Ecosystems
Learning outcomes
distinguish between living and non living things
describe differences between plants and animals
understand how plants and animals are adapted to their environment
identify characteristics of herbivores, carnivores and omnivores
understand the feeding relationships shown in a food chain and food web
construct food chains and food webs using information
discuss the impact of adding and removing organisms from a community
investigate the impact of introduced species on the NZ ecosystem
Ecological Niche
Niche is a complex term that has itself evolved over time. An organisms niche is where it best fits into an ecosystem.
If you can think of an organisms habitat as its address, then it's niche could be describe as its "profession".
Niche is a combination of where an organisms lives (its habitat), how it make a living there (adaptations) and the role it performs in the community. It includes the sum total of an organisms requirements; it's way of life.
When describing an organisms niche, you should try to include...
Its habitat (abiotic and biotic factors, including any if it's requirements)
Its adaptations (any structural, physiological or behavioural traits that enable to survive in its habitat)
Its role (e.g. producer, how it fits into a food web or interacts with other species)
What is an ecosystem?
An ecosystem is made up of animals, plants and bacteria as well as the physical and chemical environment they live in.
The living parts of an ecosystem are called biotic factors while the environmental factors that they interact with are called abiotic factors.
Because living things both respond to and are influenced by their environment, it is important to study both factors together to get a full picture.
Producers
Plants are called producers. This is because they produce their own food! They do this by using light energy from the Sun, carbon dioxide from the air and water from the soil to produce food - in the form of glucose/sugar.
The process is called photosynthesis
Consumers
Animals are called consumers. This is because they cannot make their own food, so they need to consume (eat) plants and/or animals.
There are 3 groups of consumers.
Animals that eat only plants. (Herbivores)
Animals that eat only animals.(Carnivores)
Animals that eat both animals AND plants. !(Omnivore)
Decomposer
Bacteria and fungi are decomposers. They eat decaying matter - dead plants and animals and in the process they break them down and decompose them When that happens, they release nutrients and mineral salts back into the soil - which then will be used by plants!
Video on Herbivore, carnivores, and omnivores
Worksheet on Producers, Consumers, and Decomposers
Natural selection is the process where organisms with favourable traits are more likely to reproduce. In doing so, they pass on these traits to the next generation.
Over time this process allows organisms to adapt to their environment.
This is because the frequency of genes for favourable traits increases in the population.