Invasive, non-native insects and diseases are arguably the most significant threat to American trees and forests. These invasive organisms enter the country primarily via two pathways: on live plant imports—currently some 2.5 billion plants per year—and on solid wood packaging such as shipping pallets and crates.

The threat invasive species pose to forests increases as native trees cope with the effects of climate change and other factors.

Because native trees have not had the opportunity to evolve resistance to these invaders, invasive species can wipe out entire tree species and can lead to increased risks of wildfire, poor water quality and habitat loss for wildlife.

The forest products industry, nursery industry, conservation organizations, state and federal agencies, universities—all are justifiably concerned that invasive insects and diseases are degrading the economic, recreational and environmental values of forests.

Forest Health Program

With lead support from the Grantham Environmental Trust, The Nature Conservancy established the Forest Health Program in 2006 to tackle the threats posed by invasive forest insects and disease to North American forests. (Other Nature Conservancy programs address two additional large-scale threats to forest health: altered fire regimes and global climate change.)  The Grantham Challenge invites all those with a stake in the health and well-being of our forests to help advance emerging strategies that abate the threat posed by invasive organisms.

There are five approaches to our work:

• Supporting research and tools to document the extent of damage to and the value of forests
  
  
• Encouraging voluntary incentives for key industries to self-regulate
  
  
• Promoting legislative action to prevent, detect and control invasive species
  
  
• Raising public awareness of the economic and other losses incurred by invasive insects and disease
  
  
• Mobilizing collaborative action among municipalities, state agencies, environmental organizations, forest-products companies and agricultural and horticultural interests. The vehicle for collaboration is the Continental Dialogue on Non-Native Insects and Diseases.

Nature picture credits (top to bottom, left to right): Photo © Mark Godfrey (Alerce trees destroyed by human-caused fire).