Answer:
Step-by-step explanation:
"Bottom-up" and "bottom-up" approaches are utilized in ecology to comprehend the energy flow and ecosystem regulation.
The theory that an ecosystem's abundance and energy flow are determined by the availability of resources like light, water, and nutrients is known as bottom-up. All in all, the assets accessible at the foundation of the established pecking order limit the wealth of more elevated level life forms. Changes in resources at the base of the food chain are assumed to have a direct impact on the populations of organisms that rely on them in the bottom-up approach.
In contrast, top-down theory holds that the presence and behavior of top predators control the abundance and behavior of organisms in an ecosystem. Changes in the populations of top predators will have a direct impact on the populations of lower-level organisms as a result of this strategy, which shifts control of the food chain from the top to the bottom.
In class, we talked about bottom-up and top-down forces like:
Bottom-up: In marine ecosystems, studies have demonstrated that the availability of nutrients can have an effect on the growth of phytoplankton, which in turn can have an effect on the abundance of zooplankton and fish. Iron fertilization, for instance, can boost phytoplankton growth, which in turn can support more fish and zooplankton.
Top-down: In Yellowstone National Park, the reintroduction of gray wolves resulted in a trophic cascade, in which the presence of wolves decreased the number of elk and increased the number of vegetation and other herbivores like beavers and songbirds.
Both: The case of the Chesapeake Straight shellfish populace outlines both base up and hierarchical powers. Oyster populations declined as a result of disease and overfishing, resulting in a decline in water quality as oysters lost their ability to filter water. Phytoplankton and other resources from the bottom up became harder to come by as a result of the deteriorating quality of the water, further harming the oyster population.