Biogeography• The study of where organisms

live.• Bio- Life• Geo- Earth• Graph- Description

Dispersal

oDispersal - The movement of organisms from one place to another

o3 main means of dispersal.– Wind:

•Seeds•Spores•tiny spiders•small light organisms

Dispersal

– Water: •Floating objects•Coconuts•Leaves•Insects

– Other Living Things•Birds: seeds•Ducks: algae and fish eggs•Dogs and Cats: organisms in their fur•Humans: (all sorts of things!!) •(Think about customs at the airport.)

Dispersal

• Native Species: – a species that has naturally evolved in

an area.

Dispersal

• Exotic Species: – a species carried to a new location.– Consume food sources that native species

would eat, leaving insufficient food. – Occupy safe or supportive habitat, leaving a

reduced amount of habitat for natives. – Serve as food for native species but lack

certain essential nutrients, leading to death of native offspring.

– Consume eggs, young, and adults of native species

Dispersal• There are limits to organisms

reaching other parts of the world.– Physical barriers:

•Water•Mountains•Deserts

– Competition:•Organisms competing for resources with

existing species.– Climate:

•Organisms unable to survive and thrive due to the temperature or amount of water.

Biotic vs. Abiotic• Biotic factors

are all the living things or their materials that directly or indirectly affect an organism in its environment.

• Abiotic factors are those non-living physical and chemical factors which affect the ability of organisms to survive.

Abiotic FactorsSome Abiotic Factorso light intensity o temperature range o type of soil or rock o pH level

(acidity or alkalinity) o water availability o dissolved gases o level of pollutant

Biotic Factors

oParasitismoPredationoMutualismoCommensalis

moCompetition

ParasitismThe association in the parasite host relationship is one in which one organism benefits from the relationship and the other is disadvantaged. The parasite feeds upon the tissues or organism

Mistletoe growing on a tree. AndFleas on a dog.

Mutualism• Mutualism

refers to the relationship of two organisms where both benefit from the association.

This lichen growing on the trunk of a tree.

Commensalism• This is where

one species has an advantage and the other is not harmed.

A bird building its nest in a tree.

Predationo This may be a

producer/consumer relationship.

o Or a predator/prey relationship

o Or a scavenger relationship.

Successiono Succession: the series of changes

that occur in a community.

o 2 types of succession!

Primary Successiono The change in a community that no

ecosystem previously existed.o Example: New Island

o Pioneer species: – The first species to populate an area. (moss)

Secondary SuccessionoThe

disturbance of an existing ecosystem.

oExample: – Fire– Tornado– Farming– Mining