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That is, the consumer trophic level is one plus the weighted average of how much different trophic levels contribute to its food. In the case of marine ecosystems, the trophic level of most fish and other marine consumers takes a value between 2.0 and 5.0.
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.
For example, among aquatic ecosystems, higher rates of production are usually found in large rivers and shallow lakes than in deep lakes and clear headwater streams. [25] Among terrestrial ecosystems, marshes, swamps, and tropical rainforests have the highest primary production rates, whereas tundra and alpine ecosystems have the lowest. [25]
An ecosystem (or ecological system) is a system formed by organisms in interaction with their environment. [2]: 458 The biotic and abiotic components are linked together through nutrient cycles and energy flows. Ecosystems are controlled by external and internal factors.
Ecological units refer to specific levels or degrees of organization within ecological systems. The units that are most commonly used and discussed within ecological systems are those at the levels of individuals, populations, communities, and ecosystems. [1]
Ecological classification or ecological typology is the classification of land or water into geographical units that represent variation in one or more ecological features. . Traditional approaches focus on geology, topography, biogeography, soils, vegetation, climate conditions, living species, habitats, water resources, and sometimes also anthropic factors.
The classification system has four levels, but only Levels I and III are on this list. Level I divides North America into 15 broad ecoregions; of these, 12 lie partly or wholly within the United States. Fifty Level II regions were created to allow for a narrower delineation of Level I areas. Three level I areas were not subdivided for level 2. [2]
A diagram of energy transfer between trophic levels. Primary production occurs in autotrophic organisms of an ecosystem. Photoautotrophs such as vascular plants and algae convert energy from the sun into energy stored as carbon compounds.