Topic 5.1 – 5.3 Mrs. Milam Adapted from Ms. Davies

Ecology: – Environment has 2 components: : nonliving factors (soil, water, weather, pH) : living factors (all forms of life)

Ecologists study environments at different levels of organization: – Population: Species: Habitat:

– Community: – Ecosystem:

– Biosphere:

Organism Population Community Ecosystem Biome Levels of Organization

Almost all activities of life are powered by Energy enters ecosystems through

Autotrophs or producers: convert (food); become the Heterotrophs: an organism that

Heterotrophs include: – Consumers: Detritivores: organisms that (ex: earthworms, maggots, slime molds) Saprotrophs: (ex: bacteria, fungi)

The feeding relationships between organisms can be organized into a food chain. – A food chain is a

Food chains: – The arrow is pointing at the organism doing the consuming Helioconius butterfly KcZV7wg/TGK9bg09fAI/AAAAAAA AAXs/EpokiiPbkQA/s1600/Helico nius_erato_001.JPG Passionflower Violet_Passion_Flower.jpg#filelink s Jaguar Tegu lizard /Tupinambis

Natural communities have food webs rather than simple food chains – A food web shows

An ecological niche is unique to each species and includes all aspects of it’s way of life: – Physical – Physical (range of temp it can withstand, pH of soil, amount of moisture it needs, etc.) – – trophic level – Organism’s role in ecosystem – it’s “occupation”

Trophic levels represent “Feeding level”: 1. – autotrophic organisms that make food 2. – herbivores; eat producers 3. – eat primary consumers & possibly producers 4. – eat secondary consumers & possibly primary consumers & producers 5. – eat tertiary consumers & possibly secondary & primary & producers *Top carnivore – top of the food chain

Trophic levels can be studied by looking at – each step in a food chain represents a

Which tropic level?

Can you label the trophic levels for this food web?

Energy flows from one trophic level to the next – Producers get their energy from the sun through photosynthesis. – Energy then flows from the plant to the primary consumer that eats it – The energy transfer continues from one level to the next Transfer of energy through trophic levels is

Each level only passes approximately – Why? – Some of the energy is used for – Some of the energy is – Some of the energy is (ex. Cellulose) Less and less energy is available to subsequent levels

The amount of life an ecosystem can support depends on – Gross primary productivity – Plants use 10 – 70% of their gross productivity for their own energy needs

– Net primary productivity – Measured in  Also measured in – dry weight of organic matter – Productivity of an ecosystem is influenced by many factors (amount of sun, water, temperature)

Transfer between trophic levels can be studied through ecological pyramids 1.Pyramid of energy –

2.Pyramid of Numbers – number of individuals at each trophic level Generally

3.Pyramid of Biomass – shows the amount of biomass at each trophic level

Energy moves through the communities of ecosystems in – Energy enters ecosystems as, is, but is.

Nutrients constantly – Nutrients – Saprotrophs (bacteria and fungi)