Ecological pyramid arranges the individual quantity, biomass or energy of organisms at different trophic levels in the ecosystem and draws a map, which looks like a pyramid, so it is called ecological pyramid or ecological cone. It can be divided into three categories: energy pyramid, biomass pyramid and quantity pyramid. The ecological pyramid can represent the nutritional structure and energy flow process of the ecosystem. As shown in the figure, the total energy flow decreases once every trophic level, and the energy transfer rate in the step-by-step flow is generally only a few percent to 20%. When studying the energy flow of lake ecosystem, Lin Deman first found that the energy transfer rate between trophic levels is about10%. Generally speaking, the energy cone must be in the shape of a right pyramid, while the biomass cone and the quantity cone may be inverted or partially inverted.
Nutritional level: refers to the sum of all biological populations in a certain link of the food chain. Producers belong to the first trophic level, planting
Carnivores belong to the second trophic level, and the third trophic level includes all carnivores that feed on herbivores, generally an ecosystem.
The number of trophic levels is 3~5. Ecological pyramid refers to the quantitative relationship between various trophic levels, and this quantitative relationship can be based on raw materials.
Quantity unit, energy unit and individual quantity unit constitute biomass pyramid, energy pyramid and quantity pyramid respectively.
Energy pyramid: refers to the graphical representation of the energy values obtained from each trophic level in unit time from low to high.
Pyramid-shaped, called energy pyramid. The lower the nutritional level, the more energy it occupies; On the contrary, the higher the nutritional level, the higher the proportion.
The less energy there is. Therefore, the base of the energy pyramid is the largest, and it gets smaller as it goes up. The energy pyramid will never be inverted.
It can be seen from the energy pyramid that the more trophic levels there are in an ecosystem, the more energy is consumed in the process of energy flow.
Biomass pyramid: It is a pyramid based on the biomass of each trophic level. This type of pyramid is in terrestrial ecosystems.
Generally, it will not be inverted.
Biomass pyramid: a pyramid drawn on the basis of the number of organisms in each trophic level. This type of gold
The word tower is often inverted.
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