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Abstract
On August 24, 2009, while working in Rocky Mountain National Park (Estes Park, Colorado, USA) on the Conserving Limber Pine Genetic Diversity for Possible Future Restoration at Rocky Mountain National Park project (see Schoettle et al. 2011, 2013, in press), a crew from the U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station (RMRS) noticed a small limber pine (Pinus flexilis) with a dead top along Highway 36 near the Many Parks Curve (fig. 1). The tree was about 2 m tall and 7 to 10 cm in diameter at breast height (d.b.h., 1.37 m) and occurred at about 3,000 m in elevation. The UTM coordinates for the tree are E445370, N4471762 (WGS84, Z13N). The signs on the main stem were consistent with symptoms caused by the canker fungus Cronartium ribicola, which causes white pine blister rust (WPBR). Mature trees and seedlings in the area around the infected tree were surveyed on September 11, 2009. One branch in the upper crown of a mature tree at 3,020 m in elevation resembled WPBR because of the extensive chewing by squirrels (Family Sciuridae). The tree was flagged and its UTM coordinates are E445230, N4471698 (WGS84, Z13N). No other suspected cankers were found. Similar surveys of mature and young trees were conducted at each of 17 research sites within the eastern side of the park and no other suspected WPBR infections were observed. Ribes inerme, a susceptible alternate host for C. ribicola, is present along Hidden Valley Creek in the Beaver Ponds area, suggesting that this area could serve as a source of basidiospores to infect limber pine up slope if the rust were present in the area. No evidence of rust infection of the Ribes plants in the Beaver Ponds area was seen during a 2009 inspection.
Parent Publication
Citation
Schoettle, Anna; Goodrich, Betsy; Klutsch, Jen; Burns, Kelly. 2018. White pine blister rust confirmed on limber pine (Pinus flexilis) in Rocky Mountain National Park. In: Schoettle, Anna W.; Sniezko, Richard A.; Kliejunas, John T., eds. Proceedings of the IUFRO joint conference: Genetics of five-needle pines, rusts of forest trees, and Strobusphere; 2014 June 15-20; Fort Collins, CO. Proc. RMRS-P-76. Fort Collins, CO: U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station. p. 201-204.
