable; that is, any component or characteristic of the environment related directly (e.g. forage biomass and quality) or indirectly (e.g. elevation) to

1620-411: A species distribution in which a few "core species" are wide spread, and the other species are restricted and scarce known as satellite species. Species abundance distribution (SAD) is one of the main uses of this measurement. SAD is a measurement of how common, or rare species are within an ecosystem. This allows researchers to assess how different species are distributed throughout an ecosystem. SAD

1701-433: A species in multiple localities will usually lead to it being relatively abundant over all in an ecosystem. Therefore, high local abundance can be directly linked to high regional distribution . Species with high abundance are likely to have more offspring, and these offspring in turn are more likely to colonize a new sector of the ecosystem than a species which is less abundant. Thus begins a positive feedback loop leading to

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1782-402: A specific habitat, such as a cave or a pond, and principles gleaned from small-scale studies are extrapolated to larger systems. Feeding relations require extensive investigations, e.g. into the gut contents of organisms, which can be difficult to decipher, or stable isotopes can be used to trace the flow of nutrient diets and energy through a food web. Despite these limitations, food webs remain

1863-446: A valuable tool in understanding community ecosystems. Food webs illustrate important principles of ecology : some species have many weak feeding links (e.g., omnivores ) while some are more specialized with fewer stronger feeding links (e.g., primary predators ). Such linkages explain how ecological communities remain stable over time and eventually can illustrate a "complete" web of life. The disruption of food webs may have

1944-403: A whole functional system, such as an ecosystem , cannot be predicted or understood by a simple summation of the parts. "New properties emerge because the components interact, not because the basic nature of the components is changed." Abundance (ecology) In ecology , local abundance is the relative representation of a species in a particular ecosystem . It is usually measured as

2025-399: A wide array of interacting levels of organization spanning micro-level (e.g., cells ) to a planetary scale (e.g., biosphere ) phenomena . Ecosystems, for example, contain abiotic resources and interacting life forms (i.e., individual organisms that aggregate into populations which aggregate into distinct ecological communities). Because ecosystems are dynamic and do not necessarily follow

2106-485: Is a central concept in the ecology of organisms and is sub-divided into the fundamental and the realized niche. The fundamental niche is the set of environmental conditions under which a species is able to persist. The realized niche is the set of environmental plus ecological conditions under which a species persists. The Hutchinsonian niche is defined more technically as a " Euclidean hyperspace whose dimensions are defined as environmental variables and whose size

2187-504: Is a function of the number of values that the environmental values may assume for which an organism has positive fitness ." Biogeographical patterns and range distributions are explained or predicted through knowledge of a species' traits and niche requirements. Species have functional traits that are uniquely adapted to the ecological niche. A trait is a measurable property, phenotype , or characteristic of an organism that may influence its survival. Genes play an important role in

2268-414: Is a larger taxonomy of movement, such as commuting, foraging, territorial behavior, stasis, and ranging. Dispersal is usually distinguished from migration because it involves the one-way permanent movement of individuals from their birth population into another population. In metapopulation terminology, migrating individuals are classed as emigrants (when they leave a region) or immigrants (when they enter

2349-726: Is a principal activity. The Journal of Ecology was first published in 1913 in time for the inaugural meeting of the Society, followed by the Journal of Animal Ecology (1932), Journal of Applied Ecology (1962), Functional Ecology (1987), and Methods in Ecology and Evolution (2010). In 2018, the society launched People and Nature , an Open Access interdisciplinary journal publishing work exploring relationships between humans and nature, followed by Ecological Solutions and Evidence in 2020. Members can subscribe to these journals at

2430-461: Is an emergent homeostasis or homeorhesis in the structure of the nest that regulates, maintains and defends the physiology of the entire colony. Termite mounds, for example, maintain a constant internal temperature through the design of air-conditioning chimneys. The structure of the nests themselves is subject to the forces of natural selection. Moreover, a nest can survive over successive generations, so that progeny inherit both genetic material and

2511-404: Is another statistical approach that is often used in conservation research . Metapopulation models simplify the landscape into patches of varying levels of quality, and metapopulations are linked by the migratory behaviours of organisms. Animal migration is set apart from other kinds of movement because it involves the seasonal departure and return of individuals from a habitat. Migration is also

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2592-522: Is calculated by dividing the number of species from one group by the total number of species from all groups. These measures are all a part of community ecology. Understanding patterns within a community is easy when the community has a relatively low number of species. However most communities do not have a low number of species. Measuring species abundance allows for understanding of how species are distributed within an ecosystem . For example, salt water marshes have an influx of sea water, causing only

2673-438: Is greater than respiration) by photosynthesis or chemosynthesis . Heterotrophs are organisms that must feed on others for nourishment and energy (respiration exceeds production). Heterotrophs can be further sub-divided into different functional groups, including primary consumers (strict herbivores), secondary consumers ( carnivorous predators that feed exclusively on herbivores), and tertiary consumers (predators that feed on

2754-432: Is one of the most basic measurements in ecology and is used very often, therefore many different methods of measurement and analysis have developed. There are several methods for measuring abundance. An example of this is Semi-Quantitive Abundance ratings. These are measurement methods which involve estimation based on viewing a specific area of a designated size. The two Semi-Quantitive Abundance ratings used are known as

2835-590: Is the Park Grass Experiment , which was initiated in 1856. Another example is the Hubbard Brook study , which has been in operation since 1960. Holism remains a critical part of the theoretical foundation in contemporary ecological studies. Holism addresses the biological organization of life that self-organizes into layers of emergent whole systems that function according to non-reducible properties. This means that higher-order patterns of

2916-413: Is the biosphere: the total sum of ecosystems on the planet. Ecological relationships regulate the flux of energy, nutrients, and climate all the way up to the planetary scale. For example, the dynamic history of the planetary atmosphere's CO 2 and O 2 composition has been affected by the biogenic flux of gases coming from respiration and photosynthesis, with levels fluctuating over time in relation to

2997-522: Is the study of the interactions among a collection of species that inhabit the same geographic area. Community ecologists study the determinants of patterns and processes for two or more interacting species. Research in community ecology might measure species diversity in grasslands in relation to soil fertility. It might also include the analysis of predator-prey dynamics, competition among similar plant species, or mutualistic interactions between crabs and corals. These ecosystems, as we may call them, are of

3078-556: Is used for managing wildlife stocks and setting harvest quotas. In cases where basic models are insufficient, ecologists may adopt different kinds of statistical methods, such as the Akaike information criterion , or use models that can become mathematically complex as "several competing hypotheses are simultaneously confronted with the data." The concept of metapopulations was defined in 1969 as "a population of populations which go extinct locally and recolonize". Metapopulation ecology

3159-405: The abundance or biomass at each level. When the relative abundance or biomass of each species is sorted into its respective trophic level, they naturally sort into a 'pyramid of numbers'. Species are broadly categorized as autotrophs (or primary producers ), heterotrophs (or consumers ), and Detritivores (or decomposers ). Autotrophs are organisms that produce their own food (production

3240-436: The logistic equation by Pierre Verhulst : where N(t) is the number of individuals measured as biomass density as a function of time, t , r is the maximum per-capita rate of change commonly known as the intrinsic rate of growth, and α {\displaystyle \alpha } is the crowding coefficient, which represents the reduction in population growth rate per individual added. The formula states that

3321-551: The Earth and atmospheric conditions within a narrow self-regulating range of tolerance. Population ecology studies the dynamics of species populations and how these populations interact with the wider environment. A population consists of individuals of the same species that live, interact, and migrate through the same niche and habitat. A primary law of population ecology is the Malthusian growth model which states, "a population will grow (or decline) exponentially as long as

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3402-421: The abundances of plant species are measured by plant cover , i.e. the relative area covered by different plant species in a small plot. Abundance is in simplest terms usually measured by identifying and counting every individual of every species in a given sector. It is common for the distribution of species to be skewed so that a few species take up the bulk of individuals collected. Relative species abundance

3483-744: The context of the environment. It encompasses life processes, interactions, and adaptations ; movement of materials and energy through living communities; successional development of ecosystems; cooperation, competition, and predation within and between species ; and patterns of biodiversity and its effect on ecosystem processes. Ecology has practical applications in conservation biology , wetland management, natural resource management ( agroecology , agriculture , forestry , agroforestry , fisheries , mining , tourism ), urban planning ( urban ecology ), community health , economics , basic and applied science , and human social interaction ( human ecology ). The word ecology ( German : Ökologie )

3564-714: The diversity of life from genes to ecosystems and spans every level of biological organization. The term has several interpretations, and there are many ways to index, measure, characterize, and represent its complex organization. Biodiversity includes species diversity , ecosystem diversity , and genetic diversity and scientists are interested in the way that this diversity affects the complex ecological processes operating at and among these respective levels. Biodiversity plays an important role in ecosystem services which by definition maintain and improve human quality of life. Conservation priorities and management techniques require different approaches and considerations to address

3645-530: The dynamic resilience of ecosystems that transition to multiple shifting steady-states directed by random fluctuations of history. Long-term ecological studies provide important track records to better understand the complexity and resilience of ecosystems over longer temporal and broader spatial scales. These studies are managed by the International Long Term Ecological Network (LTER). The longest experiment in existence

3726-456: The ecology and evolution of plants and animals. Ecological theory has also been used to explain self-emergent regulatory phenomena at the planetary scale: for example, the Gaia hypothesis is an example of holism applied in ecological theory. The Gaia hypothesis states that there is an emergent feedback loop generated by the metabolism of living organisms that maintains the core temperature of

3807-434: The energy is transferred through a chain of organisms by consumption. The simplified linear feeding pathways that move from a basal trophic species to a top consumer is called the food chain . Food chains in an ecological community create a complex food web. Food webs are a type of concept map that is used to illustrate and study pathways of energy and material flows. Empirical measurements are generally restricted to

3888-460: The environment experienced by all individuals in the population remains constant." Simplified population models usually starts with four variables: death, birth, immigration , and emigration . An example of an introductory population model describes a closed population, such as on an island, where immigration and emigration does not take place. Hypotheses are evaluated with reference to a null hypothesis which states that random processes create

3969-451: The equilibrium, r / α {\displaystyle r/\alpha } as K , which is known as the "carrying capacity." Population ecology builds upon these introductory models to further understand demographic processes in real study populations. Commonly used types of data include life history , fecundity , and survivorship, and these are analyzed using mathematical techniques such as matrix algebra . The information

4050-589: The flux of energy and matter through an environment. Ecosystems have biophysical feedback mechanisms that moderate processes acting on living ( biotic ) and abiotic components of the planet. Ecosystems sustain life-supporting functions and provide ecosystem services like biomass production (food, fuel, fiber, and medicine), the regulation of climate , global biogeochemical cycles , water filtration , soil formation , erosion control, flood protection, and many other natural features of scientific, historical, economic, or intrinsic value. The scope of ecology contains

4131-400: The former applies to a community's environment, whereas the latter applies to a species' environment. Definitions of the niche date back to 1917, but G. Evelyn Hutchinson made conceptual advances in 1957 by introducing a widely adopted definition: "the set of biotic and abiotic conditions in which a species is able to persist and maintain stable population sizes." The ecological niche

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4212-544: The former relates only to the physical modifications of the habitat whereas the latter also considers the evolutionary implications of physical changes to the environment and the feedback this causes on the process of natural selection. Ecosystem engineers are defined as: "organisms that directly or indirectly modulate the availability of resources to other species, by causing physical state changes in biotic or abiotic materials. In so doing they modify, maintain and create habitats." The ecosystem engineering concept has stimulated

4293-518: The full ecological scope of biodiversity. Natural capital that supports populations is critical for maintaining ecosystem services and species migration (e.g., riverine fish runs and avian insect control) has been implicated as one mechanism by which those service losses are experienced. An understanding of biodiversity has practical applications for species and ecosystem-level conservation planners as they make management recommendations to consulting firms, governments, and industry. The habitat of

4374-408: The herbivore trophic level, food webs are better characterized as a tangled web of omnivores." A keystone species is a species that is connected to a disproportionately large number of other species in the food-web . Keystone species have lower levels of biomass in the trophic pyramid relative to the importance of their role. The many connections that a keystone species holds means that it maintains

4455-406: The human and oceanic microbiomes . To a microbe , the human body is a habitat and a landscape. Microbiomes were discovered largely through advances in molecular genetics , which have revealed a hidden richness of microbial diversity on the planet. The oceanic microbiome plays a significant role in the ecological biogeochemistry of the planet's oceans. The largest scale of ecological organization

4536-404: The interplay among ecological processes that operate and influence patterns at different scales that grade into each other, such as transitional areas or ecotones spanning landscapes. Complexity stems from the interplay among levels of biological organization as energy, and matter is integrated into larger units that superimpose onto the smaller parts. "What were wholes on one level become parts on

4617-412: The interplay of development and environmental expression of traits. Resident species evolve traits that are fitted to the selection pressures of their local environment. This tends to afford them a competitive advantage and discourages similarly adapted species from having an overlapping geographic range. The competitive exclusion principle states that two species cannot coexist indefinitely by living off

4698-402: The latter focuses on materials and energy fluxes. System behaviors must first be arrayed into different levels of the organization. Behaviors corresponding to higher levels occur at slow rates. Conversely, lower organizational levels exhibit rapid rates. For example, individual tree leaves respond rapidly to momentary changes in light intensity, CO 2 concentration, and the like. The growth of

4779-424: The lifespan of a single leaf. Each of those aphids, in turn, supports diverse bacterial communities. The nature of connections in ecological communities cannot be explained by knowing the details of each species in isolation, because the emergent pattern is neither revealed nor predicted until the ecosystem is studied as an integrated whole. Some ecological principles, however, do exhibit collective properties where

4860-432: The lower adjacent level (according to ecological pyramids ) nearer the abiotic source." Links in food webs primarily connect feeding relations or trophism among species. Biodiversity within ecosystems can be organized into trophic pyramids, in which the vertical dimension represents feeding relations that become further removed from the base of the food chain up toward top predators, and the horizontal dimension represents

4941-558: The most various kinds and sizes. They form one category of the multitudinous physical systems of the universe, which range from the universe as a whole down to the atom. Tansley (1935) Ecosystems may be habitats within biomes that form an integrated whole and a dynamically responsive system having both physical and biological complexes. Ecosystem ecology is the science of determining the fluxes of materials (e.g. carbon, phosphorus) between different pools (e.g., tree biomass, soil organic material). Ecosystem ecologists attempt to determine

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5022-456: The nature of the unique physical environments that shapes the biodiversity within each. A more recent addition to ecosystem ecology are technoecosystems , which are affected by or primarily the result of human activity. A food web is the archetypal ecological network . Plants capture solar energy and use it to synthesize simple sugars during photosynthesis . As plants grow, they accumulate nutrients and are eaten by grazing herbivores , and

5103-573: The niche is called the ecotope , which is defined as the full range of environmental and biological variables affecting an entire species. Organisms are subject to environmental pressures, but they also modify their habitats. The regulatory feedback between organisms and their environment can affect conditions from local (e.g., a beaver pond ) to global scales, over time and even after death, such as decaying logs or silica skeleton deposits from marine organisms. The process and concept of ecosystem engineering are related to niche construction , but

5184-531: The number of nitrogen fixers , can lead to disproportionate, perhaps irreversible, changes in the system properties." Biodiversity refers to the variety of life and its processes. It includes the variety of living organisms, the genetic differences among them, the communities and ecosystems in which they occur, and the ecological and evolutionary processes that keep them functioning, yet ever-changing and adapting. Noss & Carpenter (1994) Biodiversity (an abbreviation of "biological diversity") describes

5265-474: The number of individuals found per sample . The ratio of abundance of one species to one or multiple other species living in an ecosystem is referred to as relative species abundances . Both indicators are relevant for computing biodiversity . A variety of sampling methods are used to measure abundance. For larger animals, these may include spotlight counts, track counts and roadkill counts, as well as presence at monitoring stations. In many plant communities

5346-399: The observed data. In these island models, the rate of population change is described by: where N is the total number of individuals in the population, b and d are the per capita rates of birth and death respectively, and r is the per capita rate of population change. Using these modeling techniques, Malthus' population principle of growth was later transformed into a model known as

5427-405: The opportunity for ecologists to present papers and posters on a wide variety of topics; an important element has always been the active participation of research students. There is an increasing number of delegates from overseas, principally Europe. It is Europe's largest annual meeting of ecologists. Since 1960 the Society has run an Annual Symposium and published a volume of its papers. It supports

5508-406: The organization and structure of entire communities. The loss of a keystone species results in a range of dramatic cascading effects (termed trophic cascades ) that alters trophic dynamics, other food web connections, and can cause the extinction of other species. The term keystone species was coined by Robert Paine in 1969 and is a reference to the keystone architectural feature as the removal of

5589-468: The published work of George Perkins Marsh ("Man and Nature"). Within an ecosystem, organisms are linked to the physical and biological components of their environment to which they are adapted. Ecosystems are complex adaptive systems where the interaction of life processes form self-organizing patterns across different scales of time and space. Ecosystems are broadly categorized as terrestrial , freshwater , atmospheric, or marine . Differences stem from

5670-502: The rate of change in population size ( d N ( t ) / d t {\displaystyle \mathrm {d} N(t)/\mathrm {d} t} ) will grow to approach equilibrium, where ( d N ( t ) / d t = 0 {\displaystyle \mathrm {d} N(t)/\mathrm {d} t=0} ), when the rates of increase and crowding are balanced, r / α {\displaystyle r/\alpha } . A common, analogous model fixes

5751-432: The relationships among living organisms and their environment . Ecology considers organisms at the individual, population , community , ecosystem , and biosphere levels. Ecology overlaps with the closely related sciences of biogeography , evolutionary biology , genetics , ethology , and natural history . Ecology is a branch of biology , and is the study of abundance , biomass , and distribution of organisms in

5832-424: The same limiting resource ; one will always out-compete the other. When similarly adapted species overlap geographically, closer inspection reveals subtle ecological differences in their habitat or dietary requirements. Some models and empirical studies, however, suggest that disturbances can stabilize the co-evolution and shared niche occupancy of similar species inhabiting species-rich communities. The habitat plus

5913-399: The site will disappear unless rescued by an adjacent source patch or environmental conditions become more favorable. Metapopulation models examine patch dynamics over time to answer potential questions about spatial and demographic ecology. The ecology of metapopulations is a dynamic process of extinction and colonization. Small patches of lower quality (i.e., sinks) are maintained or rescued by

5994-426: The society publishes a series of freely available short Better Science Guides on topics including Peer Review, Data Management, Interdisciplinary Research, Safe Fieldwork, Reproducible Code and Getting Published. The society also runs a photographic competition. The Society also runs several major scientific meetings for ecologists each year. The annual meeting currently attracts 1,200 delegates each year and provides

6075-524: The study of ecology into a conceptually manageable framework, the biological world is organized into a nested hierarchy , ranging in scale from genes , to cells , to tissues , to organs , to organisms , to species , to populations , to guilds , to communities , to ecosystems , to biomes , and up to the level of the biosphere . This framework forms a panarchy and exhibits non-linear behaviors; this means that "effect and cause are disproportionate, so that small changes to critical variables, such as

6156-432: The sum of the components explain the properties of the whole, such as birth rates of a population being equal to the sum of individual births over a designated time frame. The main subdisciplines of ecology, population (or community ) ecology and ecosystem ecology , exhibit a difference not only in scale but also in two contrasting paradigms in the field. The former focuses on organisms' distribution and abundance, while

6237-670: The tree responds more slowly and integrates these short-term changes. O'Neill et al. (1986) The scale of ecological dynamics can operate like a closed system, such as aphids migrating on a single tree, while at the same time remaining open about broader scale influences, such as atmosphere or climate. Hence, ecologists classify ecosystems hierarchically by analyzing data collected from finer scale units, such as vegetation associations , climate, and soil types , and integrate this information to identify emergent patterns of uniform organization and processes that operate on local to regional, landscape , and chronological scales. To structure

6318-415: The underlying causes of these fluxes. Research in ecosystem ecology might measure primary production (g C/m^2) in a wetland in relation to decomposition and consumption rates (g C/m^2/y). This requires an understanding of the community connections between plants (i.e., primary producers) and the decomposers (e.g., fungi and bacteria). The underlying concept of an ecosystem can be traced back to 1864 in

6399-439: The use of a location by the animal." For example, a habitat might be an aquatic or terrestrial environment that can be further categorized as a montane or alpine ecosystem. Habitat shifts provide important evidence of competition in nature where one population changes relative to the habitats that most other individuals of the species occupy. For example, one population of a species of tropical lizard ( Tropidurus hispidus ) has

6480-471: Was attended by 47 members. Sir Arthur Tansley became the first President and the first issue of Journal of Ecology was printed in time for the meeting. The Society faced several setbacks and was largely impacted by the events of World War I, as it formed the year prior to its beginning. In its early days the society shared the London offices of The Linnean Society . Publication of scientific journals

6561-593: Was coined in 1866 by the German scientist Ernst Haeckel . The science of ecology as we know it today began with a group of American botanists in the 1890s. Evolutionary concepts relating to adaptation and natural selection are cornerstones of modern ecological theory . Ecosystems are dynamically interacting systems of organisms, the communities they make up, and the non-living ( abiotic ) components of their environment. Ecosystem processes, such as primary production , nutrient cycling , and niche construction , regulate

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