Build a trophic pyramid for three ecosytems: alpine, rainforest and river. Drag the food web component (top) and place it in the trophic pyramid (center). Each trophic level (row) must contain the same values. For example, all abiotic factors of the rainforest ecosystem must be a value of 7. To complete each of the three ecosystems, the eco-factor must equal 100 for each ecosystem. To complete each of the three puzzles, use algebra to figure out which components fit in each ecosystem. When you click on each component, a clue will be provided at the bottom. Login for your best time to be saved. The timer will reset after each ecosystem is complete.

Use the following equation to solve for the missing values:

(1  x carnivore) + (2 x herbivore) + (3 x producer) + (4 x abiotic factor) = 100


Trophic pyramidAll ecosystems are based upon the abiotic characteristics of the landscape and climate. The combined topography, soil type, amount of precipitation, amount of sunlight, temperature regime, and wind regime all affect what kind of life will grow in a particular area.

Out of these abiotic factors emerge the first level of life—the producers. As a group, producers make up what ecologists refer to as the first trophic level. Producers are the algae, cyanobacteria, and plants within an ecosystem. They produce the foods on which the other trophic levels feed. Trophic levels are simply a way for ecologists to describe the food chain. It is important to note that trophic levels are visualized as pyramidal in shape. Because energy is lost in the form of heat at each level, the quantity of life that can be supported becomes smaller at each level. All biological factors decrease at each ascending level: energy, biomass, and number of organisms.

Biological systems are typically composed of four trophic levels:

primary producers - primary consumers - secondary consumers - tertiary consumers
plants and algae herbivores small carnivores large carnivores

There are animals that overlap these groupings, such as scavengers and omnivores.

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Photo credits: Adamantios, USFWS, NPS

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