Life cannot exist without energy
Energy flows in one direction thru the ecosystem eg. Green plants (autotrophs) harness light energy from the sun. An another consumers eat the autotrophs and other consumers. This flow of energy is a consequence on the laws of thermodynamics, were in sense that energy can neither be stored or created, but is transferred from one type to another. At which sun is converted to heat. The transfer of energy in an ecosystem, can be showed in a number of ways eg as a food chain, food webs, pyramids of no, pyramids of biomass, pyramids of energy. Simplest representation is the food chain in which one species is connected to another by arrow showing, eaten by Primary consumer, is eaten by secondary consumer, which is eaten by tertiary consumer. Eg Euglena – water flea- minnow –needlefish- Osprey. Phyto-plankton – zoo plankton- small fish- Birds.
Our food chains is limited to 4 or 5 links. Won’t jus go on, because a high amount of useful energy is consumed converted to heat. Food chains show hw species like insectida are transferred in the ecosystem.But don’t show the complex relationships that exist in dat ecosystem. Food web- most accurate
Show inter-connections btw the species in a food chains. But food web are also limited, very often relationships are so complex, that related species with similar diet are grouped together on the food web. Hence can only a limted part of the ecosystem, eg decomposers are usually left out. Also does not give any info on amount of energy flows form one part of an ecosystem to another. Primary producer- secondary producer-
In our attempt to gain answers to our curiosity, we use pyramids of numbers , mass and energy. Pyramids-
Graphically shows quantative relationships btw organisms at each tropic level. We represent each level with rectangle, the length of...
Please join StudyMode to read the full document