Read the given paragraph and answer the following questions.

In terrestrial ecosystems, the detritus food chain (DFC) plays a pivotal role in energy flow, primarily due to the abundant presence of organic matter like dead plants and animal remains. These are decomposed by organisms, channeling substantial energy into the ecosystem. While the grazing food chain (GFC) exists, its impact is lesser in comparison to aquatic environments, where direct consumption of primary producers is common. However, pond and lake ecosystems exhibit a balance between DFC and GFC, thanks to ample sunlight and open water, promoting a significant energy flow through GFC. Rivers, though influenced by GFC from algae and plants to aquatic fauna, also see organic matter transportation. The efficiency of terrestrial decomposers and the extensive production of detritus make DFC especially vital in terrestrial ecosystems, underscoring the complex dynamics of energy transfer across different habitats.