Warmer and wetter might not be better

As the climate continues to change, gaps in our understanding of how the altered environment will affect forest hosts and their pathogens widen. In some areas pathogens thought to be present for centuries are changing their behaviour. Dothistroma needle blight caused by the fungus Dothistroma septosporum in northwest British Columbia (BC), Canada, is a good example. In this area both the pathogen and the host, lodgepole pine (Pinus contorta var. latifolia), are considered native species, but here Dothistroma has been responsible for killing mature host trees, which is unprecedented. A plausible link between warmer, wetter summers and directional climate change has been suggested as the primary driver. Those environmental conditions appear to be affecting the host/pathogen relationship for other diseases in the neighbouring central interior of BC including comandra blister rust (Cronartium comandrae). Disrupted host/pathogen relationships tend to favour the short-lived more adaptable pathogens rather than their long-lived hosts. These changes in forest health have not been well accounted for in fields of forest science that have been built on stability and predictability.    

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Forest health and climate change: A British Columbia perspective

The Forestry Chronicle ◽

10.5558/tfc86412-4 ◽

2010 ◽

Vol 86 (4) ◽

pp. 412-422 ◽

Cited By ~ 51

Author(s):

Alex J. Woods ◽

Don Heppner ◽

Harry H. Kope ◽

Jennifer Burleigh ◽

Lorraine Maclauchlan

Keyword(s):

Climate Change ◽

British Columbia ◽

Mountain Pine Beetle ◽

Forest Health ◽

Forest Insects ◽

Pine Beetle ◽

The World ◽

Dothistroma Needle Blight ◽

Management Recommendations ◽

Needle Blight

BC’s forests have already faced two simultaneous, globally significant, epidemics linked to climate change; the Dothistroma needle blight epidemic in NW BC and the massive mountain pine beetle epidemic throughout the BC Interior. Building on these experiences, we have compiled our best estimates of how we believe other forest health agents may behave as climate change continues to influence our forests. We have drawn on literature from around the world but have focused on the situation in BC. We have made management recommendations based on what we have seen so far and what we expect to come.Key words: climate change, forest health, forest insects, forest pathogens, forest management, British Columbia

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Worldwide Genetic Structure Elucidates the Eurasian Origin and Invasion Pathways of Dothistroma septosporum, Causal Agent of Dothistroma Needle Blight

Journal of Fungi ◽

10.3390/jof7020111 ◽

2021 ◽

Vol 7 (2) ◽

pp. 111

Author(s):

Martin S. Mullett ◽

Rein Drenkhan ◽

Kalev Adamson ◽

Piotr Boroń ◽

Anna Lenart-Boroń ◽

...

Keyword(s):

Eastern Europe ◽

Causal Agent ◽

Ancestral Population ◽

Economic Damage ◽

Invasion Pathways ◽

Western Asia ◽

Dothistroma Needle Blight ◽

Migration Pathways ◽

Dothistroma Septosporum ◽

Needle Blight

Dothistroma septosporum, the primary causal agent of Dothistroma needle blight, is one of the most significant foliar pathogens of pine worldwide. Its wide host and environmental ranges have led to its global success as a pathogen and severe economic damage to pine forests in many regions. This comprehensive global population study elucidated the historical migration pathways of the pathogen to reveal the Eurasian origin of the fungus. When over 3800 isolates were examined, three major population clusters were revealed: North America, Western Europe, and Eastern Europe, with distinct subclusters in the highly diverse Eastern European cluster. Modeling of historical scenarios using approximate Bayesian computation revealed the North American cluster was derived from an ancestral population in Eurasia. The Northeastern European subcluster was shown to be ancestral to all other European clusters and subclusters. The Turkish subcluster diverged first, followed by the Central European subcluster, then the Western European cluster, which has subsequently spread to much of the Southern Hemisphere. All clusters and subclusters contained both mating-types of the fungus, indicating the potential for sexual reproduction, although asexual reproduction remained the primary mode of reproduction. The study strongly suggests the native range of D. septosporum to be in Eastern Europe (i.e., the Baltic and Western Russia) and Western Asia.

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New data on the spread of the invasive species Dothistroma septosporum (Dorogin) M. Morelet in Belarus

Proceedings of the National Academy of Sciences of Belarus Biological Series ◽

10.29235/1029-8940-2021-66-2-147-158 ◽

2021 ◽

Vol 66 (2) ◽

pp. 147-158

Author(s):

L. A. Golovchenko ◽

N. G. Dishuk ◽

S. V. Panteleev ◽

O. Yu. Baranov

Keyword(s):

Invasive Species ◽

Molecular Genetic ◽

Botanical Garden ◽

Pine Trees ◽

The Republic ◽

Forest Nurseries ◽

Dothistroma Needle Blight ◽

Dothistroma Pini ◽

Dothistroma Septosporum ◽

Needle Blight

Red band needle blight, or Dothistroma needle blight is one of the most common and harmful diseases of pine. The causative agents of the disease are pathogenic micromycetes Dothistroma septosporum (Dorogin) M. Morelet and Dothistroma pini Hulbary. Dothistroma needle blight was firstly detected in Belarus in 2012 year, but till now information about this disease in the republic is fragmentary. The article presents the results of a survey of different pine trees, carried out in the period 2016–2020 years in botanical and dendrological gardens, forest nurseries and mini-arboretums at forestry enterprises, urban stands, nurseries of decorative plants, garden centers, for the presence of Dothistroma needle blight. The species identification of the causative agent of the disease was carried out by mycological and molecular genetic methods. In this study, Dothistroma needle blight was revealed on individual trees of Pinus mugo, P. nigra and P. ponderosa in the stands of the Central Botanical Garden of the NAS of Belarus, the dendrological garden of the Glubokoe experimental forestry enterprise, in the nurseries of decorative plants in the Grodno and Minsk regions. In the collected samples of needles, the invasive species Dothistroma septosporum was identified. The frequency of occurrence of the pathogen was 4.8–7.2 %, the proportion of observation sites in which this disease was detected at 60 %. The detection of Dothistroma needle blight on pine trees, mainly on planting material imported from abroad, indicates a transboundary route of D. septosporum entering the country. Analysis of literature data indicates the potential danger of Dothistroma needle blight for pine stands in the republic, which in turn requires the organization of regular monitoring of the disease and the development of methods to limit the spread of D. septosporum in the republic.

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Species diversity and forest health in northwest British Columbia

The Forestry Chronicle ◽

10.5558/tfc79892-5 ◽

2003 ◽

Vol 79 (5) ◽

pp. 892-897 ◽

Cited By ~ 32

Author(s):

Alex J Woods

Keyword(s):

British Columbia ◽

Species Diversity ◽

Lodgepole Pine ◽

Forest Health ◽

Root Disease ◽

Pine Plantations ◽

Thuja Plicata ◽

Interior Spruce ◽

Dothistroma Needle Blight ◽

Needle Blight

Forest management in the Interior Cedar Hemlock (ICH) zone of the Kispiox TSA in northwest British Columbia has focused on two tree species. Interior spruce (Picea engelmanni Parry ex Engelm. × Picea glauca (Moench) Voss) and lodgepole pine (Pinus contorta var. latifolia Dougl. ex Loud.) have dominated plantations, while historically, western hemlock (Tsuga heterophylla (Raf.) Sarg.), true firs (Abies lasiocarpa (Hook.) Nutt. and (Abies amabilis (Dougl. ex Loud.) Dougl. ex Forbes) and western redcedar (Thuja plicata Donn ex D. Don), have dominated the landscape. Tomentosus root disease (Inonotus tomentosus (Fr.) Teng) and Dothistroma needle blight (Mycosphaerella pini Rostr. in Munk) are the principal diseases affecting interior spruce and lodgepole pine plantations, respectively. Tomentosus root disease was found in 92% of spruce-dominated stands 100 years and older in the study area. The annual recruitment of dead interior spruce and lodgepole pine tree volume due to the disease in those stands is 4.29 m3/ha or 51 990 m3. The incidence of Tomentosus root disease in ten randomly selected spruce leading plantations aged 25–30 years ranged from 0.6% to 10.4% and averaged 5.9% of the host trees. Dothistroma needle blight was the most prevalent pest in a survey of 100 randomly selected lodgepole pine plantations and has caused considerable crop tree mortality. The disease has even caused mortality in 55-year-old lodgepole pine trees. Maintaining species diversity is essential to long-term forest health. Intensive planting of interior spruce and lodge-pole pine in this study area appears to have exacerbated disease problems. Key words: forest health, species diversity, interior spruce, lodgepole pine, Tomentosus root disease, Dothistroma needle blight

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The host spectrum of Dothistroma needle blight Mycosphaerella pini E. Rostrup – new hosts of Dothistroma needle blight observed in theCzech Republic

Journal of Forest Science ◽

10.17221/4484-jfs ◽

2012 ◽

Vol 52 (No. 1) ◽

pp. 30-36 ◽

Cited By ~ 20

Author(s):

M. Bednářová ◽

D. Palovčíková ◽

L. Jankovský

Keyword(s):

Czech Republic ◽

Pinus Ponderosa ◽

Pinus Banksiana ◽

Pinus Contorta ◽

Pinus Nigra ◽

The Czech Republic ◽

Christmas Trees ◽

Dothistroma Needle Blight ◽

Pinus Aristata ◽

Needle Blight

Dothistroma needle blight Mycosphaerella pini E. Rostrup and its anamorphic stage Dothistroma septospora (Dorog.) Morelet was detected for the first time in the territory of the Czech Republic in a consignment of imported plants of Austrian pine Pinus nigra Arnold in 1999. In 2000, it was also found on Pinus nigra in an open planting in a plantation of Christmas trees by the village of Jedovnice near Brno in South Moravia. In the Czech Republic, Dothi-stroma needle blight was identified on 13 species of pine. Pinus nigra Arnold and Pinus mugo Turra are the most frequent hosts. In addition to these species, Dothistroma needle blight was observed on Pinus ponderosa Douglas ex Lawson, Pinus jeffreyi Grev. et Balf, Pinus banksiana Lamb., Pinus contorta Douglas, Pinus rotundata Link, Pinus leucodermis Ant. and Pinus sylvestris L. Finds on Pinus aristata Engelm., Pinus rigida Mill., Pinus heldreichii H. Christ. and Pinus cembra L. var. sibirica (Du Tour) G. Don. are a certain rarity. These species are not mentioned anywhere as potential hosts of Dothistroma needle blight. As for the species of other genera Picea pungens Engelm., Picea abies L. Karst. and last but not least Picea schrenkiana Fisch. & C. A. Mey were also observed as hosts. The host range of Dothistroma needle blight recorded in papers is noted as well.

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Neotypification of Dothistroma septosporum and epitypification of D. pini, causal agents of Dothistroma needle blight of pine

Forest Pathology ◽

10.1111/efp.12304 ◽

2016 ◽

Vol 46 (5) ◽

pp. 388-407 ◽

Cited By ~ 18

Author(s):

I. Barnes ◽

A. van der Nest ◽

M. S. Mullett ◽

P. W. Crous ◽

R. Drenkhan ◽

...

Keyword(s):

Dothistroma Needle Blight ◽

Dothistroma Septosporum ◽

Needle Blight

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The outbreak history of Dothistroma needle blight: an emerging forest disease in northwestern British Columbia, Canada

Canadian Journal of Forest Research ◽

10.1139/x09-159 ◽

2009 ◽

Vol 39 (12) ◽

pp. 2505-2519 ◽

Cited By ~ 35

Author(s):

Cedar Welsh ◽

Kathy Lewis ◽

Alex Woods

Keyword(s):

British Columbia ◽

Environmental Conditions ◽

Pinus Contorta ◽

Native Forest ◽

Pine Trees ◽

Environmental Trigger ◽

History Of ◽

Current Outbreak ◽

Dothistroma Needle Blight ◽

Needle Blight

Native pathogens are normally limited in the damage they cause by host resistance and (or) environmental conditions that limit one or more phases of the disease cycle. Changes to host or environmental conditions can relax these limits and result in disease emergence. Until recently, Dothistroma needle blight (Dothistroma), caused by Dothistroma septosporum (Dorog.) Morelet, has had only minor impacts on native forest trees in western North America. Over the past decade in the forests of northwestern British Columbia, Canada, Dothistroma has caused extensive mortality in managed plantations of lodgepole pine ( Pinus contorta Dougl. ex Loud. var. latifolia Engelm.), and even mature pine trees are succumbing. We used dendrochronological techniques to reconstruct the temporal patterns of past Dothistroma outbreaks in the area using tree-ring series from sites with documented outbreaks. We found that Dothistroma outbreaks in northwest British Columbia have occurred periodically over the last 174 years, with an increase in outbreak incidence and extent since the 1940s. The most distinct change observed in the outbreak history has been the greater severity and synchrony among the sites affected during the current outbreak. A recently observed climate change trend over the study area may represent an environmental trigger that synchronized the current outbreak causing the widespread emergence of the disease.

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Is the Emergence of Dothistroma Needle Blight of Pine in France Caused by the Cryptic Species Dothistroma pini?

Phytopathology ◽

10.1094/phyto-02-11-0036 ◽

2012 ◽

Vol 102 (1) ◽

pp. 47-54 ◽

Cited By ~ 19

Author(s):

B. Fabre ◽

R. Ioos ◽

D. Piou ◽

B. Marçais

Keyword(s):

Spatial Pattern ◽

Forest Health ◽

Herbarium Specimens ◽

The Past ◽

The North ◽

Present Distribution ◽

Recent Arrival ◽

Dothistroma Needle Blight ◽

Dothistroma Pini ◽

Needle Blight

Dothistroma needle blight (DNB) emerged in France in the past 15 years. This disease is induced by two closely related species: Dothistroma septosporum and D. pini. Although both species are currently present in France, only D. septosporum was reported in the past. We investigated whether a recent arrival of D. pini in France could be a cause of the DNB emergence. We analyzed herbarium specimens of pine needles with DNB symptoms using polymerase chain reaction techniques to study the past frequency of D. pini in France. We also determined the present distribution within the country of D. septosporum and D. pini and compared it with the spatial pattern of DNB reported in the Département de la Santé des Forêts (DSF; French forest health monitoring agency) database. Although D. pini was detected on herbarium specimens from 1907 and 1965, it was not frequent in France in the past. Today, it is frequent, although not present throughout the country, being absent from the north and the east. There is no relationship between the D. pini distribution in France and the spatial pattern of DNB reported in the DSF database. Thus, the emergence of DNB in France cannot be explained by a recent arrival of D. pini.

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Effector identification in the pine pathogen Dothistroma septosporum

New Zealand Plant Protection ◽

10.30843/nzpp.2016.69.5903 ◽

2016 ◽

Vol 69 ◽

pp. 94-98

Author(s):

L. Hunziker ◽

C.H. Mesarich ◽

R.L. McDougal ◽

R.E. Bradshaw

Keyword(s):

Fungal Pathogens ◽

Host Defence ◽

In Planta ◽

Bioinformatics Pipeline ◽

Resistance Response ◽

Effector Genes ◽

Defence Responses ◽

Dothistroma Needle Blight ◽

Dothistroma Septosporum ◽

Needle Blight

Effectors are molecules produced by plantassociated organisms such as fungal pathogens that facilitate infection of specific plant hosts Some effectors directly or indirectly suppress host defence responses while others help to mask the foreign invader from recognition by the plant Plants can also recognise and respond to specific effectors to mount a resistance response Thus the study of effectors is important for an understanding of plantpathogen interactions Dothistroma septosporum causes Dothistroma needle blight (DNB) a conifer disease of worldwide importance In this study effector genes specific to the D septosporumPinus radiata interaction were identified A bioinformatics pipeline was employed to predict effector candidates on the basis of characteristics such as secretion from the fungus and expression in planta Using this pipeline 55 effector candidates for future analysis were identified

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