HUMAN IMPACT ON BIODIVERSITY Flashcards
What is monoculture?
when only one species of crop is grown in repetitivily in the same feild.
What are some of the issues with monoculture?
allows the build up of pests specific to the crop, can lead to depletion of certian minerals as it will alwasy have the same mineral requirement.
What is nutient enrishment of soils?
artificial fertiliser helping to maximise crop yeild.
What is an issue of usiong artificial fertiliser?
it reduces biodiverstiy by allowing target crop to take over other species.
What is meant by loss of hedgerow?
loss of biodiversioty through the loss of habitat and food for hedgerow species.
what are some issues related to removing hedgerows?
you are removing the wildlife corridors for animals and are reducing their movemnt, it can also lead to soil erosion as land is a lot more exposed to wind and rain.
What is a broad spectrum pesticide?
insecticides, kill other organisms aswell as the intended target , reducing biodiversity.
What are herbicides?
Kill weeds that compete with the crop reduces, plant biodiversity and animal as it reduces food souces.
What is bioaccumulation?
The build up of conccentrations in the tissues of organiams at progressively higher trophic levels.
What are some agriculturaal practices that reduce biodiversity?
monoculture, nutrient enrichment of soils, loss of hedgerow or woodland, increased use of pesticides.
What are some agricultural practices that promote biodiversity?
polyculture, increased use of organic fertiliser, hedgeroe conservation and maitenance, integrated pest management and biological control, predetor strips.
What is polyculture?
growing a range of different crops at one time or sequently in the one place
What is an advantage of polyculture?
provides a wider range of fod sources and habitats for wildlife (greater nuber of complex food webs), conserves soil fertility, reduces the build up of pests in one area.
How is using organic fertiliser promoting biodiversity?
preserves soil crumb structure, nutrients are released at a slower rate, nutrient content is more variable.
What is a disadvantage of using organic fertiliser?
it is more difficult to store and to spread.
How is hedgerow conservation and matienance promoting biodiversity?
maintaining native trees maintains species diversity, reduce flooding, hedges provide shelter to animals, prevents soil erosion, supports all levels of the food chain.
What are some advantages of biological control?
no chemical damage, targets only the pest species, resistance by the pest is unlikely, pest resurgence is unlikely, needs little additional action, saves money.
What are some limitations of biological control?
Pest isn’t fully eliminated, only works if biological control species can adapt, unnatural crop ecosystem not found in the wild can be hostile to control.
What is a predator strip?
areas around the edge of the field encouraging an increase in numbers of natural predators of the pest (aphids).
Explain what organic pollution is?
When water is polluted with organic material (sewage, slurry, silage effluent), provide a rich nutrient source for bacteria when they enter waterways, resulting in population explosion, using up most of the oxygen in the water for aerobic respiration.
Explain what eutrophication is?
gradual and long term nutrient enrichment of waterways, nitrates and phosphates come from artificial fertilizers, increasing algae growth which prevents light penetrating to lower levels then the plants die and bacteria use up oxygen for aerobic respiration so invertebrates and fish die.
What are some ways to reduce eutrophication?
testing mineral content before applying fertilizer, only applying fertilise3r prior or during growth periods, not applying fertilizer when heavy rain is forecast, not applying fertilizer close to waterways.
Describe the greenhouse effect?
carbon dioxide and other greenhouse gases form a layer in the atmosphere trapping heat, some of the long wave radiation that’s emitted form earth is trapped by the greenhouse layer, reflected back and retained in the atmosphere resulting in atmospheric temperature rising.
