(Notes) Environment and Ecology

Environmental Ecology is the branch of biology which studies the interactions among organisms and their environment. Objects of study include interactions of organisms with each other and with abiotic components of their environment. Let’s find out more about Environmental Ecology.

Ecology is a broad term which is also known as bio ecology, bionomics or environmental biology as it specifically studies the relationship between the organisms and the environment.

Environment is everything that surrounds us, whereas ecology is how all those work. It refers to the study of the interaction of organisms with their environment. Ecology seeks to understand life processes, adaptation and biodiversity. On the other hand, the environment aims to identify the internal and external factors that affect the population.

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Environment vs Ecology

Following are the important difference between environment and ecology:

Environment refers to the interaction between the physical, chemical and biological components.Ecology is the study of the relationship between organisms and their environment.
The environmental issues include pollution, deforestation, global warming, and other broader issues.The ecological issues include population size, diversity, distribution of organisms, and competition between them.
Studies the internal and external factors affecting the environment.Aims to understand life processes, distribution, adaptation and biodiversity.

Basics –

The totality of surrounding conditions in which organisms survives is called environment.

Environment is composed of both living and non living components.

Proper balance between biotic and a biotic factors is essentials for the survival of living organisms.

Factors of Environment –

    Biotic factors –

  • Plants – Converts a biotic factor into food for animals through photosynthesis.
  • Animals – All living organisms depend on other organisms for food and in-turn become food for other organism.

E.g. grass–>deer–>tiger–>vulture–>micro-organisms–>back to minerals deeded by grass

A biotic Factor –

Light – Essential for photosynthesis and movement

Water –Medium for biochemical reactions

Regulation of body temperature

Habitant for aquatic plants and animals

Temperature –Essential for the functioning of all environment cycles

Certain range of temperature and humidity is essential for survival of Organisms

Atmosphere –Contains life supporting gases.

    Sub-stratum –Soil, deep water vents or any surface supporting life forms.


Basics – Ecology is the scientific study of inter-relationships between organisms and their environment.

The term ecology was first coined in 1869 by the German biologist Ernest Haeckel.

Levels of ecological organisms –

  • Organisms – individual
  • Population – A group of organisms of the same species inhabiting a given area.
  • Community – A group of different but interdependent species of plants or animals living their physical environment.
  • Ecosystem – A system formed by the interaction of a community of organisms with their physical environment.
  • Biome – A major biotic community characterized by the dominant forms of plant life and the prevailing climate.
  • Biosphere – Regions of the surface and atmosphere of the Earth where living organisms survive.

Habitat –

The type of environment in which an organisms or group normally loves or occurs.

Four major habitats

  • Terrestrial
  • Freshwater
  • Estuarine
  • Ocean


Basics –

  • Ecosystem: A system formed by the interaction of a community of organism with their physical environment.
  • Ecosystem is comprised of complex interaction between its biotic (living) and biotic (non-living) components.

Factors of ecosystem –

A biotic factor

Climate factors –

  • Temperature
  • Humidity
  • Light
  • Atmospheric pressure

    Inorganic substances –

  • Water
  • Rocks
  • Gases

    Minerals – nitrogen, phosphorous, sulphur etc.

Organic substances –

  • Carbohydrates
  • Proteins
  • Lipids

  Biotic factors

  • Producers – Autotrophs
  • Plants
  • Phytoplankton
  • Phytoplankton is mainly unicellular algae
  • Spirogyra
  • Ulothrix
  • Cladophora
  • Diatoms
  • Volvox
  • Consumers – Heterotrophs
  • Zooplankton
  • Herbivores
  • Carnivores
  • Omnivores
  • Decomposers – Saprotrophs or Detrivores
  • Bacteria
  • Fungi

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