food security

• what is food security?

  having enough food to feed population
• why does birth rate affect food security?

  birth rate increase mean amount of food have to increase
• why does diet changing affect food security?

  diets changing mean demand for types of foods to be imported from developing countries because cannot grow in UK. make scarce food more scarce in developing countries.
• why do pests and pathogens affect food security?

  eat crops and damage plants. reduce food crops available
• what does environmental change do to food security?

  if rainfall decreases crops not able be grown. reduce crop yield. famine
• why does farming affect food security?

  modern farming very expensive e.g. when use fertilisers. when population increase resources become more expensive. people not able maintain food production
• why do war and conflicts affect food security?

  farming disrupted. no imports of food. threaten reliability of water
• why does overfishing decrease food stocks?

  less fish to eat. oceans of food chains affected species of fish disappear
• what is the solution to stop overfishing?

  maintain fish stocks at level where fish are bread. sustainable food production
• what do fishing quotas do?

  limit on fish that can be caught in certain areas. prevent overfishing
• what affect does decreasing net size have on overfishing of fish?

  reduce mesh size. reduce amount of unwanted or discarded fish. younger fish able read breeding age
• how does limiting movement make food production more efficient?

  by limiting movement of livestock in controlled environment it reduces energy transfer from livestock to environment. able use energy to control body temp and growth. more food produced from same input
• what is factory farming?

  calves and chickens raised in small pens. fish factory farmed in cages where movement restricted. animals fed with high protein which increases growth. less biomass wasted to surroundings and for movement
• why is factory faring controversial?

  kept close together mean disease spread. disease mean animals are unnatural and uncomfortable
• problems with free range chickens

  biomass used for respiration to provide energy for movement. outdoors so energy used to keep body temperature constant. less biomass available for chickens grow and produce eggs
• advantages and disadvantages of factory farming

  advantages : less biomass wasted in respiration for movement restricted and in temperature controlled shed. high protein diet mean control food able give food with all nutrients animal need less food wasted. eggs easily harvested. disadvantages : close together infection disease spread easier. given antibiotics which increase risk of antibiotic resistant bacteria. more crowded mean more likely fight
• what does engaging in natural behaviour do?

  increase animal welfare e.g. by reduce stress