Ecology, Ecosystem and Biosphere
Chapter Four
Syllabus topic 1, "The Idea of Environment"
Pages 13 to 16 of 595
In one line
Ecology is a study, an ecosystem is a working unit, the biosphere is the whole of the living world, and biodiversity is a measure of how much variety there is in it.
Why a law student needs these words
Because the judgments use them, the statutes use them, and the examiner uses them. When the Supreme Court says that a decision must not "gravely impair the ecology and environment", or that a tank is a "local ecological resource", it is using terms with definite content. A student who treats them as synonyms for "nature" will write an answer that never engages with what the court actually said.
There is a second reason. Two of these words carry definitions in a binding instrument, one in an Indian statute and one in a treaty India has ratified, and a question that asks for the idea of environment can be answered much more precisely with a defined term than with a general description.
Ecology
Ecology is the branch of biology that studies the relationships between living organisms and between organisms and their physical surroundings. The word was coined in the nineteenth century from the Greek oikos, a household, and logos, a study: the study of the household of nature.
It is a discipline, not a thing. This is the distinction most often got wrong. You cannot pollute an ecology, damage an ecology or protect an ecology, any more than you can pollute a chemistry. What you can damage is an ecosystem, or ecological balance, which is the state of equilibrium the discipline studies.
The phrase Indian judgments actually use is ecological balance, and it means the condition in which the populations of the organisms in an area, and the physical conditions they depend on, remain roughly stable over time because the processes that remove them and the processes that replace them are in step.
Ecosystem
An ecosystem is a community of living organisms together with the non-living components of their surroundings, interacting as one functional unit. A pond is an ecosystem; so is a mangrove swamp, a grassland, a coral reef and, at a stretch, a city.
The definition to quote is in article 2 of the Convention on Biological Diversity 1992: "Ecosystem" means a dynamic complex of plant, animal and micro-organism communities and their non-living environment interacting as a functional unit. The Indian Biological Diversity Act 2002, which was enacted to give effect to that Convention, does not itself define the word.
Four elements are worth pulling out of that definition.
- Dynamic. An ecosystem is not a fixed arrangement. It changes, and the law's task is not to freeze it but to keep the change within limits it can absorb.
- Complex. Many species, not one. This is why protecting a single charismatic animal is not the same as protecting the system it lives in.
- Their non-living environment. The soil, the water, the light. The system includes the physical conditions and not merely the organisms.
- Interacting as a functional unit. The relationships are the thing. Remove the pollinators and the plants fail, whatever else you have preserved.
Ecology, Ecosystem and Biosphere
Biosphere
The biosphere is the whole of the part of the earth in which life exists: the thin shell running from a few kilometres below the surface of the ocean to a few kilometres above the land, together with the atmosphere the living things exchange gases with. It is the largest unit in this vocabulary, and there is only one of it.
The word matters to a lawyer for one reason. Some environmental harms are local, and the law can deal with them by identifying a polluter and a victim: an effluent in a stream, a chimney in a street. Others operate on the biosphere as a whole, and there is no victim in any traditional sense: the ozone layer, the climate, the ocean. Those harms broke the old law of nuisance, and the whole of international environmental law is the attempt to replace it.
Biodiversity
Biological diversity, usually shortened to biodiversity, is the variability among living organisms. Section 2(b) of the Biological Diversity Act 2002 defines "biological diversity" or "biodiversity" as the variability among living organisms from all sources and the ecological complexes of which they are part, and says it includes diversity within species or between species and of eco-systems. Article 2 of the Convention says the same thing in slightly fuller words, adding "including, inter alia, terrestrial, marine and other aquatic ecosystems".
Notice the three levels in the definition, because they are what makes the idea useful.
- Within a species. The genetic variation between individuals and between local populations. It is what allows a species to survive a disease or a change in climate, and it is why a rice variety grown by one village can matter.
- Between species. How many different species there are in a place. This is what most people mean by biodiversity.
- Of ecosystems. How many different kinds of system there are. A country with one enormous forest is less diverse than one with a forest, a wetland, a grassland and a desert.
A worked example
The Thane creek, on the eastern edge of Mumbai, is fringed with mangrove. Suppose a reclamation scheme fills a hundred hectares of it for housing, with a bund replacing the tidal channel.
Work the vocabulary through the facts. The ecosystem destroyed is the mangrove: a dynamic complex of salt-tolerant trees, the crabs and molluscs in the mud, the fish that breed among the roots, the birds that eat them, and the tidal water that connects them. The ecological balance disturbed is wider than the hundred hectares, because the mangrove was the nursery for fish caught kilometres away and the buffer that took the force of a storm surge off the shore behind it. The biodiversity lost has all three components: particular local populations of mangrove species with their own genetic character, a number of species that will simply no longer occur here, and one whole ecosystem type gone from this stretch of coast. The biosphere is affected too, though not visibly: mangrove sediment is among the densest stores of carbon on earth, and filling it releases what it held.
Ecology, Ecosystem and Biosphere
Nothing in that paragraph could be said with the single word "environment". That is the point of the vocabulary.
What these words do NOT mean
Ecology is not a synonym for environment. A sentence like "the project damaged the ecology" is loose. The disciplined form is "the project damaged the ecosystem" or "disturbed the ecological balance", and judgments that use the loose form are quoting popular usage rather than defining a term.
An ecosystem is not the same as a habitat. A habitat is where a particular species lives. An ecosystem is the whole working unit, including everything else in it.
Biodiversity is not the same as the number of animals. It is a measure of variety at three levels, and a place can have a great many individuals of very few species and be poor in diversity.
Distinctions that carry marks
| Word | What it is | Can it be damaged? | Defined in Indian law? |
|---|---|---|---|
| Ecology | The scientific study of relationships between organisms and surroundings | No. The balance it studies can be | No |
| Ecosystem | A community of organisms plus their non-living surroundings, working as a unit | Yes | Not in the Indian Act. Defined in art 2, Convention on Biological Diversity 1992 |
| Biosphere | The whole zone of the earth in which life exists | Yes, and globally | No |
| Biodiversity | Variability among living organisms, within and between species and of ecosystems | Yes | Yes, s.2(b) Biological Diversity Act 2002, and art 2 of the Convention |
| Environment | The surroundings and their interrelationships | Yes | Yes, s.2(a) Environment (Protection) Act 1986 |
Quick revision
- Ecology is a discipline. What gets damaged is the ecological balance, not the ecology.
- Ecosystem, article 2 of the Convention on Biological Diversity 1992: a dynamic complex of plant, animal and micro-organism communities and their non-living environment interacting as a functional unit. The Indian Act does not define it.
- Biosphere: the whole zone of the earth in which life exists. Harms at this scale are what broke the old law of nuisance and produced international environmental law.
- Biodiversity, section 2(b) of the Biological Diversity Act 2002: variability among living organisms, at three levels, within species, between species, and of eco-systems.
- Two of the four carry defined meanings in a binding instrument, which is why they are worth quoting in an answer. Ecology and biosphere carry none, so use them descriptively.
Ecology, Ecosystem and Biosphere
Test yourself
1. Give the defined meaning of an ecosystem, say where it comes from, and identify the words in it that do the most work.
Article 2 of the Convention on Biological Diversity 1992: a dynamic complex of plant, animal and micro-organism communities and their non-living environment interacting as a functional unit. The Indian Biological Diversity Act 2002 gives effect to that Convention but does not define the word itself, so do not attribute the definition to the Act. The phrase that does the most work is "interacting as a functional unit", because it is what makes the ecosystem a system rather than a list of things in one place.
2. Why is it wrong to say that a project "damaged the ecology"?
Because ecology is the study of relationships, not the relationships themselves. What a project damages is an ecosystem, or the ecological balance of an area.
3. Name the three levels at which biodiversity is measured.
Within a species, which is genetic variation; between species, which is how many kinds there are; and of ecosystems, which is how many different kinds of system a place contains.
4. Why does the biosphere matter to a lawyer when the ecosystem is the unit that gets damaged?
Because some harms operate on the biosphere as a whole, notably ozone depletion and climate change, and those harms have no identifiable local victim. The traditional private law remedies, nuisance and negligence, cannot reach them, which is why they had to be dealt with by treaty and, more recently, by constitutional right.
The rest of this subject
These notes are cut from the University's printed syllabus. Open the syllabus itself, or the past papers, for the same subject.