The United States Forest Service has developed a new Forest Threat Summary Viewer highlighting each Eastern American state's exposure to "threats" to the health of their forests. Every state is assessed and their unique forest threats listed. These threat lists are the most import pests, climatic conditions, forest conversion activities and wildfire causes impacting regional environmental and economic health.

You might not be aware that there are hundreds of species of flora and fauna known to be harmful when introduced beyond their natural ranges. Many of these are exotics and have been introduced into North America from other countries. I have selected seven trees in the United States considered invasive and listed as an alien exotic pest. The one exception here is North American native black locust which becomes invasive when planting outside its natural range.

• Some Tree Invasive Exotics You Need to Know About

Forest ThreatNet Newsletter, United States Forest Service Image