human influences on ecosystems Flashcards
fertilizer
substance that contains important nutrients for plant growth, such as magnesium and nitrates
insecticides
substances that kill insectsand, in doing so, protect the crop plants from damage
herbicides
substances that kill plants by disrupting their growth in some way
monoculture
growing only one variety of crop in an area at a given time
advantages of intensive farming
- Simplicity
- Higher yields
- Reduced costs
- Larger land and machinery
disadvantages of intensive farming
- Negative impacts on the environment, such as:
- Land clearance
- Deforestation
- Reduced biodiversity
- Soil damage
- Water pollution
- Air pollution
biodiversity
diversity of living organisms in an ecosystem
habitat
place where an organism lives
Human activities that lead to the destruction of habitats:
- using more land for food crops, livestock production and housing
- the extraction of natural resources
- freshwater and marine pollution
The extraction of crude oil and natural gas destroys habitats because:
- pollution is created by fuels when they are burned
- the search for oil or gas damages natural habitats
- drilling and mining operations need wells, roads, pipelines and other facilities
Sources of water pollution:
- oil spills
- untreated sewage
- careless disposal of rubbish
- mining waste
- nitrates entering rivers from fertiliser use
- herbicides and pesticides
- heavy metal runoff (this can carry toxic metals such as mercury that pose a danger to water life and human health
Deforestation may lead to:
- reduced biodiversity
- flooding
- loss of soil
- extinction of species
- an increase in carbon dioxide in the atmosphere
Pollution meaning
the release of any substance that has an undesired, unexpected, harmful or toxic effect on the environment
Source of pollution
how and where the pollutant enters the environment
Effect of pollution
the harm that the pollutant does when it is in the environment
