Final answer:
Environmental ecosystems are classified into freshwater, marine, and terrestrial categories, each comprising various ecosystems specific to the organisms and habitat characteristics within them.
Step-by-step explanation:
The ecological systems model categorizes environmental ecosystems into three broad categories based on their general environmental habitat: freshwater, marine (or ocean water), and terrestrial. Within these categories, specific ecosystem types can be identified based on the particular organisms present and the characteristics of the environmental habitat. These ecosystem types play a crucial role in ecological studies as they help understand how various environmental disturbances can impact ecosystem structure and dynamics, including the flow of materials and energy transfer within food webs.