Answer:
Biodiversity: An ecosystem must have a diverse range of living organisms, including plants, animals, and microorganisms, that interact and depend on one another.
Energy flow: An ecosystem must have a source of energy, such as sunlight, that is used by organisms to carry out their life processes.
Nutrient cycling: An ecosystem must have a process for cycling nutrients, such as carbon and nitrogen, that are necessary for the growth and survival of organisms.
Water: Ecosystems need a source of water to sustain life.
Climate: An ecosystem must have appropriate climate conditions, such as temperature and precipitation, that are suitable for the growth and survival of the organisms that live there.
Physical structure and soil: An ecosystem must have the appropriate physical structure, such as terrain, and soil conditions to support the growth and survival of organisms.
Interactions and feedbacks: A complex web of interactions among organisms and between organisms and their physical and chemical environments are essential for the maintenance of an ecosystem.