Question

a team of ecologists is studying a grassland ecosystem in a national park. the team collected data on question 2: the population sizes of three species: a common herbivore (the prairie vole), a primary predator (the the sharp decline in the american bison population after year 3 suggests that the disturbance red fox), and a keystone species, a large grazing herbivore (the american bison). the data was (drought) significantly impacted their main food source, which is typically grass. if the bison population collected over a 10 - year period and is displayed in the table below. declines further, what happens to the biomass of grasses? select the best answer
grass biomass will likely decrease immediately because bison fertilize the soil, providing nutrients for the grass.
grass biomass will remain the same because carnivores will take the place of the missing bison.
grass biomass will be eliminated due to a decrease in temperature.
grass biomass will likely increase initially but changes in plant diversity could alter the long - term structure of the grassland
question 3:
the red fox populations size and decline after the disturbance are directly limited by the maximum number of prairie voles that the environment can sustainably support. this relationship demonstrates that the red fox population is dependent on the ecosystems = for its primary food source

Explanation:

• When the American Bison population (a large - grazing herbivore) declines, there is less grazing pressure on the grasses. In the short - term, without as many bison eating the grass, the grass biomass is likely to increase initially. However, over the long - term, changes in plant diversity (due to the absence of the keystone species' grazing influence) can alter the long - term structure of the grassland.
• The first option is incorrect because bison fertilizing the soil is not the main factor here; the key is grazing pressure. The second option is wrong as carnivores (Red Foxes) do not take the place of bison in terms of grass - related ecosystem functions. The third option is incorrect as there is no indication of a temperature - related elimination of grass biomass from the given data (the disturbance is drought affecting the bison's food source, which is grass).

Answer:

Grass biomass will likely increase initially, but changes in plant diversity could alter the long - term structure of the grassland.