Environmental Impacts Of Agriculture Flashcards
What sort of areas have to be cleared to produce farmland?
Natural biomes of grassland and forest
Where the climate is favourable and soil fertile
Will the land use change to farmland destroy the habitat?
Might not destroy the habitat but might change it so indigenous species cannot survive
What are some ways farmland can change an area?
Drainage
Nutrient enrichment
Reduced biodiversity
Why is farmland drained?
To produce more aerobic soils
What is an example of drainage?
Drainage of water logged grassland to increase grass growth
What might happen to the indigenous species when wetlands are drained?
Plant species and animals the they support may not be able to survive the changes
How can nutrient be enriched in an area?
Addition of fertilisers
Why are fertilisers added to fields?
Increase nutrient availability
Increase plant growth
How can nutrient enrichment of farmland change the area?
Species that respond by growing taller such as grasses may out-compete smaller plants such as wild flower species
what do natural ecosystems often have?
small scale local variations in abiotic factors producing differences in the composition of the community of species found there
what do agroecosystems do to natural ecosystems?
often replace diverse communities of indigenous species with a community of species that has fewer species many of which might not be indigenous
why might indigenous species not be able to survive an agroecosystem?
not be able to survive the new conditions or may be removed due to new predators or competitors
does agriculture just destroy habitats?
can also create new habitats which may be gradually colonised by wildlife species
what happens to some areas that have been farmed for a longtime?
have become plagioclimax habitats that are valuable to wildlife
what are some examples of habitats created by farming that support important wildlife communities?
hedgerows
hay meadows
grazed moorland or heathland
chalk grassland
what is the problems with some species introduced by agriculture?
some crop and livestock species that colonise the new area might become pests
what are some pests that have been accidentally introduced because of agriculture? (Fungus)
blight fungus of potato and tomato crops
what is biological control?
a way used to control pests instead of using pesticides which should reduce environmental damage
what is the negative of biological control?
introducing non-indigenous species species can cause problems (introduced predator might consume lots of species)
what are the main causes of pollution in agriculture?
use of agrochemicals (pesticides and fertilisers)
releases greenhouses gases
why are pesticides used?
because they are toxic and are intended to kill pests
what are the negatives of pesticides?
some not species specific so sensitive species may be killed as well
interspecies relationships may be affected
what ways can pesticides affect inter-species relationships?
death of food species
death of pollinators
pollution that favours competitor species
what can stimulate the growth of undesirable organisms?
the nutrients that were intended to stimulate crop growth, or are digestive waste from livestock
what can cause eutrophication?
leached inorganic nutrients such as nitrate fertilisers
what can cause deoxygenation of rivers and lakes?
organic nutrients such as manure because of aerobic respiration of bacteria
what is the problem with nitrates going into water bodies used as water sources?
high nitrate levels can cause blue baby syndrome
nitrates may be a human carcinogen
what agricultural processes release carbon dioxide?
fossil fuel use
ploughing increases soil aerobic respiration
how do agricultural processes release methane?
microbial anaerobic digestion
livestock intestines
rice padi fields
how do agricultural processes release oxides of nitrogen?
from livestock manure and nitrogen fertilisers
how does irrigation affect the hydrological cycle?
depletes water sources such as aquifers or rivers
how can agriculture affect soils part in the hydrological cycle?
can reduce the soils water retention and moderation of extremes in flow
how can soil compaction affect the hydrological cycle?
can increase run-off rates and cause more rapid fluctuations in river flow
what does change in evapotranspiration rates depend on?
the ecosystem that was present before farming started
where is evapotranspiration increased?
arid areas
where may evapotranspiration be reduced?
once forested areas
why is soil important?
its the growing medium in almost all agricultural systems
what can poor soil management lead to?
rate of erosion exceeding the rate of formation so amount of soil present declines
