Biodiversity and Human Interaction with Ecosystems

What is the carbon cycle?

The transfer of carbon between living organisms and the atmosphere

diagram for carbon cycle

Name some carbon compounds found in plants

Glucose, sucrose, fructose, starch, amino acids, cellulose

What is the water cycle

the transfer of water between living creatures and the environment

What is evaporation

Heat from the sun causes liquid water to change into water vapour

What is transpiration

Evaporation of water from the surface of leaves

What is condensation

Water vapour in the air changes back into liquid water

What is precipitation

Liquid water falls to earth as rain or snow etc

What is respiration

Release of energy from food, leading to the loss of water from plants and animals

biogas generator diagram

What us put in a biogas generator

Waste material such as plant and animal waste

What is the main constituent of biogas

Methane

What is biogas used for

Burned as fuel

Why is the generator kept sealed

To maintain pressure and prevent oxygen entering

Why is the biogas plant built underground

So gas cant escape and the container is better insulated. Safer in case it explodes

Give advantages of biogas

• Renewable and sustainable

• carbon neutral

• can use waste products

• fewer particles released when burnt

• fertilisers also produced

• can provide fuel in remote areas where there is no mains or electricity

Give disadvantages of biogas

• Pesticides may be used when growing crops

• crops grown for biogas take up space for food crops

• Hydrogen sulphide smells

• can be explosive if it goes wrong

Define biodiversity

The variety of different species of organisms on Earth, or within an ecosystem

What does high biodiversity result in

Increased stability of the ecosystem and more interdependence

Why are humans using more and more resources and producing more and more waste

Growing population

Higher standards of living

Gives three main points for water pollution

• Chemicals from industry e.g. oil spills

• chemicals used in farming washing into water

• sewage

Give three main points for land pollution

• Chemicals used in farming (bioaccumulation)

• landfill

• nuclear waste

Give two main points for air pollution

• Global warming

• acid rain

Briefly explain the effects of oil spills

They can spread easily and seep deep into the ground. They are very dangerous for plants and animals and damage the ecosystem from the base up

Explain step by step Eutrophication by fertilisers

1. Fertiliser from the fields is washed into rivers and lakes by the rain

2. algal bloom occurs due to excess nutrients

3. some plants die due to overcrowding and lack of light

4. oxygen levels fall due to less photosynthesis

5. bacteria and fungi feed on dead plants, using oxygen

6. bacteria and fungi multiply rapidly

7. oxygen levels decrease further

8. fish and animals die due to too little oxygen

Explain step by step Eutrophication by sewage

1. Untreated sewage washed/dumped into waterways

2. The high levels of nitrates in the sewage cause rapid plant growth

3. some die due to overcrowding and competition for light

4. bacteria in the sewage decay and digest the dead plants using enzymes

5. This uses up a lot of oxygen from the water

6. concentration of oxygen falls

7. fish cant carry out respiration as much so have less energy and die

Explain bioaccumulation

The build up of substances that cant be broken down, from each trophic level to the next as one animal will eat more than one of the trophic level beneath it. Not excreted. Persistent

Explain landfill

Toxic chemicals leak from landfill onto the land and into water. Methane is produced. Plastics may not decay.

Explain buried nuclear waste

Releasing radioactivity. Materials may not decompose

Explain acid rain

Sulphur oxides and nitrogen oxides in the air are caught in clouds and dissolves in rain. Acidic once dissolved. Sulphur is released by factories due to combustion

Effects of acid rain

It can erode certain types of rock such as limestone. Can affect the food chain. Kills coniferous trees. Acidification of soil and lakes

What is a common indicator species for air pollution

Lichen - different types are more or less resilient to pollution

Explain methane as a greenhouse gas

Produced when microbes break down larger organic molecules to release energy.

Possible sources include :

• decomposition of waste in landfill

• fermentation by microbes in the rumen of cows

• fermentation by bacteria in rice paddy fields

Explain carbon dioxide as a greenhouse gas

Burning fossil fuels

cement production

deforestation

Explain Nitrous Oxide as a greenhouse gas

Use of fertilizers can lead to an increase in atmospheric levels as well as the production of nylon, and the burning of fossil fuels in internal combustion engines

Explain Chlorofluorocarbons (CFCs) as a greenhouse gas

Once used in the production of fire extinguishers and fridges

Now phased out due to contribution to global warming and effects on the ozone layer

Explain water vapour as a greenhouse gas

Accounts for the largest percentage of the greenhouse effect, between 36-85%. Global warming means the air can hold more water so the amount in the air increases the greenhouse effect

What are some effects of global warming

Loss of low lying habitats due to rising sea levels

Changes in migration patterns as animals may change location to preferable condition or they may migrate earlier / later or not at all

Changes in organism distribution as animals may not be able to survive in new conditions or may migrate away. Some animals become more or less widely distributed

Give 4 ways that humans reduce the available land for other organisms

Building, quarrying, farming, dumping waste

What 3 types of fsrming is land taken up by

Food crops

Animals

Biofuel crops

What are some effects of deforestation

Loss of biodiversity

Soil infertility

Leaching of mineral ions from the soil

Flooding as trees don’t intercept or take in water anymore

Why don’t plants in peat bogs fully decompose

Lack of oxygen and low ph

What is peat

The store of carbon of partially rotted plants

What is peat used for

Dried up and burned as fuel releasing all the stored carbon

It is also sold to gardeners as fertiliser. The peat is broken down my microorganisms

How else are humans damaging peat bogs

Often have drainage ditches dug into them so that the area can be used as farm land. This increases oxygen levels and destroys the habitat leading to a loss of biodiversity

What 4 types of conflict arrise due to methods to maintain biodiversity

Economic - paying farmers subsidies to reintroduce hedgerows

Social - fishing quotas to reduce overfishing may lead to a loss of livelihood for fishermen

Food security - killing pests that eat our food may reduce biodiversity of an area

Development - use of greenfield sites to build houses

Define food security

Having enough food to feed a population

What biological factors affect food security

Higher birth rate

Changing diets - higher demand for some foods

Farming is affected by changes in environmental conditions or new pathogens / pests

High input costs of farming make it hard to maintain

World conflicts may affect availability of food and water

What 3 ways can the efficiency of pastoral farming be increased

Limiting movement of animals to prevent energy waste. More energy used for growth

Controlling temperature so no energy wasted on keeping warm or cooling down

Feed high protein diet to aid growth

Give three advantages of intensive farming

Higher productivity and output to feed population

Cheaper

Better standard of living for farmers

Give 3 disadvantages of intensive farming

Animal cruelty

Crowded conditions = spread of disease

Lots of energy needed to maintain temperature. Expensive . Burning fossil fuels

Why are fish stocks declining

Waste being dumped into rivers and sea. Overfishing causes depletion of fish. Accidentally catching wrong species (wasted fish)

What long term impacts could this have

Impact on food chain due to loss of interdependence. Lack of food for humans

How can fish stocks be conserved

Limiting the number of fish a boat can catch. Restricting areas where fishing is allowed. E.g. no breeding grounds. Control net sizes

What is Mycoprotein and how is it made

Made from the fungus Fusarium

Used to make high protein substitutes e.g. Quorn

Grown in large vats on glucose syrup which acts as food for the fungus

Fungus is supplied with oxygen, ammonia, and minerals at a constant pH and temperature

Fungal biomass is then harvested, purified, and dried

Mycoprotein diagram

What environmental changes can impact the ecosystem

Temperature

Availability of water

Composition of atmospheric gases

Etc

What 2 categories can environmental changesbe put in

Seasonal and geographical

Give 4 negative environmental effects caused by humans

Global warming

Climate change

Acidificstiom of lakes and soil

Pollution - eutrophication and bioaccumulation etc

Give 4 positive environmental changes caused by humans

Maintaining rainforest

Reducing water pollution

Restricting access to sites of scientific interest

Conservation