Food web, (noun, “FOOD WEB”)
A food web is a map of what organisms eat what other organisms in a given area. Those life forms include all the species in that area, such as plants, animals and even microbes. Food webs represent feeding relationships with arrows. Each arrow points from the species getting eaten (the prey) to the species feeding on them (the predator).
Most species in a food web have feeding relationships with many other species. For example, a rabbit may eat grass, wheat or lettuce. That same rabbit may be eaten by a fox or a hawk. Or it may die of natural causes and be eaten by microbes in the soil. Each possible pathway is called a food chain. And each species is a link in that chain. A food web combines all the individual food chains between every species in a given place, or an ecosystem.
By showing who eats who, food webs illustrate how energy travels through an ecosystem. Energy enters most ecosystems through plants or algae, which get their energy from sunlight.
Food webs can focus on different aspects of an ecosystem. For example, a food web of a rainforest ecosystem might start with plants, such as Brazil nut trees (Bertholletia excelsa). Those organisms are, in turn, shown being eaten by animals, such as sloths and monkeys. The end of this food web is likely to be top predators, such as jaguars.
But there are other types of food webs. For example, a detrital food web focuses on decomposers, such as fungi and soil bacteria. For the same rainforest ecosystem, the starting point for a detrital food web would be dead animals and plants.
Scientists use food webs to model the often-complicated feeding relationships between species. That can help scientists predict how changes to one species might affect other species in the ecosystem.
In a sentence
Researchers in Peru’s Amazon rainforest study opossum-eating spiders to learn about this ecosystem’s unusual food web.
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