Forest ThreatNet

New visualization tools aid in southern pine beetle exploration

By Stephanie Worley Firley, EFETAC

Landscape views that provide beauty for human enjoyment, otherwise known as viewsheds, are important—even priceless—for many reasons. However, the tiny southern pine beetle (SPB) can quickly turn a healthy forested viewshed into a disturbing scene of dead and dying trees.

Attacks by SPB, a native pest, are common in the southeastern Piedmont and Coastal Plain. The adult beetles bore into host pines to lay eggs in winding tunnels that girdle and eventually kill the trees. SPB populations can grow rapidly and affect large areas, creating a real concern for land managers as well as tourism and recreation industries and the growing number of people who call the southeast home.

Researchers Bo Song, Roy Hedden, and Thomas Williams from Clemson University's Department of Forestry and Natural Resources and Belle W. Baruch Institute of Coastal Ecology and Forest Science know how aesthetically and economically valuable the region’s viewsheds are. Beginning in 2006, they partnered with Kier Klepzig, Southern Research Station project leader for the Insects, Diseases, and Invasive Plants unit in Pineville, LA, to study the effects on viewsheds when SPB outbreaks occur.

With support from EFETAC, researchers used aerial photos and stand inventory data from various sources to develop models of areas vulnerable to SPB attacks. “Using these data from previous research, we are able to predict the probability of the occurrence of SPB infestation, including where infestations may occur and how much damage could result to forests in the viewsheds,” says Song.

But the researchers are not stopping there. They are integrating the knowledge gained from the models into GIS and 3D visualization techniques to create animated simulations of the study area before, during, and following an SPB outbreak. “Now we can fully evaluate SPB impacts on the views and aesthetic qualities of the forested landscapes,” says Song.

Researchers are also visualizing and analyzing pine host susceptibility under different forest management scenarios. “Our goal is to identify best practices for preventing or minimizing losses from SPB,” says Song. “Land managers will benefit when they can actually see how SPB spreads over the forests and how management alternatives to control spots of SPB infestation affect the landscapes. With 3D visualization, we can demonstrate the changes in a forested landscape through time in a virtual environment.”

These visualization products will not only prove to be excellent tools for land managers; they will also be effective for communicating forest management strategies to the general public. “There has been very little previous work done looking at the social aspects of invasive insect damage, including the impacts on aesthetics and the multiple uses of forests in the South. This project has provided visually impressive and powerful portrayals of SPB and management tactics to control it,” says Klepzig. “One of the most significant aspects of this project is its potential for teaching and outreach. These visualizations will allow a variety of audiences to have a greater understanding of the issues associated with forest management and threats from invasive insects.”

Above: In 1999, before an SPB infestation, mature pure pine stands covered the study area (top image). SPB attacked and killed a large number of trees during an outbreak in 2002 (center image). In 2006, the forest was recovering. Most of the trees attacked in 2002 are gone and have been replaced by regeneration shrubs, herbs, and secondary pine sprouts (bottom image).

See SPB spot growth in 3D vivid animation here.