Snow owls prey on lemmings in their arctic habitat, and their survival is closely linked to the abundance of lemmings. In years when there are many lemmings, snowy owls may raise a dozen babies. How might a scarcity of lemmings affect the snowy owl population?

for  example, forests have higher evapotranspiration than other ecosystems,  such  as grasslands, because of their deeper roots and greater leaf area. thus forests have a net moistening effect on the atmosphere and become a moisture source for downwind ecosystems.

the answer would be..

b. sucking