Kinds of Food Webs
Food webs are necessarily aggregated and only illustrate a tiny portion of the complexity of real ecosystems. For example, the number of species on the planet are likely in the general order of 107, over 95% of these species consist of microbes and invertebrates, and relatively few have been named or classified by taxonomists. It is explicitly understood that natural systems are 'sloppy' and that food web trophic positions simplify the complexity of real systems that sometimes overemphasize many rare interactions. Most studies focus on the larger influences where the bulk of energy transfer occurs. "These omissions and problems are causes for concern, but on present evidence do not present insurmountable difficulties."
There are different kinds or categories of food webs:
- Source web - one or more node(s), all of their predators, all the food these predators eat, and so on.
- Sink web - one or more node(s), all of their prey, all the food that these prey eat, and so on.
- Community (or connectedness) web - a group of nodes and all the connections of who eats whom.
- Energy flow web - quantified fluxes of energy between nodes along links between a resource and a consumer.
- Paleoecological web - a web that reconstructs ecosystems from the fossil record.
- Functional web - emphasizes the functional significance of certain connections having strong interaction strength and greater bearing on community organization, more so than energy flow pathways. Functional webs have compartments, which are sub-groups in the larger network where there are different densities and strengths of interaction. Functional webs emphasize that "the importance of each population in maintaining the integrity of a community is reflected in its influence on the growth rates of other populations."
Within these categories, food webs can be further organized according to the different kinds of ecosystems being investigated. For example, human food webs, agricultural food webs, detrital food webs, marine food webs, aquatic food webs, soil food webs, Arctic (or polar) food webs, terrestrial food webs, and microbial food webs. These characterizations stem from the ecosystem concept, which assumes that the phenomena under investigation (interactions and feedback loops) are sufficient to explain patterns within boundaries, such as the edge of a forest, an island, a shoreline, or some other pronounced physical characteristic.
Read more about this topic: Food Web
Famous quotes containing the words kinds of, kinds, food and/or webs:
“To see self-sufficiency as the hallmark of maturity conveys a view of adult life that is at odds with the human condition, a view that cannot sustain the kinds of long-term commitments and involvements with other people that are necessary for raising and educating a child or for citizenship in a democratic society.”
—Carol Gilligan (20th century)
“There are two kinds of timidity—timidity of mind, and timidity of the nerves; physical timidity, and moral timidity. Each is independent of the other. The body may be frightened and quake while the mind remains calm and bold, and vice versë. This is the key to many eccentricities of conduct. When both kinds meet in the same man he will be good for nothing all his life.”
—Honoré De Balzac (1799–1850)
“There is no instant of time when one creature is not being devoured by another. Over all these numerous races of animals man is placed, and his destructive hand spares nothing that lives. He kills to obtain food and he kills to clothe himself; he kills to adorn himself; he kills in order to attack and he kills to defend himself; he kills to instruct himself and he kills to amuse himself; he kills to kill. Proud and terrible king, he wants everything and nothing resists him.”
—Joseph De Maistre (1753–1821)
“Sometimes outside beneath a bombers’ moon
You stood alone to watch the searchlights trace
Their careful webs against the boding sky,”
—Edgar Bowers (b. 1924)