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The trophic level of an organism is the number of steps it is from the start of the chain. 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 ...
A pyramid of biomass shows the relationship between biomass and trophic level by quantifying the biomass present at each trophic level of an ecological community at a particular time. It is a graphical representation of biomass (total amount of living or organic matter in an ecosystem) present in unit area in different trophic levels.
An ecological pyramid is a graphical representation that shows, for a given ecosystem, the relationship between biomass or biological productivity and trophic levels. A biomass pyramid shows the amount of biomass at each trophic level. A productivity pyramid shows the production or turn-over in biomass at each trophic level.
A four level trophic pyramid sitting on a layer of soil and its community of decomposers. A three layer trophic pyramid linked to the biomass and energy flow concepts. In a pyramid of numbers, the number of consumers at each level decreases significantly, so that a single top consumer , (e.g., a polar bear or a human ), will be supported by a ...
A trophic pyramid (a) and a food-web (b) illustrating ecological relationships among creatures that are typical of a northern boreal terrestrial ecosystem. The trophic pyramid roughly represents the biomass (usually measured as total dry-weight) at each level. Plants generally have the greatest biomass.
Trophic cascades are powerful indirect interactions that can control entire ecosystems, occurring when a trophic level in a food web is suppressed. For example, a top-down cascade will occur if predators are effective enough in predation to reduce the abundance, or alter the behavior of their prey, thereby releasing the next lower trophic level from predation (or herbivory if the intermediate ...
trophic cascade trophic level The position of an organism within a food chain: what it eats, and what eats it. tropics tropical rain forest A biome characterized by regular, heavy rainfall, a humidity of at least 80 percent, and great biodiversity. tundra A permanently frozen, treeless expanse between the ice cap and tree line of arctic regions.
Amazon River rain forest in Peru. Tropical rainforests are hot and wet. Mean monthly temperatures exceed 18 °C (64 °F) during all months of the year. [4] Average annual rainfall is no less than 1,680 mm (66 in) and can exceed 10 m (390 in) although it typically lies between 1,750 mm (69 in) and 3,000 mm (120 in). [5]