Energy Flow How does energy move through the ecosystem?

Conservation: Law of Conservation of Matter - –In any ordinary physical or chemical change, matter is neither created nor destroyed, only transformed from one form to another. Law of Conservation of Energy - –In any ordinary physical or chemical change, energy is neither created nor destroyed, only transformed from one form to another.

Energy: 2 nd Law of Thermodynamics: –When energy is changed from one form to another, some energy will be lost to the larger environment. Nothing is ever 100% efficient. This is due to entropy (nature’s tendency towards randomness).

How does energy flow through ecosystems? Food Chain: A simple diagram of one string of feeding relationships in an ecosystem, showing the direction of the transfer of energy in that system. SunGrassRabbitWolf Bacteria Soil

Producers Organisms that make their own food from inorganic molecules and energy. – eg. Plants, blue-green algae –Most accomplish energy building through photosynthesis H Sunlight + CO 2  Sugar + O 2 Inorganic Molecules = molecules that are not part of a living organism Energy is almost always from the sun (very rare exceptions) What are the parts of a food chain?

Consumers Organisms that cannot make own food. –eg. all animals, fungi and most bacteria –Obtain energy by eating other organisms — through a process called cellular respiration Sugar + O 2  CO 2 + H energy

Consumers… Primary consumer (1 0 ) – eats plants (it’s a herbivore) Secondary consumer (2 o ) – eats a primary consumer Tertiary consumer (3 o ) – eats a secondary consumer se2.db_psc-tvl-path-baseX5FtasksX5F4b2eX5Fimage-u-4e2e-z-f.jpe

Consumers… Herbivores – eat plants or algae Carnivores – eat other animals ml/info/whats-a-herbivore.html

Consumers… Omnivores — eat both producers and consumers Scavengers — usually don’t hunt live prey — feed on bodies of dead organisms

Decomposers Bacteria and fungi that break down organic material Decomposers are essential to ecosystem health because they recycle nutrients back for producers to reuse.

Food Chain with Labels 1 0 Consumer Producer herbivore 2 0 Consumer Carnivore Decomposer Sun

Food Web: a group of food chains showing all of the feeding relationships in an ecosystem.

Food Web HumanWolfFox Sheep Bacteria RabbitMiceDeer GrassFlowerCarrots Nutrient Rich Soil Sun

Biological Magnification Increasing concentration of a substance in organisms in higher trophic levels in a food chain or web.

Biological Magnification- accumulation of increasing amounts of toxin within tissues of organisms. Video on Biological Magnification

Food Webs con’t: Trophic level — a layer in the feeding relationship of an ecosystem, one link in the food chain/web. Biomass — total amount of organic material present in a trophic level. Organic = is currently living or lived in the past So, all producers are at the same trophic level and all primary consumers are at the next trophic level.

Energy Pyramids Another way to look at trophic levels. a diagram showing the relative amounts of energy/biomass in the different trophic levels. Lowest trophic levels are at the bottom: Producers have the greatest biomass. Galvbay.jpg

Example of an Energy Pyramid MAN FOX RABBIT 100 % of the sun’s energy 10% 1% 0.1% 10% 1 MAN 10 FOXES 100 RABBITS 1000 Bunches of GRASS 90% Energy Lost during conversion to heat, waste…. Grass Rabbit - The decreasing size of the pyramid shows that each level of the pyramid has a smaller and smaller number of those organisms.