Ecological Relationships 23/02/2019 Ecological Relationships

Ecosystems 23/02/2019 “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) Changes in ecosystems Pollution Human interference Changes in soil conditions

Taking samples of an ecosystem 23/02/2019 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 23/02/2019 A food chain shows where the energy goes in a food chain (in other words, “what gets eaten by what”): Rabbit Cabbage Fox Stoat The arrows indicate where the energy is going Plants convert the sun’s energy into food

Pyramids of number 23/02/2019 In this food chain we can see that the number of organisms in each stage is less than in the previous stage: Cabbage Rabbit Stoat Fox We can draw a “Pyramid of Numbers” to show this pattern: One fox A few stoats Some rabbits Lots of cabbages

“Funny looking” pyramids 23/02/2019 Consider this food chain instead: Tree Greenfly Ladybird Bird One bird Some ladybirds Many greenfly ONE tree