What Shapes an Ecosystem?

What Shapes an Ecosystem? Biotic Factors – living/biological influences on organisms within an ecosystem. Examples? Abiotic Factors – physical/non-living influences on organisms within an ecosystem. *Together, biotic and abiotic factors determine the survival and growth of an organism and the productivity of the ecosystem in which the organism lives = habitat (= home of organism; its “address”)

Abiotic and Biotic Factors Abiotic Factors Biotic Factors ECOSYSTEM

Abiotic and Biotic Factors Abiotic Factors Biotic Factors ECOSYSTEM

Biotic vs. Abiotic

Biotic vs. Abiotic

Biotic vs. Abiotic

Biotic vs. Abiotic

The Niche Niche = the ROLE of an organism in its habitat What is the organism’s job? What does the organism do for its environment? The niche is the full range of physical and biological conditions in which an organism lives and the way in which the organism uses those conditions place in food web, range of temperatures needed to survive, food, physical conditions necessary for survival, reproduction, etc. *Competitive Exclusion Principle - no two species can share the exact niche in the same habitat at the same time…Why? One will become extinct.

Warblers and Their Niches Cape May Warbler Feeds at the tips of branches near the top of the tree Bay-Breasted Warbler Feeds in the middle part of the tree Yellow-Rumped Warbler Feeds in the lower part of the tree and at the bases of the middle branches Spruce tree

Community Interactions Powerfully affect an ecosystem Three important types of interactions Competition Predation Symbiosis

Competition Competition – organisms compete for resources (food, water, shelter, etc)

Predation Predation – one organism (predator) captures and feeds on another (prey)

Symbiosis Symbiosis – two species live closely together Three major types of symbiosis Mutualism Commensalism Parasitism

Symbiosis - Mutualism Host Symbiont Example: flower & bee – both organisms benefit from each other Other examples?

Mutualism Examples

Symbiosis - Commensalism Host Symbiont Example: barnacle and whale – one organism benefits, the other is not hurt nor harmed Other examples?

Commensalism Examples

Symbiosis - Parasitism Host Symbiont Example: tapeworm and human – one organism benefits while the other is harmed Other examples?

Parasitism Examples

Ecological Succession Ecological Succession – series of predictable changes that occurs in a community over time *Ecosystems are constantly changing in response to natural and human disturbances. As an ecosystem changes, older inhabitants gradually die out and new organisms move in, causing further changes in the community.

Primary Succession Bare rock to plant community – like on a volcanic island First species to populate are called pioneer species (usually lichens) No soil – have to make it by breaking down rocks first

Primary Succession

Secondary Succession Soil to climax community (stable, mature community) Wildfires, farms, marine environments Soil already there