Ecosystems and interactions

Re-cap - definitions Use the find out sheet to find a person who can tell you what one of these means and get them to sign the box: species, biodiversity, population, producer, consumer, herbivore, carnivore, omnivore, predator, prey, food chain, food web

Today we are learning about Ecosystems By the end of the lesson you should: Know and be able to state the definition of an ecosystem Know that organisms interact with each other in ecosystems Know and explain how organisms affect each other in food webs

An ecosystem is a community of plants, animals and smaller organisms that live, feed, reproduce and interact in the same habitat or environment. The non-living components include temperature, pH, CO2 , O2 and other chemicals. Some ecosystems are very large. For example, many bird species nest in one place and feed in a completely different area. On the other hand, some ecosystems may be physically small, like in a meadow at the edge of a forest, or in a coral reef in the ocean.

There are many ecosystems in the world

And there are a variety of ecosystems in Scotland such as: Woodland Urban green spaces & gardens And in each of these big areas there are many different smaller ecosystems

Scottish Natural Heritage (SNH) are one of Scotland’s national organisations that have documented the ecosystems found in Scotland including: Mountain heaths & willow scrub Inland rock Ponds Heaths Wood pasture and parkland Arable fields Gardens and allotments Seabed Atlantic hazel Traditional orchards and wood pasture Peat bogs Oak woods Lowland wetlands Minor woodland types Birch woods Caledonian pinewoods Grasslands Rivers, streams and headwaters Ash woods Lowland grassland Lowland heaths Coastal habitats Wet woods Freshwater lochs

On the SNH website many of these ecosystems are described in detail. You will pick one of these ecosystems to research further from the SNH website. (This is a very short research task) You will need to fill in the ecosystem sheet provided. You will need to be prepared to share your information with other people.

In ecosystems the organisms are inter-linked in many ways: Shelter is provided by plants for animals Plants are food for animals Animals are food for other animals If ecosystems are disturbed or changed by natural or man-made events then this can have serious consequences for the ecosystem

The feeding relationships in an ecosystem can be represented by drawing food chains and food webs. A food chain could look like this Grass Rabbit Fox The arrows represent the flow of energy between the different organisms. Food webs are just many food chains from an ecosystem linked together. They show how complex and interlinked the relationships are between organisms in an ecosystem.

A typical ocean food web Pick out some food chains from this food web

Using the Scottish Highlands you will now construct some food chains and a food web. Each group or pair needs the organisms cards, the organisms feeding information and a piece of A1 paper. Read the organism feeding information sheet. Use as many cards as possible to construct a food web. You will need to add arrows to connect the organisms. (The organisms cards should be put on the A3 paper and the arrows drawn in with a marker)

A typical Scottish Loch ecosystem food web Look at this and write1 food chain from it

Look at the web again. It has been a very cold winter and all the frog spawn was killed meaning no tadpoles. What changes will this make and why?

Look at the web again. A pesticide has been used to kill the snails as they can spread diseases to sheep like Liver fluke What changes will this make and why?

Interactions in food webs From the following food web answer these questions. What would happen if pollution stopped the plants from growing very well? Dolphins are getting caught in Tuna fishing nets and reducing the dolphin population. What effect will this have on the food web? Herring are being overfished reducing the number Reproducing.

You will be given a summary note with gaps. Fill them in using your knowledge, check with the master below An ecosystem is made up of all the organisms living in a particular habitat and the non-living components with which the organisms interact. Organisms in a food web interact with each other and are dependant on each other. If one factor changes in an ecosystem it will affect other parts of the ecosystem.