Theory question 208
The Ecosystem(a) Define Ecosystem. (b) Describe four ways in which man has interferred with the ecosystem. (c) Outline three consequences of man's interference with the ecosystem.
Show the model answer
(a) An ecosystem is a community of living things (plants, animals, micro-organisms) interacting with one another and with their non-living environment (air, water, soil, climate).
(b) Deforestation for farming, lumbering and building; bush burning; overgrazing and intensive farming with chemicals; hunting and over-fishing; mining and quarrying; industrialisation and urbanisation; dams and land reclamation; pollution of air and water.
(c) Soil erosion and loss of fertility; destruction of habitats and extinction of species; desertification; pollution and damage to health; flooding; change of local climate (global warming, ozone depletion); reduced crop yield.
Show how each human action upsets the balance between living and non-living parts.