9 - Ecosystems - Human Impact & Biodiversity Flashcards
What is biodiversity?
The variety of plant and animal life in a particular habitat
How do fertilisers affect biodiversity?
- They can leach into water and cause Eutrophication: an excess of nutrients in water, which can lead to algae growth and death of many species in the water, reducing biodiversity
- This happens due to nitrates in fertilisers getting washed into rivers when it rains
How does fish farming affect biodiversity?
- FF is done by holding nets in open water
- Food is added to the nets; waste & food leaks into water, causing eutrophication
- Parasites can get out of the farm & infect wild animals
- Predators can become trapped and die
- Fish can escape nets; issues with indigenous species
How does the introduction of non-indigenous species affect biodiversity?
- N-IS don’t naturally occur in that area; indroduced intentionally or unintentionally
- NIS compete with indigenous species for resources; if they are better, IS can eventually die out
- They can bring new diseases to a habitat, killing IS
How can we conserve biodiversity?
Through reforestation and conservation schemes
What is the impact of reforestation?
- Reforestation is when trees are replanted in an area where a forest used to exist
- Reforesting helps restore the high biodiversity that was previously lost by the cutting/burning of trees
What is the impact of conservation schemes?
- CS can protect biodiversity by preventing species dying out, methods include:
- Protecting natural habitats
- Protecting species in safe areas (like zoos) outside their natural habitats
- Seed banks to store/distribute seeds of rare/endangered plants
What are some of the benefits of maintaining biodiversity?
- Protecting human food supply
- Minimal damage to food chains
- Providing future medicines (from plants)
- Cultural aspects (like the bald eagle being conserved in the US)
- Ecotourism (helps bring money into conservation areas)
- New jobs (ecotourism, conservation/reforest schemes)
What is food security?
The access to safe & healthy food with good nutrients
What are the 5 biological factors that affect food security?
- Increasing human population
- Increasing consumption of meat & fish and increasing animal farming
- Environmental changes caused by human activity
- Sustainability
- New pests and pathogens
How can increasing consumption & animal farming affect food security?
- People may increase the amount of meat/fish in their diets
- Less energy/biomass everytime you move up a trophic level, need more meat to be full
- Meat is produced less efficiently than crops, so less of it exists to feed people
- Overfishing can also damage fish populations for future use
How can environmental changes affect food security?
- Greenhouse gases trap heat in atmosphere, increasing the global temp
- Climate change can affect the growth of crops, reducing yeilds
- Soil pollution also affects crop growth
How does sustainability affect food security?
- Sustainability is meeting the needs of the current population without affecting the future
- Like fossil fuels will run out eventually, whereas biofuels are renewable alternatives
- Biofuels affect food security by taking up land needed to grow food
- High input costs of farming may also make it too expensive for some to continue farming
How do pests & pathogens affect food security?
- Can damage crops and livestock
- Negative impact on yeilds & reduced amount that can be sold as food
