Deer eat grass. what term describes the ecological relationship between deer and grass?

The deer eat grass. Its droppings, which eventually decompose into the ground, provide minerals and vitamins to the plant roots. This food is vital for it so the plant remains alive and can produce oxygen which is essential for the deer and grass is also a food source for him too.

The answer your looking for is a food chain grid. it describes how nature can support itself and survival of the fittest comes into play..