Food Web of Manuel Antonio National Park
Pictured above is a food web of the tropical rainforest ecosystem of Manuel Antonio National Park. The arrows indicate the transfer of energy between the organisms and connect all organisms that are eaten to the animals that have eaten them. Unlike a linear food chain, a food web shows all of the major plants that exist within an ecosystem, the various animals that eat those plants, and the animals that eat those animals (16b). In each ecosystem, there is a keystone species that is also very apparent in the food web. A keystone species is a species that strongly influences the health of the ecosystem. If the keystone species were to be removed from the ecosystem, other trophic levels would be greatly affected as well (17). In this particular ecosystem, the keystone species would be the red-winged grasshopper. This is because the squirrel monkey, white-nosed coati, toucan, and green iguana all dependent on this species for their source of food. On the food web, the red-winged grasshopper has the most arrows pointing to the species (signifying the energy flowing to the grasshopper) and the most arrows pointing away from the species (signifying the energy flowing from the grasshopper to another organism as it is eaten). For instance, if the red-winged grasshopper was removed from the ecosystem entirely, then the population of squirrel monkeys, white-nosed coati, toucan, and green iguana would significantly decrease due to their missing source of food. Because of the decreased number of squirrel monkeys, white-nosed coati, and toucan in the ecosystem, the jaguars would have a hard time finding a substantial amount of food as well.
Energy Pyramid
The picture above is an energy pyramid, which is a diagram that exhibits the flow of energy throughout an ecosystem (20). The arrows represent the transfer of energy through each trophic level of the pyramid. Only 10% of the energy is passed on to each organism in the next trophic level; the other 90% of energy is lost as heat (as stated in the second law of thermodynamics) or used up for survival metabolically.