Which of the following could qualify as a top-down control on a grassland community?
A) limitation of plant biomass by rainfall amount
B) influence of temperature on competition among plants
C) influence of soil nutrients on the abundance of grasses versus wildflowers
D) effect of grazing intensity by bison on plant species diversity
E) effect of humidity on plant growth rates

Question

Quizplus · Accepted Answer

Grazing intensity by bison can be considered a top-down control because it involves the influence of a higher trophic level (the herbivores) on the abundance and diversity of the lower trophic level (the plants). The other options describe abiotic factors or biotic interactions that could influence plant growth and competition, but they do not involve the regulation of the ecological community by a higher trophic level.

Which of the Following Could Qualify as a Top-Down Control