scholarly journals Whitebark Pine Prevalence and Ecological Function in Treeline Communities of the Greater Yellowstone Ecosystem, U.S.A.: Potential Disruption by White Pine Blister Rust

Forests ◽  
2018 ◽  
Vol 9 (10) ◽  
pp. 635 ◽  
Author(s):  
Aaron Wagner ◽  
Diana Tomback ◽  
Lynn Resler ◽  
Elizabeth Pansing

In the northern Rocky Mountains of the U.S. and Canada, whitebark pine (Pinus albicaulis Engelm.) is a functionally important species in treeline communities. The introduced fungal pathogen Cronartium ribicola, which causes white pine blister rust, has led to extensive whitebark pine mortality nearly rangewide. We examined four treeline communities within the Greater Yellowstone Ecosystem (GYE) to assess structure and composition, whitebark pine prevalence and functional role, differences in growing season mesoclimate among study areas, and blister rust infection incidence. We found that (1) whitebark pine frequently serves as the majority overall, solitary, and leeward tree island conifer; (2) the prevalence of different tree species in the windward position in tree islands, and thus their potential as tree island initiators, may be predicted from their relative abundance as solitary trees; and (3) white pine blister rust infection incidence ranged from 0.6% to 18.0% across study areas. White pine blister rust poses a threat to treeline development and structure and the provision of ecosystem services in the GYE. Increasing blister rust resistance in nearby subalpine whitebark pine communities through seedling planting or direct seeding projects should eventually result in higher levels of blister rust resistance in whitebark pine in treeline communities.

Forests ◽  
2019 ◽  
Vol 10 (8) ◽  
pp. 666 ◽  
Author(s):  
David P. Thoma ◽  
Erin K. Shanahan ◽  
Kathryn M. Irvine

Whitebark pine, a foundation species at tree line in the Western U.S. and Canada, has declined due to native mountain pine beetle epidemics, wildfire, and white pine blister rust. These declines are concerning for the multitude of ecosystem and human benefits provided by this species. An understanding of the climatic correlates associated with spread is needed to successfully manage impacts from forest pathogens. Since 2000 mountain pine beetles have killed 75% of the mature cone-bearing trees in the Greater Yellowstone Ecosystem, and 40.9% of monitored trees have been infected with white pine blister rust. We identified models of white pine blister rust infection which indicated that an August and September interaction between relative humidity and temperature are better predictors of white pine blister rust infection in whitebark pine than location and site characteristics in the Greater Yellowstone Ecosystem. The climate conditions conducive to white pine blister rust occur throughout the ecosystem, but larger trees in relatively warm and humid conditions were more likely to be infected between 2000 and 2018. We mapped the infection probability over the past two decades to identify coarse-scale patterns of climate conditions associated with white pine blister rust infection in whitebark pine.


2011 ◽  
Vol 60 (1-6) ◽  
pp. 113-123 ◽  
Author(s):  
A. D. Bower ◽  
S. N. Aitken

AbstractWe investigated the association of inbreeding and infection by the introduced disease white pine blister rust (caused by the fungusCronartium ribicolaJ. C. Fisch) with genetic diversity of whitebark pine (Pinus albicaulisEngelm.) by genetically comparing cohorts of different ages in natural stands. Isozyme analysis of bud tissue was used to estimate expected and observed heterozygosity (Heand Ho), and Wright’s fixation index (Fis) for three age cohorts (seedling, young, and mature), sampled from 14 sites in British Columbia, Oregon, Idaho, and Montana. Comparison of genetic diversity parameters among cohorts within a site was used to assess the extent and persistence of inbreeding with age, while comparisons of parameters among sites within a cohort were used to assess the impact of the disease on genetic diversity. Significant evidence of inbreeding (Fis>0) was found in all age cohorts. When sites were stratified by level of blister rust infection, differences in Fisand Hoamong cohorts were only significant when level of infection was low. A significant negative association was found between level of blister rust infection and Hoin the mature cohort. This suggests that when differential selection due to blister rust is weak, more heterozygous individuals may be favored; however, more homozygous individuals may have higher fitness under higher blister rust levels


Ecosphere ◽  
2016 ◽  
Vol 7 (12) ◽  
Author(s):  
Erin Shanahan ◽  
Kathryn M. Irvine ◽  
David Thoma ◽  
Siri Wilmoth ◽  
Andrew Ray ◽  
...  

1996 ◽  
Vol 72 (6) ◽  
pp. 637-638 ◽  
Author(s):  
Jean A. Bérubé

White pine seedlings were treated with triadimefon two weeks prior to natural inoculation with Cronartium ribicola and were observed for two growth seasons. During the second growth season in the greenhouse the incidence of blister rust symptoms was 70.8% for the untreated controls, whereas only 3.8% of the treated seedlings showed symptoms of blister rust. Triadimefon offers effective protection against white pine blister rust infection and would enable the production of bare root seedlings in areas prone to blister rust infection.


2009 ◽  
Vol 85 (5) ◽  
pp. 745-755 ◽  
Author(s):  
Pengxin Lu ◽  
Darren Derbowka

White pine blister rust (caused by Cronartium ribicola J.C. Fisch.) is a primary cause of poor survival and growth of eastern white pine (Pinus strobus L.) and has contributed to the species’ decline across its range. Genetic resistance to C. ribicola is generally weak in eastern white pine, possibly owing to the absence of meaningful resistance alleles. Integrating major resistance genes from Eurasian 5-needle pine species to P. strobus has been demonstrated to be effective through traditional plant breeding approaches. This paper provides a review of progress after more than half a century of breeding and testing in Ontario. Key words: Pinus strobus, white pine blister rust, genetic resistance, interspecific hybridization


Forests ◽  
2018 ◽  
Vol 9 (3) ◽  
pp. 138 ◽  
Author(s):  
Brenda Shepherd ◽  
Brad Jones ◽  
Robert Sissons ◽  
Jed Cochrane ◽  
Jane Park ◽  
...  

2000 ◽  
Vol 30 (7) ◽  
pp. 1051-1059 ◽  
Author(s):  
Elizabeth M Campbell ◽  
Joseph A Antos

A major decline in the abundance of whitebark pine (Pinus albicaulis Engelm.) has recently occurred in the United States, primarily as a result of white pine blister rust (Cronartium ribicola J.C. Fisch. ex Raben.). However, no information on the status of whitebark pine in British Columbia, Canada, was available. We sampled 54 subalpine stands in British Columbia, examining all whitebark pine trees within plots for evidence of blister rust and mountain pine beetle (Dendroctonus ponderosae Hopk.) damage. About 21% of all whitebark pine stems were dead, and blister rust was the most important agent of mortality. Of all living trees sampled, 27% had obvious blister rust infection (cankers), but actual incidence was suspected of being as high as 44% (using all evidence of blister rust). Blister rust incidence and whitebark pine mortality were significantly related to differences in stand structure and the presence of Ribes spp., but relationships with local climate and site variables were absent or weak. The lack of strong relationships with climate suggests favourable conditions for the spread of the disease throughout most of British Columbia. Very little evidence of mountain pine beetle was found. Overall, the prospects for whitebark pine in British Columbia do not appear good; a large reduction in population levels seems imminent.


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