Answer: energy
Step-by-step explanation:
Biodiversity can be defined as the variety or variability of species of flora and fauna in an ecosystem. A larger number of plant species or flora contributes to the greater variety of crops also some of the animal or faunal species are source of food for human beings.
The biodiversity involves the distribution of energy in the form of food in an ecosystem. This circulation is facilitated by the food chain when one organism is consumed by the other. Thus the direct ecosystem service of biodiversity is the distribution of energy among the organisms.