Ecology
The science of how living things relate to their surroundings, and why environmental law depends on it
Scope: Ecology as a science. The legal definition of environment is covered in the note on the meaning and definition of environment.
In one minute
Ecology is the scientific study of how living things relate to each other and to their surroundings. It is a science, not a statute.
Environmental law uses ecological facts to decide whether an activity will cause harm. Exams ask for the meaning of ecology, its parts and how it differs from environment.
Exam focus
- Frequency: Frequently asked
- Usually asked as: Both (long answer and short answer)
Legal provision
No Indian statute defines ecology. The idea enters the law in two ways.
- Section 2(a), Environment (Protection) Act, 1986: environment includes the "inter-relationship" among water, air, land and living beings. This is the relationship ecology studies.
- Environmental impact assessment: a study of how a project will affect its surroundings, which relies on ecological data.
Meaning and definition
Ecology is the scientific study of the relationships between living organisms and their physical surroundings. It looks at how organisms depend on each other and how energy and materials move among them.
The German biologist Ernst Haeckel coined the term in 1866. It joins two Greek words: oikos, meaning house or habitat, and logos, meaning study. The first part of the word shows the idea: living things share one house.
- Level 1Organism: one living being.
- Level 2Population: organisms of one species in an area.
- Level 3Community: all populations of different species in an area.
- Level 4Ecosystem: a community together with its non-living surroundings.
- Level 5Biosphere: all ecosystems of the Earth.
Detailed explanation
Step 1: the two kinds of factors
Ecologists divide the surroundings into biotic factors (living things: plants, animals and micro-organisms) and abiotic factors (non-living things: sunlight, water, air, soil and temperature). Life depends on both.
Example. In a village tank near Karimnagar, fish, algae and insects are biotic. The sunlight, the water and its oxygen are abiotic. If a factory raises the water temperature, abiotic change harms the biotic life.
Step 2: interdependence
Organisms depend on one another for food, shelter and reproduction. Removing one species can affect many others, because ecology treats the whole group as a web.
Example. If poison kills the frogs around a paddy field, the insects they eat multiply. The insects then damage the crop. A harm to one species has reached the farmer.
Step 3: why law needs ecology
A court or a Pollution Control Board must decide whether an activity will cause harm. That decision rests on ecological facts, such as how much waste a river can absorb or how a forest supports its wildlife. Ecology supplies those facts. The law then turns them into limits, permissions and penalties.
Example. Before a port is built on a coast, an expert report records the mangroves, fish and birds of the area. The authority uses that ecological record to set conditions or to refuse approval.
Step 4: ecology and balance
Ecology also explains why an ecosystem can recover from small shocks but not from large ones. Small damage is absorbed. Heavy pollution can push a system past the point where it repairs itself.
Don't confuse: ecology and environment
| Point | Ecology | Environment |
|---|---|---|
| Nature | A science that studies relationships | The surroundings themselves |
| Legal status | Not defined in any Indian Act | Defined in section 2(a) of the 1986 Act |
| Question it answers | How do these living things depend on their surroundings? | What is being protected by the law? |
Inside the concept. A scientist records how the bird count in a wetland near Hyderabad changes with the water level. That is ecology.
Just outside it. A Pollution Control Board fines a factory for polluting the same wetland. The wetland is the environment, and the fine is an act of law, not of ecology.
Common mistakes
- Writing that ecology and environment mean the same. One is a science, the other is the subject of protection.
- Saying the 1986 Act defines ecology. It does not.
- Giving the wrong founder. The term was coined by Ernst Haeckel in 1866.
Leading case laws
No Indian case turns on the meaning of ecology. Courts use ecological facts in cases on pollution, forests and wildlife, which are covered in the notes on those topics.
How to write this answer in the exam
5-mark answer
- Meaning and origin: Haeckel, 1866, oikos and logos.
- Biotic and abiotic factors.
- Levels of organisation.
- Role in environmental law.
10-mark answer
- Definition and origin of the word.
- Biotic and abiotic factors, with an example.
- Interdependence of organisms.
- The five levels, from organism to biosphere.
- Why law needs ecology (impact assessment, limits on pollution).
- Difference from environment.
Key points to remember
- Ecology: scientific study of organisms and their surroundings.
- Coined by Ernst Haeckel in 1866 from oikos and logos.
- Biotic factors are living; abiotic factors are non-living.
- Levels: organism, population, community, ecosystem, biosphere.
- No Indian Act defines ecology; section 2(a) of the 1986 Act covers the inter-relationship.
Quick self-test
1. Who coined the word ecology, and in which year?
Ernst Haeckel, in 1866.
2. Name two abiotic factors.
Any two of sunlight, water, air, soil and temperature.
3. Is ecology defined in the Environment (Protection) Act, 1986?
No. The Act defines environment in section 2(a) but does not define ecology.