Topic 18 - Biodiversity and Ecosystems Flashcards
What is biodiversity?
A measure of the variety of species of organisms in a given area.
Why has the human population skyrocketed in the last 200 years?
The Industrial Revolution and the continued development of technology.
What is the population of humans in 2023? (Roughly)
8 billion people.
What would normally happen if a population of a species rapidly increased?
Nature would restore the balance and the population would soon return to normal conditions.
What kind of factors would reduce the population of a species?
Predators, lack of food, build-up of waste products and diseases.
How does agriculture impact biodiversity?
Land used for farming has a monoculture, typically, and this leads to other species of plants and animals to be relocated or destroyed.
How does quarrying affect the environment?
The land used to dig up rock reduces land available for organisms to live on and destroys habitats of organisms already living there.
How does industrialisation/urbanisation affect the environment?
The creation of cities removes habitats for housing, shops and other amenities for people to use. The industrialisation of these places can have a knock-on effect where the greenhouse gases released cause climate change which further kills organisms.
How does human waste affect the environment?
Human waste pollutes the natural world by introducing unnatural chemicals and filling up land that could house organisms.
What problems have humans created in the water?
Humans have released pollutants into the water like sewage, fertiliser and by toxic chemicals released in the industry.
How can the land be affected by humans?
Toxic chemicals like fertilisers or pesticides Damage the soil and the organisms living there.
What happens when the water becomes polluted with fertiliser or sewage? What is the name of this process?
High levels of Nitrate that comes from protein from formerly biotic parts of the sewage alongside other mineral ions stimulate the rapid growth of algae which cover the deep waters from receiving light by blocking it out, meaning plants cannot carry out photosynthesis at these places, killing them due to a lack of energy and reducing biodiversity. The name of this process is eutrophication.
During eutrophication, fish die as well, why is this?
There is a big increase in microorganisms feasting on the algae, using oxygen in respiration to do this, this means that oxygen levels decrease and fish cannot use oxygen to respire and thus suffocate.
The death of fish in the water due to eutrophication leads to a feedback loop, explain why.
The death of fish means that more decomposers can survive in the water by feasting on the fish and using even more oxygen and further suffocating more fish.
When toxic chemicals are released into the water, what happens to the food chain? What is the name of this process?
The toxic chemicals build up in smaller organisms, which are consumed in bulk by larger organisms which can poison them, this is called bioaccumulation.
What is one thing that people in industrialised societies do in large number which harm the environment?
Waste, which can destroy land for habitation due to the creation of landfill. Toxic chemicals can be spread from the waste to the soil and poison it.
What knock-on effect did the 1986 Chernobyl Nuclear Meltdown have on sheep in Wales in 2012?
Radioactive isotopes release in the Chernobyl meltdown stayed in the clouds, falling as rain into the soil in Wales, these radioactive isotopes now infested the soil and poisoned the sheep and could have poisoned their meat, perhaps poisoning humans later.
How is acid rain created?
When fossil fuels are burned, sulfur impurities react with Carbon Dioxide to form Sulfur Dioxide, Nitrogen impurities doing the same, leading to acid dissolving in water, and being sent down when it rains.
What are the effects of acid rain?
Acid rain melts leaves and kills plant and animal life, leading to the erosion of biodiversity.
What is the effect of smoke pollution?
The smoke blocks out the sun’s rays which causes Global Dimming, decreasing worldwide temperatures and potentially threatening the existence of life on earth.
What are the effects of smog?
Smog causes the air to be polluted, causing visibility to decrease and causing fine particles of harmful chemicals to build up in your lungs, causing long-term health problems.
What are the three main causes of deforestation?
- To grow foods like rice or ingredients for making cheap food like palm oil.
- To rear more cattle for the beef market.
- To grow crops that can be used to make biofuel with ethanol. These include sugar cane and maize.
Describe the two ways in which carbon dioxide levels are increased by deforestation.
Firstly, trees are cut down which would have taken in CO2, reducing the amount that is taken out from the atmosphere.
Secondly, the trees are normally burned or the process to cut them involves combustion in a way, this means that CO2 is released in order to cut them down too.
Why is biodiversity decreasing due to deforestation?
As forests are cut down, many species are deprived of their habitat, destroying the food chain and all of the plant life near to the trees.
