Why is distinction of crude density and ecological density necessary? and which one of these densities are greater?

Distinction of crude density and ecological density necessary and which one of these densities are greater is explained below in details.

Explanation:

Density measure in courses of the amount of territory possible as existence reservation is ecological density. Crude density incorporates all the property within the animal's reach whereas ecological density incorporates only that division of property that can actually be established by the species.

explanation:

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.