Basic Ecological Concepts

Ecology deals with how the environment influences the organisms and how the organisms influences the environment. it can be said to be the study of the relationships between organisms and their environment. This term is derived from two greek words - Oikos meaning home and Logos meaning to study. Ecology is a practical science.

There are two types of Ecology:

• Autecology:The branch of ecology that deals with the biological relationship between an individual organism or an individual species and its environment.

• Synecology: The study of the ecological interrelationships among communities.

Concepts of Ecology

The basic ideas involved in the study of Ecology are referred to as concepts of Ecology and they are as follows:

• Environment: This is the total surrounding of an organism. This is made up of two components.

  • Biotic or living components

  • Abiotic or non living components

• Biosphere: This is the portion of the earth inhabited by organisms. This includes land, ocean and air.

• Atmosphere: The layer of air surrounding the earth. It is made up of gasses.

• Lithosphere: This is the solid crust of the earth on which plants and animals live.

• Hydrosphere: This consists of the bodies of water on earth, including lakes, ponds,etc found both above ground and under ground.

• Habitat: A place which has all necessary conditions that enable it to support the life of an organism.

• Niche: A special place within a habitat where an organism lives, or the special function of an organism with respect to other organisms.

• Population: The number of a specific specie of an organism which occupy a particular area or space within a period of time.

• Community: All organism found/occupying in a particular area or space.

• Biome: A large community which has a characteristic appearance.

• Ecosystem: A self supporting unit made up of living and non living parts.

Components of an Ecosystem

There are two components of an Ecosystem which are as follows:

Abiotic: These are non-living components of the Ecosystem. They are as follows:

• Climate:

  • Rainfall: In terrestrial habitats,rainfall is the main supply of water for plants and as such has a great influence on vegetation.

    • Low rainfall leads to scarcity of water for plants and as such animal food supply becomes low leading to drought.

    • Good amount of rainfall distributed over many months encourages plant growth and more food for animals.

    • High amount of rainfall leads to water logged areas and soil erosion. Such conditions does not favour many plants.

  • Temperature

  • Relative humidity

  • Wind

  • Light

• Topographic:

  • Elevation: The higher above sea level one goes the lower the temperature and the higher the wind blows

  • Gradient of Slope:The angle or slope of the ground affects living organisms

  • Exposure: The extent to which an area is open or sheltered is known as exposure.

• Edaphic or Soil:

  • Types and Characteristics of Soil:

    • Sandy soil:

      • Retains little water and is easily drained.

      • It is well aerated and has poor capillarity.

      • Water easily sinks through it,leaching materials into ground water

      • It has low water holding capacity as well as low fertility

      • It supports only scanty vegetation

    • Loamy soil:

      • It is a fairly balanced mixture of clay, sand and silt.

      • It is well drained and has sufficient air and good crumb structure.

      • It is the most favourable conditions for plant growth and supports thick vegetation.

    • Clayey soil:

      • It has high capillarity and hence retains water.

      • It is neither well aerated nor well drained.

      • It is hard when dry and heavy and sticky when wet.

      • It has much plant nutrients and as such favours the growth of certain species.

  • pH: This is the measure of acidity or basicity/alkalinity of a solution. Some plants prefer acidic soil (e.g. Tea); other plants prefer alkaline soil (e.g. Cocoa) while most plants prefer neutral soil.

  • Other soil factors includes:

    • Soil water

    • Soil organic matter

    • Soil air

    • Soil fertility

• Ecological Factors in Aquatic Habitats

  • Salinity: concentration of salts in water

  • Speed of flow of water: whether fast flowing or slow

  • Depth of water: this affects light penetration

  • Nature of Substratum: the bottom of the river or stream or pond are usually different

  • Turbidity: this is the degree of cloudiness of water

  • Oxygen: amount of oxygen dissolved in water