There is growing scientific evidence that there is a great deal of biological carbon that's actually stored in intact ecosystems. For example, the boreal forest is one of the largest storehouses of biological carbon in the world.
The wonderful thing is that when you conserve these ecosystems in their healthy state, you are also helping to ensure that biological carbon stays stored and is maintained in that state. It's a great co-benefit of conserving biodiversity or habitat. Wetlands and boreal forest are incredibly carbon-rich environments. By conserving them, you're also avoiding some significant emissions of carbon.