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Ecological Relationships. W Richards Worthing High School. Please note – some of the animation effects used here only work in PP XP. Ecosystems. Changes in ecosystems. “Ecosystem” is a term used to describe all of the organisms living together as a community in a particular habitat.
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Ecological Relationships W Richards Worthing High School Please note – some of the animation effects used here only work in PP XP
Ecosystems Changes in ecosystems “Ecosystem” is a term used to describe all of the organisms living together as a community in a particular habitat. Ecosystems are constantly changing: Changes in population due to predation, disease etc Physical changes (e.g. temperature change) Pollution Human interference Changes in soil conditions
Classification of Plants We all know that there are many different types of plants, so how do we classify them?
Taking samples of an ecosystem • Using different “sampling techniques” we can measure changes in an ecosystem. The two main measurements are: • The physical conditions of a habitat (temperature etc) • The populations of different species in that habitat Some common ways of measuring… Help! Measuring temp, pH etc Taking animal samples Taking samples using quadrats
Food chains Cabbage Rabbit Stoat Fox Plants convert the sun’s energy into food The arrows indicate where the energy is going A food chain shows where the energy goes in a food chain (in other words, “what gets eaten by what”):
Pyramids of number Cabbage Rabbit Stoat Fox One fox A few stoats Some rabbits Lots of cabbages In this food chain we can see that the number of organisms in each stage is less than in the previous stage: We can draw a “Pyramid of Numbers” to show this pattern:
“Funny looking” pyramids Tree Greenfly Ladybird Bird One bird Some ladybirds Many greenfly ONE tree Consider this food chain instead: