Patterns in a community

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