Download Ecosystems PowerPoint #2

Ecosystems
Basics
In order for an organism to grow, survive and
perpetuate their species, they must obtain the necessary
resources.
Every organism needs certain things to survive. h
Each population within an ecosystem has a carrying
capacity. This means they can only reach a certain size.
What sorts of things would keep a population from
becoming really HUGE?
The size of the physical environment
The ecosystem that contains the things that organism needs
to survive is a certain size and they cannot leave it.
Ilha de Queimada Grande (Snake Island)
2. Disease
They become sick and perish
Abiotic factors available to them
Light
Temperature
Water
Soil
Space for shelter
Biotic interactions
What do I mean by this?
Competition
Two organisms, of the same population or different
populations, competing for the same resources
What are some of these things that organisms compete for?
Deer game
Predation
One organism kills another organism
Facilitation
1. Mutualism - both species benefit
1.
2.
3.
4.
The
The
The
The
bee and the flower
spider crab and the algae
bacteria and the human
oxpecker and the zebra
Facilitation
2. Commensalism - One benefits and the other is unaffected
1. The whale and the barnacles
2. The clownfish and the anemones
3. The burdocks seeds and the fur
Feeding Hierarchy
Trophic levels:
Producers
An organism that can make its own energy through biological
processes (usually photosynthesis)
Trophic Levels:
Consumers
Organisms that eat producers
1. Primary consumers (usually herbivores) - eat producers
2. Secondary consumers (usually carnivores) eat primary
consumers
3. Tertiary consumer - top of the food chain, feeds only on
secondary consumers
Trophic levels:
Decomposers
An organism, usually a bacterium or fungus, that feeds on
and breaks down dead plant or animal matter, thus making
organic nutrients available to the ecosystem
Food webs
simple
More complex no composers
With decomposers
Because there are so many factors and everything is
interdependent, ecosystems are always changing.
If you change one factor, it can affect many other
things.
1.
Take away a biotic or abiotic component (i.g. extinction)
2. Add a biotic or abiotic component (i.g. invasive species)
What would you do to lower the amount of snakes on Snake
Island?
What would you do to lower a population of deer on an
island?