Organisation of an ecosystem

• The feeding relationships between organisms in an ecosystem can be seen in food chains.
• Sampling allows us to measure the abundance and distribution of these species.
• Predators and prey are examples of feeding relationships.
• Experimental methods using quadrats and transects are used to study feeding relationships in an ecosystem.
• Measuring population size in a habitat is a practical way to study feeding relationships.
• The mean, median and mode are used to calculate averages in ecosystem studies.
• Materials are cycled in an ecosystem through the carbon and water cycles.
• An ecosystem can be categorized as a close ecosystem or a far ecosystem based on the interaction between a community and its environment.
• A community is defined as all the organisms that live in a habitat (plants and animals).
• An ecosystem is the interaction of two or more populations of organisms in their environment.
• Producers and consumers are examples of feeding relationships.
• Feeding relationships show what organisms eat or are eaten by others and through this the levels of organisation in an ecosystem.
• The feeding relationships between organisms in an ecosystem can be seen in food chains.
• Food chains and food webs are ways of showing the feeding relationships in an ecosystem.
• Sampling allows us to measure the abundance and distribution of these species.
• A habitat is a place where plants, animals and microorganisms live.
• A simple example of a food chain is: grass → rabbits → foxes.
• Decomposers release enzymes onto the dead matter and afterwards, consume the broken down substances.
• Oxygen is produced as a by-product of photosynthesis.
• These photosynthetic organisms convert energy from the sun into glucose during photosynthesis, producing biomass.
• Algae subsumed within plants and some bacteria are also photosynthetic.
• The next consumer is the secondary consumer, an organism that obtains its energy by eating the primary consumer.
• All animals above the producer are called consumers.
• Photosynthesis is a chemical process used by plants to make glucose and oxygen from carbon dioxide and water, using light energy.
• Decomposers are bacteria and fungi, which break down dead organisms in a process called decomposition or rotting.
• When organisms die and decompose, plants absorb the broken down nutrients through their roots.
• The numbers of predators and prey in a healthy, balanced ecosystem remain fairly constant and can go up and down during each year but generally over the years, these increases and decreases remain fairly constant.
• Decomposers form a vital role in the recycling of matter.
• The first consumer is the primary consumer, an organism that eats a producer such as a herbivore.
• Biomass is the dry mass of an organism which feeds the rest of the food chain.
• The top animal in the feeding relationship is called the apex predator.
• Animals that hunt and kill others are called predators, and those that are hunted and killed are called prey.
• At the base of almost every food chain is a producer, which are plants that begin food chains by making energy from carbon dioxide and water.
• If numbers of either predators or prey increase or decrease it could be due to a change in the abiotic factors, like water or sunlight, or biotic factors, like a new predator or pathogen.
• The numbers of predators and prey for certain ecosystems such as the Canadian Lynx (wild cat) and hare have been recorded over many years and found to change in a regular cycle, this is known as a predator-prey cycle.
• In a predator-prey cycle, there is almost always more prey than predators and the following patterns occur: the number of predators increases because there is more prey, the number of prey reduces because there are more predators, and the number of predators reduces because there is less prey.
• The feeding relationships between organisms in an ecosystem can be seen in food chains.
• Sampling allows us to measure the abundance and distribution of these species.
• The selection of subjects included in a study is called sampling.
• The area or part of population looked at in a study is called a sample.