Just two years ago researchers discovered that a sudden decline in black walnut in Colorado was due to a combination of the walnut twig beetle and a fungus that infested the trees by hundreds of thousands, causing cankers and cutting off the flow of nutrients. According to a University of Colorado professor, "based on the patterns seen in the West, such a colonization could very possibly develop into an uncontrollable outbreak. This may ultimately have the potential to destroy black walnut in its native range."

MORE: Kansas, a gateway to the hardwood forests that extend from the Plains to the Atlantic Ocean, has issued a state quarantine to try and protect its more than 26 million black walnut trees.