ecosystems

(noun)

Communities of living organisms (plants, animals and microbes) in conjunction with the nonliving components of their environment (things like air, water, and mineral soil), interacting as a system; linked together through nutrient cycles and energy flows.

Related Terms

Examples of ecosystems in the following topics:

  • Studying Ecosystem Dynamics

    • Ecosystem dynamics is the study of the changes in ecosystem structure caused by environmental disturbances or by internal forces.
    • Various research methodologies measure ecosystem dynamics.
    • A holistic ecosystem model attempts to quantify the composition, interaction, and dynamics of entire ecosystems.
    • A food web is an example of a holistic ecosystem model, which is the most representative of the ecosystem in its natural state.
    • A major limitation to these approaches is that removing individual organisms from their natural ecosystem or altering a natural ecosystem through partitioning may change the dynamics of the ecosystem.

  • Ocean Ecosystems

  • Modeling Ecosystem Dynamics

    • Conceptual models describe ecosystem structure, while analytical and simulation models use algorithms to predict ecosystem dynamics.
    • For example, in a terrestrial ecosystem near a deposit of coal, carbon will be available to the plants of this ecosystem as carbon dioxide gas in a short-term period, not from the carbon-rich coal itself.
    • Since human impact can greatly and rapidly alter the species content and habitat of an ecosystem, it is crucial for scientists to develop models that predict how ecosystems respond to these changes.
    • However, their accuracy is limited by their simplification of complex ecosystems.
    • Conceptual models are useful for describing ecosystem structure, but are limited by their poor prediction of ecosystem changes.

  • Hydrothermal Vent Microbial Ecosystems

    • Hydrothermal vents are home to chemosynthetic bacteria, which are the basis of a unique ecosystem that thrives in total darkness.
    • In most shallow water and terrestrial ecosystems, energy comes from sunlight, but in the deep ocean there is total darkness.
    • These bacteria form the basis of the entire hydrothermal vent ecosystem.
    • The ecosystems around hydrothermal vents rely on mats chemosynthetic bacteria, and many species feed on the bacteria.
    • Hydrothermal vents are some of the most unique ecosystems in the world

  • Organization of Ecosystems

    • Although ecologists tend to regard ecosystems as basic structural units, it can be difficult (if not impossible) to formally define the boundaries of a given ecosystem.
    • As such, ecosystems are better thought of as conceptual rather than actual geographical locations.
    • These interactions may be best described by detailing feeding connections (what eats what) among biota in an ecosystem, thereby linking the ecosystem into a unified system of exchange.
    • All life forms in an ecosystem can be broadly grouped into one of two categories (called trophic levels):
    • This image shows a simplified food web model of energy and mineral nutrient movement in an ecosystem.

  • Ecosystem Dynamics

    • Ecosystems are controlled both by external and internal factors; they can be both resistant or resilient to ecosystem disturbances.
    • Ecosystems are dynamic entities controlled both by external and internal factors.
    • External factors, such as climate and the parent material that forms the soil, control the overall structure of an ecosystem and the way things work within it, but are not themselves influenced by the ecosystem.
    • Resistance is the ability of an ecosystem to remain at equilibrium despite disturbances.
    • Humans may impact the nature of an ecosystem to such a degree that the ecosystem can lose its resilience entirely.

  • Ecological Pyramids

    • Pyramids of numbers can be either upright or inverted, depending on the ecosystem.
    • Another way to visualize ecosystem structure is with pyramids of biomass.
    • Pyramid ecosystem modeling can also be used to show energy flow through the trophic levels.
    • All types of ecological pyramids are useful for characterizing ecosystem structure.
    • However, in the study of energy flow through the ecosystem, pyramids of energy are the most consistent and representative models of ecosystem structure.

  • Introduction to Ecology

    • Ecology is the study of organisms, populations, and communities as they relate to one another and interact in the ecosystems they comprise.
    • These levels are organism, population, community, and ecosystem .
    • In ecology, ecosystems are composed of dynamically-interacting parts, which include organisms, the communities they comprise, and the non-living (abiotic) components of their environment.
    • The variety of organisms, called biodiversity, which refer to the differing species, genes, and ecosystems, enhances certain ecosystem services.
    • Ecologists study within several biological levels of organization, which include organism, population, community, and ecosystem.

  • Community Ecology and Ecosystem Ecology

    • Community ecology studies interactions between different species; abiotic and biotic factors affect these on an ecosystem level.
    • Ecosystem ecology is an extension of organismal, population, and community ecology.
    • The ecosystem is composed of all the biotic components (living things) in an area along with that area's abiotic components (non-living things).
    • Ecosystem biologists ask questions about how nutrients and energy are stored, along with how they move among organisms and the surrounding atmosphere, soil, and water.
    • Researchers interested in ecosystem ecology could ask questions about the importance of limited resources and the movement of resources, such as nutrients, though the biotic and abiotic portions of the ecosystem.

  • The Phosphorus Cycle

    • Phosphorus is an essential element of living things, but, in excess, it can cause damage to ecosystems.
    • Phosphorus is often the limiting nutrient (necessary for growth) in aquatic ecosystems.
    • Phosphorus is also reciprocally exchanged between phosphate dissolved in the ocean and marine ecosystems.
    • Excess phosphorus and nitrogen that enters these ecosystems from fertilizer runoff and from sewage causes excessive growth of microorganisms and depletes the dissolved oxygen, which leads to the death of many ecosystem fauna, such as shellfish and finfish.
    • Phosphate and nitrate runoff from fertilizers also negatively affect several lake and bay ecosystems, including the Chesapeake Bay in the eastern United States, which was one of the first ecosystems to have identified dead zones.