How do human impacts affect these ecosystems' ability to provide provisioning services?

and after water is usually warmed by the sun the water temperature raises and then evaporates .

the answer is true when observing or determining population size, a direct observation is use, in which each organism is counted in a population or in an area. one benefit of this measure is that you get the exact population count but it will take a long time to  determine  the  size  of a  population.