Understanding Primary Succession and Ecosystem Dynamics
School
University of Waterloo**We aren't endorsed by this school
Course
ENVS 200
Subject
Biology
Date
Dec 9, 2024
Pages
1
Uploaded by ElderLlamaPerson567
What is primary succession -Primary succession is when a new patch of land is created or exposed for the first time. It can happen when lava cools and creates new rocks or when a glacier retreats and exposes rocks without any soil yet. Primary succession is when organisms must start from scratch. Neutral community-The neutral niche community theory explains how biodiversity reacts when species are identical. For example, similar herbivores may be considered to be equivalent and essentially neutral- meaning that they will have the same niches. Whereas herbivores that eat different plants will have differing niches from one another. Successional sequence-Annual -> herbaceous perennial -> woody shrub -> treeWhy is the world green?-Due to the top-down control on herbivores. This perspective explains that predators keep the herbivore population in check. This ultimately means that the plant populations will flourish thus, resulting in a greener landscape. Trophic cascade-When changes are made nearer to the top of the food chain, the changes will cascade downand throughout the rest of the food chain. This happens when there is an abundance of top predators and thus, affects the population of herbivores which in turn, impacts the plants or primary producers in the ecosystem. An example remains: if a predator population were to increase significantly, this by default would decrease the number of herbivores in the area. As a result, this decrease in herbivores will allow the plant population to grow and thrive- leading to increased plant biomass. To oppose this, if a top predator is removed, then the herbivore populations may increase greatly, which, in turn, will cause overgrazing and a severe decline in plant populations. Indirect effect-When one species affects another species though a third party species. Thus, imposing the complexity of interactions within a single ecosystem. An example of this would be Orcas.If the number of predatory orca whales determines the abundance of abalones, despite the fact that orcas do not prey on abalone, this would be called an indirect effect. Bottom-up control-When all trophic levels are being controlled by the abundance of resources available to plants, it is called bottom-up control. The bottom-up control theory suggests that the abundance and productivity of primary producers (plants) dictate the structure and dynamicsof the food web as a whole. Therefore, the number of plants in an ecosystem dictates and waivers over the entirety of a food chain. Climax stage-The climax stage occurs when the most efficient competitors outcompete other species. Typically, in this stage, the community reaches a stable state where the dominant species are well-enough-adapted to the environment and can effectively compete against each otherfor resources.
