Warm Up

Shown here is some lichen on a rock . . • A. What is lichen?• B. What type of biotic interaction would it

be classified as? Why?• C. What role does it serve in ecological

succession?

Once you’ve answered the questions above, sign up for a biome to do your homework on – the sign up is on the front board on the clipboard

What Shapes an Ecosystem?

Chp 4-2

How do abiotic factors influence biotic?

Niche vs. habitat

Habitat

the address

Niche

the role

Biotic Interactions

Competition & the Competitive Exclusion Principle

Biotic Interactions

Predation (+/-)

Symbiotic Biotic Interactions

Mutualism (+/+)ant/catepillar

Commensalism (+/0)

Parasitism (+/-) (how’s this different from predation?)

Succession• Orderly change over time of natural

species replacement in a community or ecosystem

Succession communities:

1. Pioneer species

2. Intermediate species

3. Climax community

Pioneer species:

• Lichens (algae & fungi) break apart rock to make soil

• Grasses• Annual flowers• Mosses

Climax Community: final set of organisms suited to that climate

Types of Succession

Primary

• 1st time plants

or animals are

established

• New island

• Volcanoes

• Glaciers

• Bare soil, rock

Secondary• After a “blowout”• Re-establish a

community• Already had

living organisms• Fire, flood,

human disruption

New island= Primary Succession

Secondary Succession will follow!

Primary Or Secondary?

BOTH PRIMARY & SECONDARY have

these Succession communities:

1. Pioneer species

2. Intermediate species

3. Climax community

San Diego Succession