1. Species
1.1. A species is a group of organisms that can interbreed and produce fertile offspring
2. Biodiversity
2.1. Biodiversity is the range of different types of species present in an Ecosystem
3. Biomes
3.1. A Biome is a geographical region of the planet that contains distinctive communities of plants and animals
3.2. 6 different kinds of Biomes: Forests, Deserts, Grassland, Tundra, Freshwater, Marine
3.3. A Biome is distinguished by its Climate, Fauna & Flora
3.3.1. Climate is the weather conditions
3.3.2. Fauna is the animals found in the biome
3.3.3. Flora is the plants found in the biome
3.4. The distribution of Biomes is determined by Non-living Factors (abiotic factors) such as, Temperature and Rainfall
4. Ecostystems
4.1. An Ecosystem is made up of many habitats and all the organisms and the non-living factors in one particular area
4.2. A Habitat is the place where an organism lives
4.3. A Community is 2 or more types of organisms living together in a habitat
4.4. A Population is all the organisms of 1 type living together in a habitat
5. Biotic Factors
5.1. A Biotic Factor is a living factor which affects population numbers
5.2. Examples of Biotic Factors: Food, Predation & Disease
5.3. Competition
5.3.1. Competition occurs when organisms require the same limited resources
5.3.2. Examples of Competition in plants: Light, Water, Space & Soil Nutrients
5.3.3. Examples of Competition in animals: Food, Habitats, A Mate, Water
5.3.4. Competition affects Biodiversity as it can result in organisms being forced to leave the ecosystem or can lead to the deaths of the organisms
5.3.5. Types of Competition
5.3.5.1. Intra-specific
5.3.5.1.1. Between 1 species
5.3.5.1.2. More intense as the organisms require exactly the same resources
5.3.5.2. Inter-specific
5.3.5.2.1. Between 2 or more species
5.4. Predation
5.4.1. When one organisms eats another
5.4.2. Predation's impact of biodiversity
5.4.2.1. High Levels- decreases Biodiversity as more organisms are eaten
5.4.2.2. Moderate Levels- maintains Biodiverity as it keeps more dominant organisms in check
5.4.2.3. Low Levels- decreases Biodiversity because more dominant organisms survive
5.5. Grazing
5.5.1. When animals feed on parts or plants
5.5.2. Example of Grazing: Cows in a field, when they are eating the grass they are grazing
5.5.3. Grazing's impact on Biodiversity
5.5.3.1. High Levels (Over Grazing)- decreases Biodiversity because more plant species are eaten
5.5.3.2. Moderate Levels- maintains Biodiversity because it allows the less dominant plants to survive
5.5.3.3. Low Levels (Under Grazing)- decreases Biodiversity because it allows better competetors to succeed
5.6. Parasitism
5.6.1. When one organism (a parasite) feeds from another organism (the host) and it causes it harm, but rarely kills it
5.6.2. The parasite rarely kills the host because killing the host would cut off their food supply
5.6.3. Examples of Parasitism: Tapeworm, Head lice & Mistletoe
6. Abiotic Factors
6.1. An Abiotic Factor is an non-living factor which affects population numbers
6.2. Examples of Abiotic Factors: Temperature, pH, Carbon Dioxide levels, Oxygen levels, Moisture, Light intensity & Pollution
6.2.1. Temperature
6.2.1.1. Can affect the number of daisies growing in a field, for example, because if the temperature is not at the optimum for the enzymes needed to carry out photosynthesis then the daisies won't be able to photosynthesise to their full potential
6.2.2. Carbon Dioxide levels
6.2.2.1. Can affect the number of daisies growing in a field, for example, because if the carbon dioxide levels decrease then the rate of photosynthesis will also decrease therefore there are going to be less daisies
6.2.3. Light intensity
6.2.3.1. Can affect the number of daisies growing in a field, for example, because if the light reduces then the rate of photosynthesis deceases therefore there are going to be less daisies
6.3. Acid Rain
6.3.1. Acid Rain is formed when fossil fuels are burned and sulphur dioxide and nitrogen dioxide are released into the air . They go into the clouds and turn the water acidic and then it rains.
6.3.2. Acid Rain's impact on Biodiversity
6.3.2.1. Decreases plant Biodiversity as the acid destroys the leaves therefore the plant can't photosynthesise properly
6.3.2.2. Decreases fish Biodiversity as it lowers the pH of freshwater which leads to the fish deaths
6.4. Global Warming
6.4.1. Global Warming is caused when fossil fuels are burned and Carbon Dioxide, Nitrous Oxide and Water Vapour are released and form a blanket around the Earth's atmosphere. These gases trap heat therefore causing Global Warming
6.4.2. Global Warming's impact on Biodiversity
6.4.2.1. The temperature of habitats increases
6.4.2.2. An increase in temperature decreases fish Biodiversity as enzyme-controlled reactions do not work properly
7. Human Influences
7.1. Exploitation is when something is used to gain a benefit
7.1.1. For example, humans cutting down trees to make paper
7.2. Examples of Over-Exploitation
7.2.1. Overfishing
7.2.1.1. For example, catching too many haddock to supply supermarkets
7.2.2. Overhunting
7.2.2.1. For example, hunting too many elephants for their tusks (which is leading to their near extinction)
7.2.3. Overgrazing
7.2.3.1. For example, cows eating too much grass
7.2.4. Habitat Destruction
7.2.4.1. For example, deforestation of the rainforests/forests
7.2.5. Introducing Foreign Species
7.2.5.1. For example, introduction of grey squirrels (they now dominate over red squirrels)
7.2.6. Pollution
7.2.6.1. For example, oil spills, factory gases, litter & dumping sewage
7.3. Pollution
7.3.1. Examples of Ecosystems which can be affected by pollution: Air, Land, Freshwater, Seawater & Coral Reefs
7.3.2. Organisms whose presence or absence gives information about the levels of pollution are called Indicator Species
7.3.2.1. For example, Usnea Cornuta are found in good quality air and Hypogymnia Physodes are found in poor quality air
7.3.2.2. For example, Mayfly Nymph are found in clean water and Rat Tailed Maggot are found in polluted water
8. Natural Disasters
8.1. Examples of Natural Disasters which can affect Biodiversity
8.1.1. Forest Fires
8.1.2. Earthquake
8.1.3. Volcanic Activity
8.1.4. Tsunamis
8.1.5. Wind (hurricanes, tornados)
9. Sampling Techniques
9.1. Scientists take samples when investigating an Ecosystem as it's impossible to count all the animals and plants and would take too long
9.2. Scientists ensure they have reliable results by taking several samples
9.2.1. As the sample area size increases, the number of samples needed must also increase
9.3. Sampling Biotic Factors
9.3.1. Quadrats
9.3.1.1. Used to count static organisms, for example: plants, lichen, seaweed & dog whelks
9.3.1.2. Quadrats should be thrown randomly into the sample area and then the organisms should be counted- should be thrown several times to increase reliability
9.3.1.3. To prevent errors you should throw the quadrat randomly, take more samples and use a key to identify the organisms
9.3.2. Pitfall Traps
9.3.2.1. Used to count small living, moving organisms, for example, insects & slugs
9.3.2.2. To prevent errors you should make sure that it is deep enough in the hole, make sure you don't leave it for too long that the organisms eat each other, and make sure holes are in the pot to prevent drowning or the organisms dying from lack of oxygen
9.3.3. Pooters
9.3.3.1. Used to count organisms found in the tree bark for example, insects & spiders
9.3.3.2. To prevent errors you should make sure there are holes in the pot so that the organisms don't die of lack of oxygen, make sure that you don't leave it for too long that the organisms eat each other, and suck up the straw with the gauze so you don't eat the insect(s)
9.3.4. Kick Sampling
9.3.4.1. Used to count organisms found in a river, for example: mayfly larve
9.3.4.2. To prevent errors you should kick the gravel on the floor of the river, point the kick net upstream and have sampling bottles ready
9.4. Sampling Abiotic Factors
9.4.1. Light intensity
9.4.1.1. Use light meters
9.4.1.2. Possible error: Shading the light sensor
9.4.1.3. Ways to minimise error: Don't lean over probe
9.4.2. Temperature
9.4.2.1. Use soil thermometer
9.4.2.2. Possible error: Not putting thermometer deep enough into the soil
9.4.2.3. Way to minimise error: Make sure it's deep enough
9.4.3. Soil pH
9.4.3.1. Use pH meter
9.4.3.2. Possible error: Left soil on the probe from previous sample
9.4.3.3. Way to minimise error: Wipe probe clean between samples
9.4.4. Soil Moisture
9.4.4.1. Use moisture meter
9.4.4.2. Possible error: Left moisture on the probe from previous sample
9.4.4.3. Way to minimise error: Wipe probe clean between samples
10. Biological Keys
10.1. Biological Keys are used to identify an organism
10.2. There are 2 different types of Biological Keys
10.2.1. Paired Statement
10.2.2. Branching Key