Ecology

• Population: All of the organisms of one species living in a habitat
• Community: The populations of different species living in a habitat
• Ecosystem: A community plus its physical environment, including abiotic factors such as temperature and light levels.
• Biome: An area with similar climatic conditions, containing many distinct habitats and communities.
• Abiotic Factors: Non-living components that affect an ecosystem, e.g., water, sunlight, soil type, climate, pollution.
• A change in any environment can have a knock-on effect
• All ecosystems are inter-dependant on each other
• Biotic Factors: Living things that can affect an organism's ability to survive and reproduce.
• Adaptations allow organisms to survive
• Structural adaptations affect the body structure of an animal such as fur colour, blubber layers in cold environments and large surface area to volume ratios in hot areas
• Behavioural adaptations affect how an organism behaves to stimuli such as migration
• Functional adaptations are things inside an organism that can be related to processes such as metabolism and reproduction such as producing little sweat or slowing down metabolisms during hibernation
• Food Chains show what is eaten in an environment
• Food Chains always start with a producer
• Producers are usually green plants and algae that are then eaten by a primary consumer
• Energy is transferred through the food chain when organisms are eaten
• Populations of prey and predators go in cycles, with the population of one species increasing and the other decreasing
• Environmental changes affect the distribution of organisms
• Environmental changes can include availability of water, temperature changes and atmospheric gases changes
• Energy from the sun causes water to evaporate from the sea and land (1)
• Water can also evaporate from plants called transpiration
• Warm water vapour is carried upwards by the rising air, condensing to form clouds (2)
• Water falls as precipitation and provides fresh water for plants and animals before draining back into the sea (3)
• Carbon Dioxide is removed from the atmosphere through photosynthesis
• During respiration, some carbon is returned to atmosphere
• Carbon can move through the food chain as fats and proteins
• Animals produce waste that is broken down and eaten by microorganisms who release Carbon Dioxide when they respire
• The amount of CO2 released depends on how much organic matter decomposes
• Combustion of materials also returns carbon dioxide to the atmosphere
• Rate of decay is affected by temperature, oxygen and water availability and the number of decay organisms
• Biogas is made from anaerobic decay of waste. It is used to generate electricity but has to used straight away as it cannot be stored
• Batch generators make biogas in batches and are manually loaded up with waste
• Continuous generators make biogas all the time and it is produced at a steady rate
• More waste is being produced which results in the loss of biodiversity
• Sewage and toxins from industry pollute water sources
• Toxins are used in farming and lots of nuclear waste is buried affecting the land
• Smoke and acidic gases can pollute the air
• Sulphur Dioxide causes acid rain
• Gases in the atmosphere act as an insulater, preventing the Earth from becoming too hot
• Higher temperatures result in thermal expansion and rising sea levels from melting ice caps