How humans reduce biodiversity

what is biodiversity

the variety of different species within an ecosystem

why is biodiversity important

1. keeps ecosystems stable, so if one species goes extinct there will be many other food sources because there are so many other relationships that the species can rely on

2. many species provide specific services such as pollination

3. more than half of medical drugs are derived from living organisms in some way

4. we rely on photosynthetic organisms to produce oxygen

what are three ways pollution can occur

- in water from sewage, fertiliser or toxic chemicals

- in air from smoke and acidic gases

- on land from landfill and toxic chemicals

what is eutrophication

a process that occurs when a body of water becomes enriched with nutrients, leading to excessive plant and algae growth

how does run off from sewage and fertiliser affect aquatic life explain using eutrophication

Excessive nutrients (nitrates) from fertilisers are flushed from the land into rivers by rainwater. this reduces concentration of oxygen in the river

Oxygen levels reach such a low point that fish and other organisms suffocate.

These nutrients cause increased aquatic plant growth of algae and other plants.

Algae blooms prevent sunlight reaching other plants. The plants begin to die.

Dead plants are decomposed by bacteria, which use up the oxygen in the water during respiration so fish die

sewage introduces organic matter like waste from humans which is decomposed by bacteria which use up the oxygen in the water for this to due to carrying out aerobic respiration

why has waste increased

because our population has rapidly increased meaning that ther’s more waste as we need to use more and more raw materials to satisfy the needs of a growing population

how have human reduced biodiversity

- burning of fossil fuels can cause acid rain and global warming which kills plant life

- to get raw materials we have to clear out natural ecosystems for space often involving deforestation

- producing waste creating landfills filled with toxic chemicals

what are reaons for deforestation

- clearing land for farming and housing

- to grow plants we can use to make biofuels

- clearing land for extracting natural resources and mining

- logging to get wood

what are the issues with deforestation

- less trees means less photosynthesis so less CO₂ removed from the atmosphere

- loss of habitat so reduced biodiversity

- most forests are cleared by burning them which releases all the CO₂ the plant contained increasing global warming

- more flooding as there are less trees to intercept the rainfall

what are peat bogs

areas of land where the soil is both acidic and waterlogged

how does peat form

1. the microorganisms that normally help to decay plants here can’t survive as it’s too acidic and the waterlogged soil stops air and therefore oxygen from getting into the soil so not enough oxygen for aerobic respiration

2. so the plants begin to rot as they cannot survive and the partially rotted plants build up and form a substance called peat

3. this means that the carbon stored in the plant’s lifetime is stored instead of released so peat is really good as it helps to reduce global warming

why is the destruction of peat bogs bad

- they are burned as fuel or drained which releases the CO₂ stored in the peat therefore contributing to global warming

- The available peat bog habitat area for many species of animals, plants and microorganism is decreasing, reducing biodiversity

- Peat bogs are being destroyed faster than they can form – they are being used unsustainably

why are peat bogs drained

- so that area can be used as farmland

- to burn the peat for fuel

- used as compost

what are some effects of global warming

- loss of habitat as areas get flooded

- tropical diseases may become more common in other regions such as europe

- increase in pests leading to low crop yields so more famines

- melting of the polar ice caps causing rising sea levels

- many more species to become extinct if they can’t adapt to the new climate

- weather patterns will change making farming harder

remember which gas is which : ______ and _____ causes global warming whereas ____ and _____ causes acid rain

carbon dioxide and methane cause global warming

sulfur dioxide and nitrogen oxides cause acid rain

describe the greenhouse effect

short infrared radiation from the sun reaches the earth and warms it up, some is absorbed but most of it is radiated back out to space

gases such as carbon dioxide and methane absorb some of the heat energy and re emit it in all directions keeping heat energy in the earth’s atmosphere for longer and as a result the earth is kept warm and ideal for life

because carbon dioxide and methane act like a greenhouse around the earth they’re known as greenhouse gases

the way they keep the earth’s atmopshere warm is known as the greenhouse effect