Cheatgrass has been able to invade dry,temperate grasslands and the arid,shrub-dominated habitats (sage-steppe)of North America.Which of the following is not a reason for this?
A)Cheatgrass is an annual,so there are seeds in the ground ready to grow any year.
B)Cheatgrass is somewhat fire tolerant.
C)Cheatgrass promotes fire frequency and increases fire intensity.
D)Cheatgrass competes successfully with bunchgrasses for water and nutrients.
E)All of the above are valid reasons.

Question

Quizplus · Accepted Answer

All of the above are valid reasons. Cheatgrass has adaptations that allow it to thrive in dry environments, including a short life cycle that allows it to complete its life cycle before the summer drought, and shallow roots that allow it to quickly take up available moisture. Additionally, cheatgrass is highly flammable and can create large, intense fires that remove other vegetation, creating opportunities for cheatgrass to take over. Finally, cheatgrass competes successfully with native bunchgrasses for water and nutrients, and can quickly establish dense stands that exclude other species.

Cheatgrass Has Been Able to Invade Dry,temperate Grasslands and the Arid,shrub-Dominated