2.2,2.5 eco intro[1]

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overview

You will investigate and understand

dynamic equilibria within populations, communities, and ecosystems.

Key concepts include:

• interactions within and among populations

• nutrient cycling with energy flow through ecosystems;

• the effects of natural events and human activities on ecosystems; and

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What is ecology?

Ecology- the scientific study of

interactions between organisms and their environments,

focusing on energy transfer

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What do you mean by environment?

The environment is made up of two factors:

Biotic factors- all living organisms inhabiting the Earth

Abiotic factors- nonliving parts of

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Organism

Population

Community

Biosphere

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Biosphere

• The biosphere, like the human body, is made up of systems that interact and are dependent on

each other.

The biosphere’s systems are called

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Ecosystem- populations (biotic)in a community and the abiotic factors with which they interact (ex.

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Abiotic interactions

All ecosystems must have a

constant source of energy (usually the sun) and cycles or systems to reuse raw materials. Examples are the water, nitrogen and carbon

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Biotic interactions:

Feeding Relationships

• There are 3 main types of feeding

relationships

1. Producer- Consumer 2. Predator- Prey

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Feeding Relationships

Producer- all

autotrophs (plants), they trap energy from the sun

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Feeding Relationships

Consumers- all heterotrophs: they

ingest food containing the sun’s energy

• Herbivores

• Carnivores

• Omnivores

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Primary Consumers

Herbivores

– Eat plants

• Primary consumers

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Consumers

Carnivores-eat meat

• Predators

– Hunt prey

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Consumers

Omnivores -eat

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Clean up Crew

• Many organisms will not be eaten until they die.

• A variety of organisms who are still

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Consumer Clean up crew:

• Scavengers

– Feed on carrion, dead animals

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Consumer Clean up crew:

• Detrivores

• Feed on dead plant

matter, smaller dead animals and the remains left behind by

scavengers.

• Ie worms, beetles,

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Consumer Clean up crew:

Decomposers

• Breakdown the

complex compounds of dead and

decaying plants and animals into simpler molecules that can be absorbed

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Ecological Niche

• A plant's or animal's ecological niche is a way of life that is unique to that species.

• Niche and habitat are

not

the same. While many species may share a habitat, this is not true of a niche. Each plant and animal

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• The niche describes the species' role or function within this community.

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Symbiotic Relationships

Symbiosis- two species living together

3 Types of symbiosis:

1. Commensalism 2. Parasitism

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Commensalism-one species benefits and the other is

neither harmed nor helped

Ex. orchids on a tree

Epiphytes: A plant, such as a tropical orchid or a bromeliad, that grows on another plant upon which it depends for

mechanical support but not for nutrients. Also called

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Commensalism-one species benefits and the other is

neither harmed nor helped

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Parasitism-one species benefits (parasite) and the other is harmed (host)

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Parasitism- parasite-host

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Mutualism-beneficial to both species

Ex. cleaning birds and cleaner

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Mutualism-beneficial to both species

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Type of

relationship Species harmed Species benefits Species neutral Commensalism

Parasitism

Mutualism

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Trophic Levels

• Each link in a food chain is known as a trophic level.

• Trophic levels represent a feeding step in the transfer of energy

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Trophic Levels

Biomass- the amount of organic matter comprising a group of organisms in a habitat.

• As you move up a food chain, both

available energy and biomass decrease.

• Energy is transferred upwards but is

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Trophic Levels

Producers- Autotrophs

Primary consumers- Herbivores

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An Inefficient System

• energy is stored chemically in the bonds of glucose molecules

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Energy & “Trophic” Levels

Producer Primary Consumer Secondary Consumer Tertiary Consumer

Flow of Energy Sun

2nd Law of Thermodynamics Energy is lost during conversion

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Trophic Levels

Food chain- simple model that

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Trophic Levels

Food web- shows all possible

feeding relationships in a

community at each trophic level

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Why does diet

matter?-Energy decreases as it moves up the food chain.

complete worksheets: “Going with the Flow”

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Food chain Food web

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Discuss field study

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Handouts

• Complete food web questions • Complete food web worksheet

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Can you make a food web showing the feeding relationships between the following arctic organisms?

Arctic organism Food

Wolf Caribou, musk oxen, arctic hares, lemmings, arctic fox

Caribou Plants (grass and lichen)

Lemming Plants (berries, lichens, seeds)

Arctic fox Lemmings, hares,

Polar bear Seals, lemmings, arctic fox

Arctic hare Plants (willow)