Question

why do ecologists break the various life forms into different groups or subsets of groups?
to make it easier to understand which group or subset of a group is being discussed
to make studying living things more difficult to understand
to make things more confusing when taking a course like biology or environmental science

Explanation:

Grouping life - forms simplifies study and communication in ecology.

Answer:

to make it easier to understand which group or subset of a group is being discussed