Pathogenicity of fungi associated with ash dieback towards Fraxinus excelsior

2017 ◽  
Vol 66 (8) ◽  
pp. 1228-1238 ◽  
Author(s):  
T. Kowalski ◽  
P. Bilański ◽  
W. Kraj
Keyword(s):  
Fraxinus Excelsior ◽  
Ash Dieback

scholarly journals Impact of Fraxinus excelsior dieback on biota of ash-associated lichen epiphytes at the landscape and community level

2019 ◽  
Vol 29 (2) ◽  
pp. 431-450 ◽  
Author(s):  
Anna Łubek ◽  
Martin Kukwa ◽  
Patryk Czortek ◽  
Bogdan Jaroszewicz
Keyword(s):  
Tree Species ◽  
Landscape Scale ◽  
Community Level ◽  
Fraxinus Excelsior ◽  
Epiphytic Lichens ◽  
Ash Dieback ◽  
Epiphytic Lichen ◽  
Alternative Hosts ◽  
Rich Diversity ◽  
Lichen Biota

Abstract The landscape-scale extinction of a tree species may have a negative impact on diversity of associated epiphytic species. We used ordination and hierarchical clustering methods to assess landscape and the community level effects of reduction in the abundance of European ash Fraxinus excelsior, caused by ash dieback, on the associated epiphytic lichen biota in Białowieża Forest (Poland)—the best preserved forest complex in Central Europe. At the landscape level ash decline impact on the biota of ash-associated epiphytic lichens was weak, due to the high diversity of tree species, which may serve as potential alternative hosts. At this level, oak and hornbeam are the most important alternative hosts, assuring the maintenance of ash-associated epiphytic lichens. Lime, alder, and hazel appeared to be less important but still may serve as substitute phorophytes to approximately 2/3 of the ash-associated lichen biota. About 90% of epiphytic biota are likely to survive on the landscape scale. However, at the community level of alder-ash floodplain forest, where ash was dominant, about 50% of ash-associated epiphytic lichen species are threatened by ash dieback. Our results highlight the importance of a spatial scale in conservation biology. Protection of large forest areas with rich diversity of phorophyte trees increases chances of survival of the associated epiphytic organisms.

scholarly journals Ash pollen allergy and aerobiology

2019 ◽  
Vol 28 (7) ◽  
pp. 289-298 ◽  
Author(s):  
Markus Gassner ◽  
Peter Schmid-Grendelmeier ◽  
Bernard Clot
Keyword(s):  
School Children ◽  
Solid Phase ◽  
Birch Pollen ◽  
Pollen Allergy ◽  
Fraxinus Excelsior ◽  
Screening Tests ◽  
Fraxinus Americana ◽  
Ash Dieback ◽  
Pollen Emission ◽  
Pollen Concentrations

Abstract Background Allergy to ash pollen is common in some parts of Europe. Sensitization is overlooked if Oleaceae pollen allergens are not included in screening tests. Methods Between 1983 and 2007, sensitization to aeroallergens was systematically investigated using serological methods in 15-year-old school children (Immuno-CAP [carrier polymer] test). Samples from 1986 and 2006 were also tested using the immuno-solid-phase allergen chip (ISAC) assay. School children with sensitizations in 1986 were retested in 2010. Airborne pollen concentrations were determined by the Swiss pollen measuring network. Results Sensitization (>0.7 kU/l) to ash pollen (Fraxinus americana t15)—16.3% (102/627)—was more frequent than to birch pollen (Betula verrucosa t3): 15.3% (96/627). ISAC assays performed in children in 1986 and 2006 revealed higher molecular seroprevalence for nOle e 1 (15%; 15/100) compared to rBet v 1 (12%; 12/100). Followed-up subjects (age, 39) showed an increase in sensitizations to ash pollen. IgE levels to pollen from indigenous ash (Fraxinus excelsior t25) were higher than to pollen from American ash (Fraxinus americana t15). Low ash pollen emission levels were recorded at all measuring sites in Switzerland every 2–4 years. The infection of ashes by Chalara fraxinea resulted in increased emission of ash pollen. Conclusion Symptoms in individuals sensitized to ash pollen vary according to the pollen count and may be masked by pollen from other trees that flower at the same time of year. Sensitization to ash/Ole e 1 can be higher than to birch/Bet v 1. The determination of IgE to common ash (Fraxinus excelsior) is more sensitive than to American ash (Fraxinus americana). Ash dieback due to Chalara appears to increase pollen emission. Allergies to ash pollen can be significantly underestimated due to a failure to (correctly) identify them; they can also be masked by other pollen families (birch). Harmful organisms such as Chalara can intensify pollen emissions at least temporarily.

scholarly journals Rising out of the ashes: additive genetic variation for susceptibility to Hymenoscyphus fraxineus in Fraxinus excelsior

2015 ◽  
Author(s):  
F. Muñoz ◽  
B. Marçais ◽  
J. Dufour ◽  
A. Dowkiw
Keyword(s):  
Genetic Variation ◽  
Fraxinus Excelsior ◽  
Narrow Sense ◽  
Narrow Sense Heritability ◽  
Ash Dieback ◽  
Family Effects ◽  
Hymenoscyphus Fraxineus ◽  
Natural Range ◽  
Spatio Temporal ◽  
Crown Dieback

AbstractSince the early 1990s, ash dieback due to the invasive ascomycete Hymenoscyphus fraxineus is threatening Fraxinus excelsior in most of its natural range. Previous studies reported significant levels of genetic variability for susceptibility in F. excelsior either in field or inoculation experiments. The present study was based on a field experiment planted in 1995, fifteen years before onset of the disease. Crown and collar status were monitored on 788 trees from 23 open-pollinated progenies originating from 3 French provenances. Susceptibility was modeled using a Bayesian approach where spatio-temporal effects were explicitly taken into account. Moderate narrow-sense heritability was found for Crown Dieback (CD, h2=0.42). This study is first to show that Collar Lesions are also heritable (h2=0.49 for prevalence and h2=0.42 for severity) and that there is significant genetic correlation (r=0.40) between the severities of both symptoms. There was no evidence for differences between Provenances. Family effects were detected, but computing Individual Breeding Values (IBV) showed that most of the genetic variation lies within families. In agreement with previous reports, early flushing correlates with better crown status. Consequences of these results in terms of management and breeding are discussed.

scholarly journals Estimating mortality rates of European ash ( Fraxinus excelsior ) under the ash dieback ( Hymenoscyphus fraxineus ) epidemic

2018 ◽  
Vol 1 (1) ◽  
pp. 48-58 ◽  
Author(s):  
Tim L. R. Coker ◽  
Jiří Rozsypálek ◽  
Anne Edwards ◽  
Tony P. Harwood ◽  
Louise Butfoy ◽  
...  
Keyword(s):  
Mortality Rates ◽  
Fraxinus Excelsior ◽  
Ash Dieback ◽  
Hymenoscyphus Fraxineus ◽  
European Ash

scholarly journals Soil pH and Organic Matter Content Affects European Ash (Fraxinus excelsior L.) Crown Defoliation and Its Impact on Understory Vegetation

Forests ◽  
2019 ◽  
Vol 11 (1) ◽  
pp. 22 ◽  
Author(s):  
Krzysztof Turczański ◽  
Paweł Rutkowski ◽  
Marcin K. Dyderski ◽  
Dorota Wrońska-Pilarek ◽  
Mirosław Nowiński
Keyword(s):  
Organic Matter ◽  
Soil Ph ◽  
Organic Matter Content ◽  
Understory Vegetation ◽  
Fraxinus Excelsior ◽  
Soil Parameters ◽  
Alkaline Soil ◽  
Ash Dieback ◽  
Crown Defoliation ◽  
European Ash

European ash (Fraxinus excelsior L.) dieback caused by the fungus Hymenoscyphus fraxineus (T. Kowalski) Baral, Queloz, and Hosoya has been affecting European forests since 1992. The disease drives severe crown defoliation, branch loss, and finally tree mortality in European ash. The environmental factors affecting the disease process are still not fully recognized. We hypothesized that the level of crown defoliation in ash, as well as its impact on understory vegetation, will differ along the pH gradient in soil. We examined 27 ash stands in western Poland. We assessed the crown defoliation of 15 dominant and co-dominant trees, soil parameters (pH and soil organic matter contents; SOM), and also recorded the understory vegetation species composition. Most moderately and severely damaged trees occurred within the plots with a high SOM content (>7.5%) and neutral to slightly alkaline soil pH (>7.0) in the A horizon. We noted significantly lower crown defoliation in mesic sites with acidic soils and lower SOM contents. The results also showed the influence of ash crown defoliation on the species functional composition. Ash dieback led to the creation of gaps, and their colonization by other species frequently found in forest sites, especially forest-edge tall herbs.

scholarly journals Rising Out of the Ashes: Additive Genetic Variation for Crown and Collar Resistance to Hymenoscyphus fraxineus in Fraxinus excelsior

2016 ◽  
Vol 106 (12) ◽  
pp. 1535-1543 ◽  
Author(s):  
Facundo Muñoz ◽  
Benoît Marçais ◽  
Jean Dufour ◽  
Arnaud Dowkiw
Keyword(s):  
Genetic Variation ◽  
Health Status ◽  
Fraxinus Excelsior ◽  
Narrow Sense ◽  
Narrow Sense Heritability ◽  
Ash Dieback ◽  
Family Effects ◽  
Hymenoscyphus Fraxineus ◽  
Natural Range ◽  
Crown Dieback

Since the early 1990s, ash dieback due to the invasive ascomycete Hymenoscyphus fraxineus is threatening Fraxinus excelsior in most of its natural range. Previous studies reported significant levels of genetic variability in susceptibility in F. excelsior either in field or inoculation experiments. The present study was based on a field experiment planted in 1995, 15 years before onset of the disease. Crown and collar status were monitored on 777 trees from 23 open-pollinated progenies originating from three French provenances. Health status was modeled using a Bayesian approach where spatiotemporal effects were explicitly taken into account. Moderate narrow-sense heritability was found for crown dieback (h2 = 0.42). This study is first to show that resistance at the collar level is also heritable (h2 = 0.49 for collar lesions prevalence and h2 = 0.42 for their severity) and that there is significant genetic correlation (r = 0.40) between the severities of crown and collar symptoms. There was no evidence for differences between provenances. Family effects were detected, but computing individual breeding values showed that most of the genetic variation lies within families. In agreement with previous reports, early flushing correlates with healthier crown. Implications of these results in disease management and breeding are discussed.

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