Ecology

• An ecosystem is the interaction of a community of living organisms (biotic) and the non-living parts of their environment (abiotic)
• competition- plants often compete for light, space, water, minerals, and other resources
• independence- other species may depend on each other for shelter and food
• biotic factors include food, new predators, competition and new pathogens
• abiotic factors include light intensity, temperature, moisture, and soil pH, water , wind intensity and direction, carbon dioxide and oxygen
• organisms have features that allow them to survive in their environment These adaptions may be strucural, behavioural or functional
• Some organisms live in environments that are very extreme, such as at high temperature, pressure or salt concentrations these are called extremophiles
• Food chains begin with a producer which synthesis molecule. This is usually a green plant or alga which makes glucose by photosynthesis
• Producers are eaten by the primary consumer and then by the secondary consumer and then by the tertiary consumer
• Consumers that kill and eat other animals are predators and those eaten are prey
• The carbon cycle returns carbon from organisms to the atmosphere as carbon dioxide to be used by plants in photosynthesis
• The water cycle provides fresh water for plants and animals on land before draining into the seas. Water is continuously evaporated and precipitated
• Biodiversity is the variety of all the different species of organisms on earth or within an ecosystem
• a great biodiversity ensures the stability of an ecosystem by reducing the dependence of one species on another for food, shelter and the maintenance of the physical environment
• Waste management- Rapid growth in human population and increase in the standard of living mean that increasingly more resources are used and more waste is produced
• Different types of pollutants include chemicals such as pesticides, fertilisers and sewage effluent; noise pollution caused by traffic and industry; light pollution from street lights and buildings at night; and littering
• Land use- humans reduse the amount of land available for other animals and plants by buildings, quarrying , farming and dumpin waste
• Land use - the destruction of peat bogs and other areas of peat reduce the area of this habitat and thus the variety of species , plants and animals that live there
• Environmental implications of deforestation

  -provide land for cattle and rice fields

  -grow crops for biofuels
• global warming- the increase in methane and carbon dioxide in the atmosphere
• consequences of global warming

  -loss of habitats

  -plants growth
• maintaining biodiversity

  -breeding programmes for endangered animals

  -protection and regeneration of rare habitat

  -recycling resources rather then dumping into landfills

  -reduction of deforestation and carbon dioxide emissions by some governments