Where does all the energy originate? Agenda for Monday Sept 26 th 1.Ecology Video 2.Ecology Notes Learning Targets 1.I can differentiate between abiotic and biotic factors 2.I can draw a food chain/food web and identify the trophic levels 3.I can describe how energy is transferred through a food web/food chain

Ecology Def. – study of relationships between living organisms and their environment

Organization Organisms – individual member of a population Populations – members of a single species that live in once place at a single time Communities – living parts of ecosystem – Lake – fish, turtle, algae, bacteria, etc

Organization Ecosystem – all organisms and non-living environment in an area – Biotic – living – Abiotic – not living Biome – large group of organisms that share same climate and have similar types of communities Biosphere – every living thing on Earth

Habitat vs. Niche Habitat – an area where an organism lives Niche – the role a species plays in its environment – range of conditions the species can tolerate – Methods to obtain resources – # of offspring – Other interactions Compare and contrast habitat and niche

Food Webs and Food Chains All energy in an ecosystem starts with the SUN Producers – use sun’s energy – Make their own food - autotrophs – Plants

Consumers – eat other organisms (heterotrophs) – Primary – eat plants – Secondary – eat other consumers

Herbivores – plant eaters Carnivores – meat eaters Omnivore – both meat and plants Detritivores – eat decomposing matter (detritus)

Decomposers Decomposers – eat dead organisms (detritivores)

Food Chain Pathway of feeding relationships among organisms in an ecosystem – Results in energy transfer (shown by arrows)

Food Web Interrelated food chains – Shows energy transfer (shown by arrows)

Energy Pyramid Shows trophic (feeding) levels and energy available to each level – 10% energy gets passed to each level – Lose 90% to living (respiration)

More biomass at the bottom of a food chain/food web. As we go up in a food chain/food web there is les mass.

More organisms at the bottom of a food chain/food web. More producers As we go up in a food chain/food web there are less organisms. Less secondary consumers

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Human Impact on food chains/food webs Introduce toxins – DDT and eagles

Biomadnification and bioaccumulation Biomagnification = the increase in concentration of toxin as it passes through successive levels of the food web

Biomadnification and bioaccumulation Bioaccumulation = the accumulation of a contaminant or toxin in or on an organism from all sources (e.g., food, water, air) –accumulate in living things and stored faster than they are broken down or excreted

Biomagnification of a DDE in Aquatic Environment Tertiary Consumer 3-76 µg/g ww (fish eating birds) Level Amount of DDE in Tissue Secondary Consumers 1-2 µg/g ww (large fish) Primary Consumers (small fish) µg/g ww Primary Producers (algae and aquatic plants) 0.04 µg/g ww

Calculating amounts Suppose an osprey eats 200g of fish per day. The fish tissue consumed by the osprey has an average DDT concentration of 0.1μg/g. How much DDT is the osprey consuming in one day? (200g fish/day)(0.1 μg DDE/g fish) = 20 μg DDT/day