UI Center for Research on Invasive Species and Small Populations UI Center for Research on Invasive Species and Small Populations University of Idaho College of Natural Resources University of Idaho College of Agricultural and Life Sciences Image Map
Aug 082012

George NewcombeAssociate Professor of Forest Pathology
Ecology & Conservation Biology
Forest Resources

(208) 885-5289


Dr. George Newcombe received a BS in Plant Science from McGill University in 1983 and a PhD in Botany from the University of Guelph in 1988. George’s research encompasses plant and forest pathology, and invasion biology. Specifically, his group is interested in the roles of fungi in plant communities. Photo in Beijing, September 2007, for the International Workshop on Biological Control of Invasive Species of Forest [Photo courtesy of Yilmaz Balci, University of Maryland]. more info

CRISSP Research
  1. Diagnosis of fungi that are new to North America or to the region. In 1992, George discovered for the first time in North America the Eurasian poplar leaf rust fungus, Melampsora larici-populina (Newcombe and Chastagner 1993). Since then, he has been a regular contributor to this element of invasion biology.
  2. Research on fungi that might protect native trees from exotic pathogens. With Beccy Ganley, a former PhD student, and Richard Sniezko, a colleague in the Forest Service, George discovered that selected endophytes might protect western white pine trees from the exotic disease, white pine blister rust. George and Richard are now using the same approach to see if endophyte inoculations of outplanted seedlings could make the difference in whitebark pine restoration. George is also attempting to use endophytes to protect hybrid popular plantations.
  3. Research on fungi that might be used against invasive plants. George has been researching selected endophytes that might work against invasive plants such as spotted knapweed, meadow hawkweed, and cheatgrass.
  4. Research on genes for resistance to exotic pathogens of plants. George has been conducting research in this area since getting involved in hybrid poplar research in 1991.
CRISSP Classes

FOR 531: Invasion Biology (for graduate students)
FOR 468: Forest and Plant Pathology (for senior undergraduate students)

 August 8, 2012
Aug 072012
Spotted knapweed (Centaurea stoebe)

Spotted knapweed (Centaurea stoebe) east of Missoula, Montana. Photo courtesy of Norman E. Rees, USDA Agricultural Research Service, Bugwood.org

Title: Knapweed Project
Students: Alexey Shipunov [Postdoctoral Research Associate now at the Woods Hole Oceanographic Institution], Anil Raghavendra [PhD candidate]
Summer Intern: Maryse Crawford
Collaborators: Dr. Cort Anderson, Dr. Timothey Prather, Dr. Sanford Eigenbrode, Dr. Mark Schwarzlaender, Dr. Ray Callaway
Department: Forest Resources

Project summary

Invasiveness may be the result of ‘novel weapons’ that aid an introduced plant to outcompete evolutionarily naïve neighbours in its new range. Roots of Eurasian species of Centaurea are thought to produce allelochemicals that function as novel weapons in North America. However, a series of three experiments suggested that fungal endophytes that naturally established in seedling roots could have been confounded with novel weapons. In the first two experiments, endophtyes in roots of C. stoebe significantly reduced the biomass of naïve neighbours (i.e., Festuca idahoensis plants), compared to the effect of endophyte-free C. stoebe on F. idahoensis. For the third experiment, relative abundances of endophytes of C. stoebe in both its native and invaded ranges were determined so that representatives of the six most common haplotypes, three from each range, could be employed as root inoculants. In general, each of these endophytes again reduced the growth of naïve neighbours (i.e., Festuca idahoensis); remarkably, each also increased the growth of adapted neighbours (i.e., Festuca ovina) that were tested for the first time. Four of the six endophytes caused C. stoebe to gain a competitive advantage over its naïve neighbour that was significantly greater than the competitive advantage of endophyte-free C. stoebe over that same neighbour. Endophyte-free C. stoebe had no greater competitive advantage over F. idahoensis than it had over F. ovina. By aiding an invasive plant against F. idahoensis in a cryptic manner, endophytes could be confounded with novel weapons. However, without evidence that these endophytes are themselves native to Eurasia, it is premature to assert that they are themselves novel weapons.

For more information, email the PI: Dr. George Newcombe

 August 7, 2012