Identify ecosystem boundaries and trace one-way energy flow alongside matter and nutrient inputs, outputs and recycling in IB Biology SL C4.2.1.
Describe the movement of energy and nutrients in an ecosystem.
ecosystem is a community and its abiotic environment;
solar energy collected by autotrophs/plants (via photosynthesis);
moves through trophic levels via food;
only 5 to 20 % transferred from one trophic level to next / never 100 % efficient;
lost as metabolic heat/organic waste;
energy flow can be illustrated by pyramid shape;
organisms absorb nutrients from food/environment;
nutrients occur as complex organic matter in living organisms;
after death, saprotrophic bacteria and fungi (decomposers) breakdown complex organic matter;
breakdown products are simpler substances;
absorbed into plants for resynthesis into complex organic matter/recycled;