Applied Ecology

Agroecosystems

• Formed between biotic and abiotic factors in a defined area, an agroecosystem influences the distribution and population of living organisms. They tend to minimise human impact.
• Differences from normal ecosystems:
• maintenance at an early successional rate
• monoculture
• crops planted in rows
• simplification of biodiversity
• intensive tillage
• use of GM organisms and artificially selected crops
• Refers to the study of an ecological phenomenon in the crop field e.g. the relationship between predator and prey. It needs energy input to maintain a balance e.g. use of pesticides disturbs balance by killing organisms.
• Maintenance keeps pest populations at manageable levels:
• Ecosystems are ever changing systems
• Ecosystems follow food webs
• All elements of an agroecosystem are closely linked, disturbance to one has effect on others

Conservation

• Humans recognise the necessity to maintain a balance between the needs of ourselves and other species.
• Conservation of forests: encouragement of sustainable use of forests.
• Governments must be persuaded that more money can often be made by exploiting forests on a sustainable basis than by destroying them.

Diversity

• This depends on the number of species and abundance of each species in an ecosystem.
• Growth of population depends on:
• Abiotic factors
• Biotic factors
• D is the index of diversity
• N is the total number of organisms of all species in area
• n is the total number of organisms of each species in area
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