Explain the energy flow of ecology?
Energy flow: As you can see, energy flow is one way in an ecosystem. Energy is not recycled. The ultimate source of energy that powers ecosystems, for the most part (aside from organisms that derive energy from chemicals), is the sun. Electromagnetic radiation from the sun in the part of the spectrum known as visible light (Wavelengths between 380 and 750 nanometers) is absorbed by plants and converted by photosynthesis into a biochemical form that can be used by other organisms. Remember that only plants (autotrophs: auto=self; trophe=feeding) have the molecular apparatus (chlorophyll in chloroplasts) that can change light energy into usable biochemical forms such as ATP and carbohydrate sugars.
So, in an ecosystem, the autotrophs, consisting of all of the photosynthetic plants, are considered to be the "producers." In other words, they "produce" the biochemical forms of energy that are used by the other organisms in the ecosystem. Therefore, all of the other organisms in an ecosystem would be considered "consumers," or heterotrophs (heterotroph: hetero=other; trophe=feeding).
Consumers are categorized according to whether they are "primary," "secondary," or "tertiary" and beyond. Primary consumers are herbivores, or animals that consume plants. Secondary consumers are carnivores (those that feed on animals), or omnivores (those that feed on both plants and animals). Detritivores feed on detritus, or litter, and are part of the ecosystem component known as the decomposers. It is possible for energy to be passed from a dead animal carcass to a decomposer (fungus or protozoan, for instance), and then from there to another omnivore or detritivore.
Producer Level: However, all energy that flows from level to level within an ecosystem always has a component percentage that is lost as heat to the surrounding environment. This is the reason that energy only flows one way and is not recycled. For example, not all of the sun energy that is captured and converted by plants is passed on to consumer organisms. Of all the energy trapped, a portion of the energy is used by the plant for its own metabolism (energy loss), and some of it is just not accessible by the consumer--for instance, some energy was used to make inedible bark, or perhaps a seed pit!
Primary Consumer Level: An herbivore consumer, in addition to its own metabolism needs, must use some of its energy to forage and first to find food (energy loss), and then to chew it and digest it. As we saw in the preceding paragraph, not everything it eats provides energy, because some parts are indigestible and pass through the digestive tract. So some energy is lost along the way here as heat. Further, not all of the energy the herbivore derives from eating will be accessible to the next level consumer (secondary consumer) either, because some of the energy goes into making herbivore bones, and other non-consumable parts!
The same types of energy conversions and losses occur along the way in all food chains or webs in ecosystems, resulting in ever decreasing amounts of energy at each energy level. In general, energy flow in an ecosystem is one-way, necessitating the constant input of energy from an outside source - in this case, the sun, to power all of the biological processes in an ecosystem.