What feature do cave ecosystems commonly depend on?

Cave ecosystems primarily depend on water sources as a fundamental feature. Water is essential for sustaining the various forms of life that inhabit these dark environments. It serves as a critical resource for not only the organisms themselves but also for the nutrients and minerals dissolved within it, which are vital for the food webs present in cave systems.

In many cave ecosystems, water often brings with it organic materials from the surface, which may include decaying plant and animal matter, providing sustenance for organisms such as bacteria, which can form the base of the food chain. Additionally, some cave-dwelling species have adapted to specific water conditions, showcasing the importance of these hydrological connections in maintaining the delicate balance of cave ecosystems.

While light, soil layers, and mineral wealth play roles in various ecological systems, they are not integral to the functioning of cave ecosystems. Caves typically do not receive light from above ground, which limits photosynthetic life, and the presence of soil layers is often minimal or absent in these subterranean environments. While minerals can be plentiful in caves, they are not a primary dependency for the organisms inhabiting them. Thus, the role of water as a foundational component in cave ecosystems distinguishes it as the correct answer.