Agricultural exploitation Flashcards
what is monoculture
the growth of large numbers of genetically identical crop plants in a defined area
why does the same crop is grown in the same plot reduce yield progressively
the roots are always the same length so they extract the same minerals from the same depth of soil
intensive cultivation has therefore hugely increased the use of inorganic fertilisers
the same species is always susceptible to the same pests which increase in number so more insecticides herbicides and fungicides used
why does overgrazing of cattle cause grassland to become unsustainable
hooves compact soil which dries out the air in the soil
which prevents water draining through
roots cannot penetrate the soil and so grass for grazing cannot grow
what has farming lead to
a decrease in biodiversity through
the removal of hedgerows
monoculture
overgrazing of cattle
what are the reasons for deforestation
timber is used extensively both as a building material and as fuel
provides paper and packaging
the land is also cleared for farming often to produce biofuels or grazing for cattle
what are the consequences of deforestation
soil erosion
lowland flooding
lower rainfall
habitat loss
biodiversity loss and an increase in atmospheric carbon dioxide
what is soil erosion
the removal of topsoil which contains valuable nutrients
what is coppicing
cutting down of trees close to the ground and leaving them for several years to regrow
what is selective cutting
felling only some trees leaving the other in place
what does a long roatation time mean
increases sustainability as many years are left between harveting adjacent areas of forest and a variety of habitats develop favouring diverse wildlife
what are good forestry practices
planting trees the optimum disrance apart
comtrolling pests and diseases
cutting a similar number of trees each year for long perios of time allows the forest ecosystem to be maintained
