Final answer:
Essential nutrients cycle through ecosystems via biogeochemical cycles, which are vital for ecosystem sustainability and involve both biotic and abiotic components.
Step-by-step explanation:
These cycles, such as the water, carbon, and nitrogen cycles, are crucial for the sustainability of natural terrestrial ecosystems. By involving both living (biotic) and non-living (abiotic) components of ecosystems, these cycles ensure that crucial elements are always available for organisms. The cycling of nutrients is a critical aspect of ecosystem health and function, and understanding these cycles is important in efforts to mitigate human impacts like pollution and climate change.