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
Distinct vertical layering of plants that occurs as a response to abiotic factors
Canopy – Kauri, Rimu, Totara
Sub-canopy- lancewood, kowhai
Shrub layer – Rangiora, Kawakawa
Ground layer – mosses, liverworts
Leaf Layer – invertebrates, leaf litter
Vines (lianas) and Epiphytes
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
SalinityLack of food while the tide is oute.g. Limpets and cats-eyes need to be covered with water before they can start eating
LightGreen seaweeds highest, brown, and red is the lowest
Wave actionOrganisms 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
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