(a) Define Ecosystem (b) Describe four ways in which man has interfered with the ecosystem (c) Outline three consequences of man's interference with the eco...

Answer Details

(a) Definition of ecosystem

An ecosystem is a natural unit made up of all the living organisms (plants, animals and micro-organisms) in a given area interacting with one another and with the non-living (physical) components of their environment such as soil, water, air, sunlight and temperature, functioning together through the flow of energy and the cycling of materials.

(b) Four ways in which man has interfered with the ecosystem

1. Deforestation: Man clears forests for farming, timber, settlement and fuelwood, destroying plant and animal habitats.
2. Bush burning and overgrazing: These destroy vegetation, kill soil organisms and expose the soil.
3. Pollution: Man discharges industrial waste, sewage, oil and chemicals (fertilizers, pesticides) into air, water and soil, poisoning organisms.
4. Overhunting and overfishing (and mining/urbanisation): Man kills wildlife and fish faster than they can reproduce and destroys land through mining and building.

(c) Three consequences of man's interference with the ecosystem

1. Extinction or reduction of plant and animal species and loss of biodiversity, and disruption of the food chain and natural balance.
2. Soil erosion, loss of soil fertility and desertification following the removal of vegetation cover.
3. Pollution of air, water and land, leading to disease, climate change and general degradation of the environment.