Food Web
A food web is a complex chart that shows the movement of energy between populations or organisms within an ecosystem. The different organisms in the chart are linked by arrows that follow the movement of energy from one to the other. The side of the arrow with the point is where the energy is going. Understood elements in almost all food webs are the presence of detritivores/decomposers that recycle energy from the top of the food chain back to the bottom and the fact that plant primary producers receive their energy from the sun. This cycle of energy is typically unbroken unless something happens that removes the decomposing body of an organism entirely from an ecosystem. (22) (52)
A keystone species is a species within an ecosystem that shows a great amount of influence over the overall structure of the ecosystem. It influences the population sizes of various other organisms and its presence can tell a researcher a great amount about the health of the ecosystem. When shown in a food web, the keystone species is generally the organism that has a large amount of energy moving to away from it. In this food web, the keystone species is the jaguar because it is a high level predator that receives energy by preying on a large amount of other species such as the agouti and three-toed sloth. If this organism was removed from the ecosystem, the populations of many other species in the ecosystem would fall out of balance. Without their main predator, the population size of the agouti, the three-toed sloth, the common basilisk, and the Paca would increase. This would cause the increased population to eat more and decrease the population size of, fruit-bearing trees, insects, and other foliage within the forest. This decrease would then eventually cause the same small mammal populations that ate them to suffer a food shortage and begin to decrease in number. The populations in the ecosystem would begin to cycle largely, making the ecosystem susceptible to high amounts of change. In terms of the food web, less energy would leave the population of organisms that the jaguar used to eat and more energy would begin to move into the same populations due to the increased population size and therefore increased consumption of food.
Energy Pyramid
This energy pyramid of the ecosystem in our park shows how energy passes from one trophic level of organisms to the next. It is assumed that there are detritivores present to recycle the energy back down to the bottom of the pyramid and that the energy for the primary producer trophic level originates from sunlight. As shown by the energy totals of each trophic level, only ten percent of the energy from one level moves to the next through predation. This means that more organisms are required in the lower trophic levels to support a smaller amount of organisms in the higher trophic levels.