Which statement about the cycling of materials through a stable ecosystem is true? Responses Certain species of bacteria are responsible for cycling nitrogen from the atmosphere to plants. Certain species of bacteria are responsible for cycling nitrogen from the atmosphere to plants. Carbon dioxide is continuously cycled through a stable ecosystem, but only bacteria can convert it to a usable form. Carbon dioxide is continuously cycled through a stable ecosystem, but only bacteria can convert it to a usable form. Radiant energy and heat are continuously recycled from animals to plants. Radiant energy and heat are continuously recycled from animals to plants. Water and energy are the only materials in an ecosystem that cannot be recycled. Water and energy are the only materials in an ecosystem that cannot be recycled.