BIOL-2356EL Lecture Notes - Lecture 4: Cyanobacteria, Biotic Component, Eutrophication
Document Summary
Biotic community + abiotic environment functioning as a system ex: forest, lake, pond. The systems we isolate mentally are not only parts of larger ones but overlap, interlock and interact with each other. All systems require energy: ecosystems run mostly with solar energy. Green plants, algae and some bacteria get their energy from sunlight : autotrophs. Some organisms require for their energy needs other organisms: heterotrophs. Ecosystems have a biotic and abiotic component (atmospheric). The biotic component consists of producers (autotrophs) and consumers (heterotrophs) In photosynthesis they fix the energy of sunlight and the inorganic atmospheric co2 to sugars. Do not need other organisms as a source of energy. Photosynthesis - light as a source of energy. Chemoautotrophy - chemicals as a source of energy. Rely on other organisms (living or dead) as a source of energy and nutrients. Green plants are the most important group of primary producers on land.