7.02.09 - Phytophthora diseases on forest trees



Hot off the press: A framework to evaluate climate effects on forest tree diseases

Hennon, PE, Frankel, SJ, Woods, AJ, et al. A framework to evaluate climate effects on forest tree diseases. Forest Pathology. 2020; 00:e12649. https://onlinelibrary.wiley.com/doi/abs/10.1111/efp.12649 
A conceptual framework for evaluation of climate effects on tree diseases is presented. Climate can exacerbate tree diseases by favouring pathogen biology, including reproduction and infection processes. Climatic conditions can also cause abiotic disease—direct stress or mortality when trees’ physiological limits are exceeded. When stress is sublethal, weakened trees may subsequently be killed by secondary organisms. To demonstrate climate's involvement in disease, associations between climatic conditions and disease expression provide the primary evidence of atmospheric involvement because experimentation is often impractical for mature trees. This framework tests spatial and temporal relationships of climate and disease at several scales to document climate effects, if any. The presence and absence of the disease can be contrasted with climate data and models at geographic scales: stand, regional and species range. Temporal variation in weather, climate and climate change is examined during onset, development and remission of the disease. Predisposing factors such as site and stand conditions can modify the climate effects of some diseases, especially at finer spatial scales. Spatially explicit climate models that display temperature and precipitation or derivative models such as snow and drought stress provide useful data, and however, information on disease extent at different spatial scales and monitoring through time are often incomplete. The framework can be used to overcome limitations in other disease causality approaches, such as Koch's postulates, and allow for the integration of vegetation, pathogen and environmental data into causality determinations.
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Giles Hardy, Australia


Susan Frankel, United States

Matteo Garbelotto, United States

Thomas Jung, Czech Republic

Andrea Vannini, Italy

State of Knowledge

Knowlegde of the field is summarized in the proceedings of previous meetings of the Units:

  • 2007 MONTEREY, USA
    Proceedings: Goheen, E.M.; Frankel, S.J., tech. coords. 2009.  Phytophthoras in Forests and Natural Ecosystems. Proceedings of the Fourth Meeting of the International Union of Forest Research Organizations (IUFRO) Working Party 07.02.09. August 26-31, 2007, Monterey, CA.  Gen. Tech. Rep. PSW-GTR-221. Albany, CA: U.S. Department of Agriculture, Forest Service, Pacific Southwest Research Station. 334 p.
    Progress in Research on Phytophthora Diseases of Forest Trees, Tree Health Division, Forest Research, Alice Holt Lodge, Farnham, Surrey, GU10 4LH, UK
    Phytophthora Diseases of Forest Trees. Proceedings of the "First International Meeting on Phytophthora's in Forest and Wildland Ecosystems" (Hansen, EM and Sutton, W, eds) 30th Aug. - 3rd Sept. 1999, Grants Pass, Oregon. Proceedings

Activities and events Unit 7.02.09

Upcoming event

7th IUFRO International Workshop on the Genetics of Tree-Parasite Interactions in Forestry Understanding forest tree-antagonistic interactions in a changing worldPontevedra, Galicia, Spain

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Calendar of Meetings