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Patterns in a community. Community. Is all the organisms that live within a defined area and their interactions What are the 3 patterns you NEED to be aware of? Zonation, stratification, and succession http://www.youtube.com/watch?v=k-OOfW6wWyQ. Stratifiction.
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Community • Is all the organisms that live within a defined area and their interactions • What are the 3 patterns you NEED to be aware of? Zonation, stratification, and succession http://www.youtube.com/watch?v=k-OOfW6wWyQ
Stratifiction • Distinct vertical layering of plants that occurs as a response to abiotic factors
Zonation • Horizontal bands of organisms that occur across a particular habitat or area, due to a environmental factor
Zonation on the rocky shore • Tidal movement. (i.e. exposure to sea water and air) • Competition for space and food increases down the shore from high to low tide.
Zonation on Mt Ruapehu • Temperature or altitude change from bottom to top. • Zonation in plant species. • Moving down the mountain, competition between plants for light, space and nutrients increases.
Zonation • The plants and animals in the various zones, have different adaptations to fit slightly different environments. • Over-lap into other zones • POL: Factors that lead to zones on a rocky shore p.g. 58-59
Factors that lead to zones on the rocky shore • Exposure to air: Periwinkles and barnacles (found at the top end), can glue themselves into a crevice or shut their trapdoors. Seaweeds are found in the pools or lower down as they dry out.
Greater exposure to extremes of temperature • Salinity • Lack of food while the tide is out e.g. Limpets and cats-eyes need to be covered with water before they can start eating
Light Green seaweeds highest, brown, and red is the lowest • Wave action Organisms higher up on the shore need to be able to fix themselves tightly to the rock e.g. barnacles, mussels, kelp (permanently) or periwinkles, chitons and limpets (temporarily).
Succession • The change in species over time • Primary and Secondary
Primary Succession • Occurs when plants start to grow on an area that had no previous life. • Starts on bare land • New Sand dunes on a shore, cooled lava from volcanic eruption, or an area behind a retreating glacier
Secondary Succession • Occurs when previously inhabited land is cleared by an environmental event such as a landslide, fire, flood, human activity • The soil however is intact
Succession Dictation (Primary) Listen and draw