environmental impacts of agriculture

Question 1

list the environmental impacts of agriculture

Answer 1

1) habitat impacts
2) introduced species
3) pollution
4) changes in the hydrological cycle
5) soil erosion

Question 2

outline how habitats have been impacted by agriculture

Answer 2

1) large areas of land have been cleared= loss of habitats such as hedgerows for use of large machinery
2) drainage- producing more aerobic soils decreasing wetland habitats pushing species out a range of tolerance
3) nutrient enrichment- use of fertilisers increases the availability of nutrients and plant growth rates, species grow taller outcompeting shorter species such as wildflowers

Question 3

outline the impact of introduced species on agriculture

Answer 3

1) introduced pests- farming has introduced many new species into areas they would not naturally be, some are crop and livestock species and others become pests. other pests have been introduced accidentally
2) biological control species- introduced non-native species can cause issues such as introduced predators may eat other species as well as the pests

Question 4

outline the impact of pesticide pollution

Answer 4

1) pesticides are used on purpose as they are toxic and intended to kill pests
2) many are non-specific therefore kill non-target species
3) this can impact inter-species relationships such as predator-prey relationships

Question 5

outline the impact of nutrient pollution

Answer 5

1) nutrients intended to stimulate plant growth can stimulate the growth of unwanted organisms
2) leached inorganic nutrients can cause eutrophication causing deoxygenated water bodies

Question 6

outline nitrate toxicity

Answer 6

nitrates leached from farmland into water bodies used for potable water
high nitrate levels can cause a blue baby syndrome
nitrates are also a human carcinogen

Question 7

how does agriculture affect the hydrological cycle

Answer 7

• irrigation water can deplete sources of water such as aquifers or rivers
• soil compaction increases runoff rates causing rapid differences in river flow
• changes in evapotranspiration rates, may increase in areas which where dry before or decrease in wetter areas