How does a virus and viroid differ from each other?

The main difference between virus and viroids is that a virus is a small infectious agent, which can only replicate inside living cells whereas viroids are the smallest form of infectious agents, which only infect plants.

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.