Science of Biosphere & Ecological Organisation

Science of Biosphere & Ecological Organisation

Ecology: Concepts & Facts

Origin and Meaning of Ecology

• The term ecology is the combination of two Greek words, oikos (= 'house/habitat/dwelling place) and logos (= the study/science of).

• Thus, Ecology is the study/science of the biosphere (the dwelling place of organisms)

Definition of Ecology

• Ecology is defined as the study of the relationships of organisms to one another and to their physical environment.

• Ecology is also called bioecology, bionomics, or environmental biology.

Who Coined the Term ‘Ecology’?

There is some controversy about the person who coined the term 'ecology.'

Some scholars think that it was H. Reiter who introduced the term 'Oekologie' (ecology) in 1868, but most of the scholars think that it was German scientist Ernst Hackel (1834–1919) who coined the term 'Oekologie' (ecology) and put the first precise definition and explanation in the year 1869.

Definition by Ernst Haeckel

American biologist E.P. Odum (1913–2002) wrote in his popular textbook 'Fundamentals of Ecology':

"The word 'oekologie' was first proposed by Ernst Haeckel in 1869."

Haeckel defined ecology as:

"the study of the natural environment, including the relations of organisms to one another and to their surroundings."

Fathers of Ecology

• Ernst Hackel (1834–1919) is known as the father of ecology (classical period).

• According to some scholars, German naturalist Alexander Von Humboldt (1769–1859) is the father of ecology (classical period).

• E.P. Odum (1913–2002) is known as the father of modern ecology (modern period).

• Ramdeo Misra (1908–98) is revered as the father of Indian ecology.

Note: In science, the period from the beginning to the 19th century (i.e., the beginning century) is considered the 'Classical Period', and the period from 1901 to the present is the 'Modern Period'.

Evolution of Ecology

• Like other fields of learning, the development in the field of ecology has been gradual.

• Ecology has progressed from natural history and biogeography to ecosystem ecology.

• In the last quarter of the 20th century (1975–2000), global ecology, with an emphasis on biodiversity, climate change, and ecological sustainability, emerged.

• Global ecology is a subfield of ecology, and it treats ecology at a global scale.

Levels of Ecological Organisation (Ecological Hierarchy)

Overview

Levels of ecological organization, or ecological hierarchy, provide a convenient but holistic approach to understanding ecology, which is very complex in nature.

• In ecology, levels of ecological/biospherical organization range from organism to ecosphere/biosphere.

• It is also called Ecological/Biospherical Hierarchy (hierarchy means an arrangement into a graded series).

• Seven transcending processes or functions are depicted as vertical components in descending order.

Levels of Ecological Organisation

1. Organism

The organism is the basic and smallest unit to study in ecology.

• Organism means any individual living being/thing, whether plant or animal.

• Thus, any living structure (plant, animal, bacterium, or fungus) capable of growth and reproduction is called an organism.

(Note: Viruses are not included in constituent parts of organisms because they are incapable of autonomous metabolism, growth, or reproduction.)

2. Population

• The term population, originally coined to denote a group of people, is broadened to include groups of individuals of any kind of organism.

• Hence, a population is a group of individuals of a plant or animal species inhabiting a given area.

For example: all individuals of roses in an area, all individuals of elephants in an area, etc.

3. Community

• The term community is a combination of the French word 'commune' (a group of people) and the noun suffix "-ity" (= state, condition).

• Community (sometimes designated as biotic community) is an assemblage of all the populations occupying a given area.

For example: all the population of roses in an area, all the population of elephants in an area, etc.

4. Ecosystem

Ecosystem is the acronym of ecological system.

• The system means a set of things that work together.

• The biological community and the physical environment function together as an ecological system, or ecosystem.

• It is a fundamental functional unit of ecology because it includes both biotic (living) and abiotic (non-living) environments.

• Ecosystem is not only a middle level but also a very important level of ecological hierarchy.

For example: Forest, grassland, desert, marine, lake, river, pond, crop field, park, spacecraft, swimming pool, well, aquarium, etc.

So the structure and functioning of the ecosystem shall be discussed in detail in 'Biosphere: A Giant Ecosystem.'

5. Landscape

• The term landscape, originally referring to a painting, and explained as "an expanse of scenery seen by the eye as one view."

• In ecology, a landscape is defined as a heterogeneous area composed of a cluster of interacting ecosystems that are repeated similarly throughout.

For example: a watershed, etc.

6. Biome

The term biome is a combination of the Greek word bios (life) and the noun suffix "-(o)ma" (mass, growth).

A biome is a large regional unit characterized by a major vegetation type and associated fauna found in a specific climate zone.

For example:

(a) Terrestrial (land-related) Biomes —

• Equatorial (0°–15°) evergreen forest biome,

• Tropical (12°–25°) rainforest biome,

• Temperate (45°–66.5°) deciduous forest biome, etc.

(b) Aquatic (water-related) Biomes —

• Marine (salty-water) biomes like oceans, seas, etc.

• Freshwater biomes:

  • Lentic (standing water): lakes and ponds

  • Lotic (running water): rivers and streams

Wetlands: marshes and swamp forests (like mangrove forests).

7. Ecosphere/Biosphere

• The largest and most nearly self-sufficient ecological/biological system is designated as the ecosphere/biosphere.

• The ecosphere/biosphere includes all the living organisms interacting with the physical environment as a whole to maintain a self-adjusting, loosely controlled, pulsating state.

Note: A simple formula to remember levels of ecological organization (ecological hierarchy):

• Only Prayer Can Enable Life to Be Beautiful, Blissful

  • Only - Organism

  • Prayer - Population

  • Can - Community

  • Enable - Ecosystem

  • Life - Landscape

  • Beautiful - Blome

  • Blissful - Biosphere / Ecosphere

Final Thoughts

Ecology provides a comprehensive understanding of the relationships between organisms and their environment, from the smallest unit, the organism, to the largest, the ecosphere or biosphere. By exploring the seven levels of ecological organisation, we gain a clearer picture of how life is structured and interconnected across scales.

The distinction between biological and ecological hierarchies is crucial—cells may be fundamental in biology, but organisms are the starting point in ecology.

Knowing the origin of the term ecology, credited to Ernst Haeckel, and the evolution of its meaning over time helps us appreciate its growing relevance in today’s world, especially through fields like global ecology. It's essential to recognize the functional unity of ecosystems, where biotic and abiotic elements work in tandem.

Finally, remembering that biosphere and ecosphere are synonymous, encompassing both living and non-living environments, reinforces the holistic nature of ecological study. Keeping these specific meanings in mind is vital for deeper insight and accurate understanding in ecological discussions and examinations.