Slide 1

Relationships between organisms

A love, hate thingEvery organism has its placeEvery organism in an ecosystem has a role or job to carry outThat job and how it uses the conditions around it is called a nicheExamples include: an organisms place in the food web; producer, consumer, decomposer.How it interacts with other living things (biotic factors)Where and how it lives out its lifeResources (abiotic factors) that affect it.Many relationships exist among organisms: How do organisms interact?CompetitionPredation: predator and preySymbiosisMutualismCommensalismParasitism

Competition

Competition exists between members of the same species and between species.What are organisms competing for?Resources: food, water, living space, etc.Predator and preyContrary to common thoughtAn organism wont eat all the prey. What would happen to the predator

Symbiosis..together at last!Sym; togetherBiosis: living

Symbiosis is defined as a relationship when two organisms live closely (in or on) together.Three typesMutualismIll scratch your back if you scratch mine

CommensalismWhen one member in the relationship is benefited and the otherwell no harm, nor help

Parasitism

One member is helped by the relationship and the other is harmed.

SuccessionOrderly, natural changes and species replacements that take place in the communities of an ecosystem.

Often follows a predictable, orderly pattern.Two types: Primary and Secondary

Primary Succession: Starting with no soils

Step 1 - Bare rock (0-1 years)Lichens grow on the bare rock (a pioneer species). As they die, the decaying lichens form soil so moss can grow.

http://botit.botany.wisc.edu/images/veg/Step 2 - Grassland (2-4 years)Grasses and other small plants grow; out-competing the mosses for sunlight.

http://botit.botany.wisc.edu/images/veg/

Step 3 - Transitional or shrub (5-20 years)Small shrubs such as dogwood and sumac begin to dominate.

Step 4 - Coniferous Forest (20-100 years)Pines and fir trees begin to shade out the smaller shrubs

http://botit.botany.wisc.edu/images/veg/Pine forest

Step 5 - Deciduous Forest (100-200 years)Large, slow-growing trees such as oak, maple and hickory replace the pinesif the abiotic factors allow it to happen.

Secondary Succession:

Succession that occurs after a community is disrupted by natural disasters or human activity. Examples = fire, flood

*Occurs in a shorter amount of time because soil and sometimes seeds present.

Yellowstone National Park (after a 1988 forest fire)Climax Community = a stable, mature community that undergoes little or no change in species.

Southern WI = Prairie

Baraboo = deciduous forests

Northern Wa = temperate rainforest in Olympics

http://botit.botany.wisc.edu/images/veg/