21.4) Conservation Sustainable resource: is one that is produced as rapidly as it is removed from the environment so that it does not run out. Sustainable development: is development providing for the needs of an increasing human population without harming the...
21. Human Influences on Ecosystems
21.3) Pollution
21.3) Pollution Sources and effect of pollution of land and water. Insecticides: eg DDT controls spread of malaria by killing mosquitos which carry the protoctist parasites that cause the disease. Remains in the environment after it has been sprayed and can be...
21.2) Habitat destruction
21.2) Habitat destruction Removal of habitats: Farmland is not natural habitat but, at one times, hedgerow, hay meadows and stubble fields were important habitats for plants and animals. Intensive agriculture has destroyed many of these habitats; hedges have...
21.1) Food supply
21.1) Food supply Modern technology has resulted in increased food production: Agricultural machinery is used to clear the land, prepare the soil and plant, maintain and harvest crops to improve efficiency. Chemical fertilisers are used to provide minerals to...