Table of Contents
What is a top-down trophic system?
A top-down controlled system focuses on how top consumers influence lower trophic levels. This could be thought of as a predator driven system. One of the classic examples of a top-down trophic cascade is the sea otter story from the Pacific coast. Key players in the food chain are sea otters, sea urchins and kelp.
How is a trophic cascade top-down regulation?
Trophic cascades: In top-down regulation, different trophic levels are limited by the next level up. For example, in a simple system of three trophic levels—plants, herbivores, and carnivores—plants are limited by herbivores, which are limited by predators.
What is a trophic cascade simple definition?
Trophic cascades are powerful indirect interactions that can control entire ecosystems. Trophic cascades occur when predators limit the density and/or behavior of their prey and thereby enhance survival of the next lower trophic level.
What is a top-down Cascade?
A top-down cascade is a trophic cascade where the top consumer/predator controls the primary consumer population. In turn, the primary producer population thrives. The removal of the top predator can alter the food web dynamics.
What is top-down vs bottom-up control in an ecosystem?
The bottom-up effect means that a lower trophic level in the biological network affects the community structure of higher trophic levels by means of resource restriction [12]. The top-down effect refers to a higher trophic level influences the community structure of a lower trophic level through predation [10].
What is top-down population control?
In the top-down control, the populations of the organisms lower trophic levels (bottom of the pyramid) are controlled by the organisms at the top. This approach is also called the predator-controlled food web of an ecosystem.
What is the difference between bottom-up and top-down control of marine ecosystem structure and function?
Top-down effects imply control through predation, including fishery, while bottom-up effects imply control through food abundance, often thought to be driven by climate or nutrient load.
What is top-down in ecology?
The top-down effect refers to a higher trophic level influences the community structure of a lower trophic level through predation [10].
What are the two types of trophic cascades?
Types of Trophic Cascades
- Top-Down Cascade. A top-down cascade occurs in ecosystems where the top consumer or apex predator controls population of the primary consumer (herbivore).
- Bottom-up Cascade.
- Subsidy Cascade.
What are the types of trophic cascades?
What are trophic cascades quizlet?
Trophic Cascade. A series of changes in the population sizes of organisms at different trophic levels in a food chain, occurring when predators at high trophic levels indirectly promote populations of organisms at low trophic levels by keeping species at intermediate trophic levels in check.
What are mean by bottom-up and top-down control?
Each approach can be quite simple—the top-down approach goes from the general to the specific, and the bottom-up approach begins at the specific and moves to the general. These methods are possible approaches for a wide range of endeavors, such as goal setting, budgeting, and forecasting.
What is bottom-up control ecology?
The bottom-up control is driven by the presence or absence of the producers in the ecosystem. Changes in their population will affect the population of all the species in the food web, and thus, the ecosystem. This approach is also called the resource-controlled (or food-limited) food web of an ecosystem.
What is the trophic cascade theory?
trophic cascade, an ecological phenomenon triggered by the addition or removal of top predators and involving reciprocal changes in the relative populations of predator and prey through a food chain, which often results in dramatic changes in ecosystem structure and nutrient cycling.
What is a top down Cascade Labster?
A top-down cascade describes a disturbance at the level of tertiary or quarternary predators. A Bottom-up cascade describes a disturbance of the primary producers. A wasp-waist cascade describes a disturbance in the middle of the food web.