Acombination of mass movements such as slump, rock slides and mudflow would be called a(n)

it's anything that aren't producers and consumers.

explanation:

you've got to be clear on what "this" is

oxygen +1 most likely

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.