"Because by definition we are here to protect natural systems."

The two found they shared a strong interest in the relationship between human and natural systems.

Such descriptions may include their effect on, or within, a given natural system.

The sea has no natural system of water flowing in and out.

"And you know hurricanes are part of the natural system here."

This can help in understanding the effects of climate change on complex natural systems.

Good values of for natural systems range from 0.45 to 0.75.

They may have a bad effect on the economy or even big natural systems like the Earth itself.

But the natural system was not without its own problems.

For natural systems, those data are very difficult to collect.