Chapter 11 - Environmental Impacts Of Agriculture

Question 1

How does drainage impact a habitat

Answer 1

• farmlands often drained to produce more aerobic soils
• wetland plant species and the anima,s they support ,au mot he angle to survive the changes

Question 2

How does reduced biodiversity impact a habitat

Answer 2

• natural ecosystems have small scale local variations in abiotic factors producing differences in hen composition of the communities of species found there
• agroecosytems often replace diverse communities of indigenous species with a community of species that has fewer species, many of which may not be indigenous
• many indigenous species will not be able to survive the new conditions or may be removed because they are predators or competitors

Question 3

How does soil erosion impact a habitat

Answer 3

• soil is the growing medium in almost all agricultural systems
• soil erosion is a natural process but poor soil management can lead to the rate of erosion exceeding the rate of formation, so the amount of soil present declines

Question 4

How do pesticides cause pollution ( which impacts habitats)

Answer 4

• pesticides are deliberately used because they are toxic and are intended to kill pests
• because pesticides are not species-specific, sensitive non target species may also be killed.
• species may also be affected if inter relationships are affected such as the death of food species, pollinators, or pollution that favours competitor species

Question 5

How do nutrients cause pollution ( which impacts habitats)

Answer 5

• the nutrients that were intended to stimulate crop growth, or are digestive wastes from livestock, can stimulate the growth of undesirable organisms
• leached inorganic nutrients cause eutrophication
• organic nutrients such as manure can cause deoxygenation of rivers and lakes because of the aerobic respiration of bacteria

Question 6

Describe how agriculture causes changes in the hydrological cycle

Answer 6

• irrigation water can deplete the sources of the water, such as aquifers or rivers
• agriculture changes evapotranspiration rates but the actual change depends on the ecosystem that was present before farming started. Rates can be reduced in areas where forests were removed