Human Impacts - Food Security Flashcards
Food security is influenced by a number of factors
- Food production
- Human population
- Socio-economic
- Political
Human population growth in South Africa between 2001 and 2011.
40-50 million
Examples of specific socio-economic factors leading to food insecurity in households
- Household size (overpopulation)
- Food prices
- Fuel prices
- Unemployment
- Exchange rates
Effects of food insecurity
- Hunger
- Malnutrition
- Child health
Negative factors for food production
- Climate change
- Poor farming practices
- Exotic plant species
- Poor crop gene pools
- Wastage
Climate events exacerbated (made worse) by climate change leading to food insecurity
- Drought
- Floods
- Intense weather events e.g. hail
Monoculture
- Modern farming techniques
- Large areas planted with one crop
- Commercial farms
Advantages of monoculture
- Low labour
- High yields
Risk of monoculture
Vulnerable to pests
Pest control used typically by commercial farmers
Synthetic pesticides
Possible effects of pesticides
- Kill pests
- Leach into waterways
- Kill natural predators of pests
- More pesticides needed
- Crops can fail
Alternatives to pesticides
- Avoid monoculture
- Use natural pesticides
- Encourage natural predators
- Plant companion crops
- “Organic farming”
Farming practice leading to most intense soil erosion
Grazing livestock
Two types of soil erosion resulting in loss of topsoil
- Sheet erosion
- Gully formation
Main method crop yields increased by commercial farmers
Synthetic fertilisers
Main chemical ingredients in fertilisers
- Nitrates
- Phosphates
Alternatives to using excessive fertilizers by farmers
- Crop rotation
- Composts
- Avoiding monoculture
Wild ancestral animal or plant stock improved through selective breeding
Domestication
Improvements to farm stocks through domestication
- Yield increased
- Nutritional value
- Accelerate growth
- Able to survive variable climates
- More resistant to disease
Process allowing for domestication of farm stocks
- Selective breeding
- Inbreeding
Dangers of inbreeding
- Reduced variety of genes
- Susceptibility to diseases
- Species ultimately weakened
Solution to problem of inbreeding and poor gene pool of farm stock
- Outbreeding
- Breed with wild varieties
Solutions to loss of wild varieties of food stocks
- Protect habitats of wild varieties
- Sperm and egg banks for animals
- Seed banks for plants
Manipulating DNA to produce plants and animals with specific desirable characteristics
Genetic engineering
Reasons for genetic engineering plant stocks
- Robust forms
- Greater yields
- Larger fruits
- Withstand diseases and pests
- Need less water
Reasons for genetically engineering animal food stocks
- Greater yields
- Improved nutritional value
- Resistant to disease
List at least 5 possible problems with genetically modified stocks
- Unknown risks (potential allergies)
- New seed purchased every year
- Exploit developing countries
- Monoculture often required
- Increased use of fertilizers and irrigation
- Expensive
- Accidental transfer to other species and loss of biodiversity
- Violation of natural gene composition
Production stage food wastage
- Lower-income food wastage
- Developing countries
Food that is not eaten or thrown away
- Called food wastage
- Up to 1/3 of total world food produced
Consumption stage food wastage
- Higher- income groups
- Developed countries
