ENERGY FLOW AND NUTRIENT
CYCLING
Ecosystem
• It is an area which is self contained and life supporting. • It contains biotic (including plant, animal and microorganisms) and abiotic or physical factors (including nutrient cycling).
• Examples include: coral reefs, deserts, savannahs and rain forests.
• Several habitats and the communities associated with them make up an ecosystem.
http://www.bloggersbase.com/images/uplo aded/original/c622477c9e5a5d2040c71563 31f799b10498611d.jpeg
The Great Barrier Reef
http://en.wikipedia.org/wiki/File:Judea_2_by_David_Shankbone.jpg
http://students.umf.maine.edu/~orourkcj/As signments/rainforest2.jpg A tropical rainforest
http://en.wikipedia.org/wiki/File:Acacia_Bild1086.jpg
Habitat
• This is the place where an organism lives. It can be considered the address of the organism.
• Examples include woodlands and fresh water ponds. • Sometimes organisms occupy just a small portion of the habitat such as a tree in the woodland or a rock in the pond.
• The tree and rock are referred to as microhabitats. http://www.footprint.org.hk/capitat/website/images/habitat.gif
Ecological niche
• This refers to the role an organism plays in the community. It can be described as the organism’s profession.
• It includes the behaviour of an organism and its interaction with the living (eg. Its competitors) and non-living (eg. Available resources) components.
Ecological niche con’t
• The behaviour includes: growing when predators, competitors and pathogens are scarce. The same species can then be a predator or provide great competition for other species.
Ecological niche con’t
• The ecological niche has two components.
• The food niche is one component of the ecological niche and is defined by the type and quantity of food it consumes.
• The habitat niche is the other component and is defined by its temperature tolerance etc.
• An example of niche description: some fungi are asexual, soil dwelling organisms.