Search results
Results from the WOW.Com Content Network
There are two major food chains: The primary food chain is the energy coming from autotrophs and passed on to the consumers; and the second major food chain is when carnivores eat the herbivores or decomposers that consume the autotrophic energy. [16] Consumers are broken down into primary consumers, secondary consumers and tertiary consumers.
The mean chain length of an entire web is the arithmetic average of the lengths of all chains in a food web. [42] [14] In a simple predator-prey example, a deer is one step removed from the plants it eats (chain length = 1) and a wolf that eats the deer is two steps removed from the plants (chain length = 2).
A food web starts at trophic level 1 with primary producers such as plants, can move to herbivores at level 2, carnivores at level 3 or higher, and typically finish with apex predators at level 4 or 5. The path along the chain can form either a one-way flow or a part of a wider food "web".
Ecological pyramids begin with producers on the bottom (such as plants) and proceed through the various trophic levels (such as herbivores that eat plants, then carnivores that eat flesh, then omnivores that eat both plants and flesh, and so on). The highest level is the top of the food chain. Biomass can be measured by a bomb calorimeter.
Food chain in a Swedish lake. Osprey feed on northern pike, which in turn feed on perch which eat bleak which eat crustaceans.. A food chain is a linear network of links in a food web, often starting with an autotroph (such as grass or algae), also called a producer, and typically ending at an apex predator (such as grizzly bears or killer whales), detritivore (such as earthworms and woodlice ...
Within an ecological food chain, consumers are categorized into primary consumers, secondary consumers, and tertiary consumers. [3] Primary consumers are herbivores, feeding on plants or algae. Caterpillars, insects, grasshoppers, termites and hummingbirds are all examples of primary consumers because they only eat autotrophs (plants).
The observed values of connectance in empirical food webs appear to be constrained by the variability of the physical environment, [4] by habitat type, [5] which will reflect on an organism's diet breadth driven by optimal foraging behaviour. This ultimately links the structure of these ecological networks to the behaviour of individual organisms.
Consumer–resource interactions are the core motif of ecological food chains or food webs, [1] and are an umbrella term for a variety of more specialized types of biological species interactions including prey-predator (see predation), host-parasite (see parasitism), plant-herbivore and victim-exploiter systems.