Kretzschmaria Deusta Research Articles

Corrigendum to: Degradation of beech wood by Kretzschmaria deusta: its heterogeneity and influence on dynamic and static bending properties

Corrigendum to: Degradation of beech wood by <i>Kretzschmaria deusta</i>: its heterogeneity and influence on dynamic and static bending properties

Incipient decay in beech (Fagus sylvatica L.) and linden (Tilia cordata Mill.): An interspecific static and dynamic material analysis

With increasing awareness of the ecological value of trees in urban areas, there is a growing need to preserve mature specimens often colonised by wood-decay fungi. Nonetheless, cases of stem collapse or uprooting of such trees under adverse weather conditions remain a significant issue requiring further investigation. Depending on the decay type and the wood structure of the host tree, different combinations of wood-decaying fungi and host species can have varying impacts on the mechanical and vibroacoustic properties of green wood. This study compares the physical and mechanical properties of green European beech (Fagus sylvatica L.) and small-leaved linden (Tilia cordata Mill.) artificially exposed to Fomes fomentarius (L.) Fr. and Kretzschmaria deusta (Hoff.) P.M.D. Martin after different exposure periods. Mass loss (ML) caused by both fungi differed according to the wood species. A statistically significant difference between the two fungal species was observed in beech wood, but not in linden. Significant differences in the modulus of rupture (MOR) and dynamic bending modulus of elasticity (MOED) were observed among the fungus-wood combinations, also depending on the exposure time. The relationships between ML and MOR varied according to the fungal species, where at the same ML values, K. deusta caused a higher MOR loss in both wood species. Strong relationships between MOED and MOR were demonstrated for all fungus-wood combinations, without significant differences related to the decay type. The MOED is a reliable parameter for predicting MOR loss even at incipient degradation stages, irrespective of the type of decay. The presented results can lead to better prediction of the impact of fungal colonization on standing trees and improve non-destructive methods used for tree stability assessment.

Degradation of beech wood by Kretzschmaria deusta: its heterogeneity and influence on dynamic and static bending properties

Abstract Strength loss caused by fungal degradation is an important factor to be considered during tree-stability assessment. Detailed information on the relationship between static mechanical properties in relation to the heterogeneity of density and dynamic mechanical parameters of wood degraded by the soft-rot fungus Kretzschmaria deusta can improve the understanding of its decay process and the interpretation of results obtained from stress-wave-based non-destructive methods used for tree-stability assessment. This research presents density profiles of artificially inoculated samples with K. deusta and static mechanical properties of green beech wood in relation to physical parameters (density, moisture content, vibroacoustic parameters). A statistically relevant difference (p &lt; 0.01) in the variability of density distribution between degraded and intact samples was proved. Relevant correlations were proved among modulus of rupture ( M O R $MOR$ ), mass loss and variability longitudinal density distribution. A strong linear relationship between M O R $MOR$ and static modulus of elasticity ( M O E $MOE$ ) of degraded and intact specimens was presented. A strong relationship was also proved between M O R $MOR$ and dynamic parameters (dynamic modulus of elasticity ( M O E D $MOED$ ) and stress-wave velocity in longitudinal direction ( c l ${c}_{l}$ )). M O E D $MOED$ showed a stronger correlation to M O R $MOR$ than c l ${c}_{l}$ proving the importance of density in assessing strength loss through non-destructive methods.

Kretzschmaria deusta, a limiting factor for survival and safety of veteran beech trees in Trentino (Alps, Northern Italy)

The importance of veteran trees is well recognised nowadays. The sudden breakage of some of these plants in Trentino (Italy), mainly due to Kretzschmaria deusta, prompted a survey of the veteran beeches reported in this area. Visual tree assessment was carried out in 40 sites with either single trees or groups of beeches, for a total of 115 trees evaluated. Most trees showed serious defects or problems in need of management and 19 had a high level of risk of breakage because of the presence of several structural problems. The presence of K. deusta was recorded on 50.4% of the examined trees. The pathogen was also identified in the proximity of investigated trees at 29 sites. Laboratory tests confirmed the identity of K. deusta by microbiological and molecular approaches and also identified Cosmopora berkeleyana as mycoparasite on K. deusta fruiting bodies. Isolates obtained from declining trees and old stumps showed the same pattern of growth at different temperatures. The risk evaluation emphasised how the fungus could affect the survival and safety of these veteran trees; this was confirmed by the collapse of four of the investigated trees in the last years. Therefore, K. deusta, which has been considered as a facultative parasite up to now, could play a more incisive role both in the decline of old beech trees and the natural evolution of aging beech woods.

Development and degradation of a submontane forest in the Beskid Wyspowy Mountains (Polish Western Carpathians) during the Holocene

Mountain regions harbour high biodiversity; however, in numerous areas, they are strongly degraded by human activity. Our study reconstructs the development of the submontane forest belt (400 and 650 m a.s.l.) in the Beskid Wyspowy Mountains (Western Carpathians, Central Europe) affected by climate, humans, fire, and parasitic fungi during the Holocene. This forest belt is considered the most transformed by the human in the Carpathian region. Our multi-proxy study included analyses of pollen, non-pollen palynomorphs (NPPs), plant macrofossils, micro- and macrocharcoal (size fraction &gt;100 µm, analysed in contiguous sampling), geochemical, and sedimentological markers. The results revealed that Picea abies dominated on the fen subjected to study at ca. 8510–5010 cal. BP. Tilia cordata was a substantial component of the submontane forest between ca. 8510 and 2970 cal. BP and it survived a probable Kretzschmaria deusta outbreak, as well as a period of increased fire activity (ca. 6000 cal. BP). The final retreat of forests with a substantial contribution of Tilia was induced by the expansion of Abies alba, Fagus sylvatica, and partly Carpinus betulus and was preceded by the period of increased fire activity and erosion. From ca. 900 cal. BP human-induced deforestations and agricultural and pastoral activity increased. The modern presence of woodlands with Pinus sylvestris and Larix decidua, in the submontane zone in the Beskid Wyspowy Mountains, is a result of sub-recent anthropogenic afforestation on overgrazed areas. The example of the Zbludza site reveals that changes related to fire and pathogen infections, if they have low magnitudes and new competitive taxa are absent, may be reversible in a forest composed of fire-intolerant tree taxa as Tilia. Nonetheless, the widespread submontane ecosystem degradation and the introduction of alien species hamper the regeneration of forest vegetation typical of the submontane zone.

Late Holocene transformations of lower montane forest in the Beskid Wyspowy Mountains (Western Carpathians, Central Europe): a case study from Mount Mogielica

This article presents a reconstruction of Late Holocene vegetation changes within the lower montane forest zone in the Beskid Wyspowy Mountains (Western Carpathians, Central Europe). Pollen, non-pollen palynomorphs, loss on ignition, and microscopic charcoal analyses were applied to a profile collected from the deposits of the rich fen which developed in the landslide depression. The results reveal that during the period between ca. 4800 ± 70 and 4160 ± 60 cal. BP, Picea abies dominated in the local forests. Between ca. 4800 ± 70 and 4660 ± 60 cal. BP, Acer was an important component in local woodlands, which distinguishes the study site from others in the Western Carpathians. At ca. 4100 ± 60 cal. BP, forests dominated by Abies alba and Fagus sylvatica expanded. Nowadays, this type of vegetation is characteristic of the lower montane zone in the Polish Western Carpathians. This expansion was probably a consequence of environmental disturbances related to the cold and wet ‘4.2 ka BP’ event. The spread of these forests was preceded by a short episode of expansion of Tilia (Tilia cordata and/or Tilia platyphyllos) which was a very local event. The area of the Beskid Wyspowy Mountains provided suitable habitats for the occurrence of T. baccata, which has not been recorded in pollen data spanning the Middle and beginning of the Late Holocene from this mountain range. A significant increase in the percentages of Kretzschmaria deusta, a parasitic fungus, reveals that A. alba–F. sylvatica forests provided an optimal habitat for such species during the period from 4070 ± 60 to 47 cal. BP. Since ca. 2640 ± 110 cal. BP, pollen of pioneer trees, such as Pinus sylvestris and Betula, as well as human activity indicators (Cerealia type and Plantago lanceolata) have become more frequent. Nonetheless, it is highly probable that this section of deposits also includes the presence of one or more sedimentary gaps.

Draft Genome Sequence of the Wood-Degrading Ascomycete Kretzschmaria deusta DSM 104547.

ABSTRACTWe report here the draft genome of Kretzschmaria (Ustulina) deusta, an ascomycetous fungus that colonizes and substantially degrades hardwood and can infest living broad-leaved trees. The genome was assembled into 858 contigs, with a total size of 46.5 Mb, and 11,074 protein-coding genes were predicted.

Identifying environmental drivers of fungal non-pollen palynomorphs in the montane forest of the eastern Andean flank, Ecuador

AbstractSamples taken from sedimentary archives indicate that fungal non-pollen palynomorphs (NPPs) can be used to provide information on forest cover, fire regime, and depositional environment in the eastern Andean flank montane forest of Ecuador. Within the 52 samples examined, 54 fungal NPP morphotypes are reported, of which 25 were found to be previously undescribed. Examination of fungal NPPs over a gradient of forest cover (2–64%) revealed three distinct assemblages: (1) low (&lt;8%) forest cover Neurospora, IBB-16, HdV-201, OU-102, and OU-110 indicative of an open degraded landscape; (2) medium (8–32%) forest cover Cercophora-type 1, Xylariaceae, Rosellinia-type, Kretzschmaria deusta, Amphirosellinia, Sporormiella, and Glomus suggestive of a forested landscape disturbed by herbivores and soil erosion; and (3) high (32–63%) forest cover Anthostomella fuegiana, OU-5, OU-101, OU-108, and OU-120. Environmental variables for forest cover (forest pollen), available moisture (aquatic remains), regional fire regime (microcharcoal), and sediment composition (organic carbon) were found to explain ~40% of the variance in the fungal NPP data set. Fire was found to be the primary control on fungal NPP assemblage composition, with available moisture and sediment composition the next most important factors.

Corrigendum to “Population structure analysis provides insights into the infection biology and invasion strategies of Kretzschmaria deusta in trees” [Fungal Ecol. 5/6 (2012) 714–725

Corrigendum to “Population structure analysis provides insights into the infection biology and invasion strategies of Kretzschmaria deusta in trees” [Fungal Ecol. 5/6 (2012) 714–725

Effects of endophytic fungi on the ash dieback pathogen

While Hymenoscyphus fraxineus causes dieback of the European ash (Fraxinus excelsior), flowering ash (F. ornus) appears resistant to the pathogen. To date, contributions of endophytic fungi to host resistance are unknown. The following hypotheses were tested: (i) endophytic fungi enhance the resistance of F. excelsior to the pathogen; (ii) resistance of F. ornus relies on its community of endophytic fungi. Two experiments were performed. (i) The effect of exudates of ash endophytes on the germination rate of H. fraxineus ascospores was studied in vitro Isolates of abundant Fraxinus leaf endophytes, such as Venturia fraxini, Paraconiothyrium sp., Boeremia exigua, Kretzschmaria deusta and Neofabraea alba inhibited ascospore germination. (ii) Ash seedlings inoculated in a climate chamber, with fungi sporulating on the previous year's leaf litter, were exposed to natural infections by the pathogen present in the forest. Non-inoculated seedlings were used as controls. Venturia spp. dominated the inoculated endophyte 'communities'. Subsequent exposure to H. fraxineus led to infection of F. excelsior leaves by the pathogen, but no differences in health status between pre-inoculated and non-inoculated seedlings were detected. Fraxinus ornus leaves experienced a low infection rate, independent of their colonization by endophytic fungi. These results did not support either hypothesis.

Anthropogenic Transformation of the Vegetation in the Immediate Vicinity of the Settlement Complex at Poganowo (Mrągowo Lakeland, Ne Poland)

Abstract The results of pollen, non-pollen palynomorph and microcharcoal particle analyses of deposits from a small pond in north eastern Poland are presented. The study focused on human-induced vegetation changes that occurred in a close vicinity of the settlement complex at Poganowo during the Middle Ages (ca 10th-16th centuries). We distinguished three phases of human impact. First and third phases correspond to intensified settlement activity. The second phase was a period when human activity decreased and woodland regeneration took place. The high incidence of the parasitic fungus Kretzschmaria deusta in a local forest stand during the third phase was simultaneous with numerous spores of coprophilous fungi (Sordaria-type and Cercophora-type). We consider that Kretzschmaria deusta inhabited the roots and bases of tree trunks damaged by digging and grazing animals.

The ascomycete Xylaria polymorpha produces an acetyl esterase that solubilises beech wood material to release water-soluble lignin fragments

Three ascomycetous soft-rot fungi belonging to the family Xylariaceae were found to produce high levels of a p-nitrophenyl acetate-hydrolyzing activity during growth on lignocellulosic materials, i.e., wheat straw and beech wood chips. Accordingly, Kretzschmaria deusta, Morchella elata, Xylaria polymorpha were seemingly most noteworthy acetyl esterase producers and, of which, X. polymorpha (strain A35) was chosen for further studies. Induction study indicated that raw carbohydrate sources, such as beech wood, rape straw, birch wood, and wheat straw, were extremely important for acetyl esterase production. Acetyl esterase of X. polymorpha was produced in solid-state culture on wheat straw and purified by different steps of anion-exchange and size-exclusion chromatography. This purified enzyme (M W = 44 kDa and pI values of 3.5–3.6) exhibited the capability to solubilise in vitro beech wood to release water-soluble lignin fragments with molecular masses of 1–3 kDa as analyzed by high performance size exclusion chromatography.

Roman impact on the landscape near castellum Fectio, The Netherlands

Castellum Fectio was one of the largest fortifications along the Limes, the northern border of the Roman Empire. The castellum, situated 5 km southeast of Utrecht, the Netherlands, was occupied from around the start of our Era to ca. a.d. 260. It was situated along a river bend of the Rhine that was cut off from the main stream during the occupation of the Roman fort. A 6 m long sediment sequence was recovered from the infill of the residual channel and pieces of Roman wall plaster, glume bases of Triticum spelta and radiocarbon dates indicate that the sediments were deposited during the period of Roman occupation. The combined palaeoecological analyses—palynological, macrobotanical, entomological and geochemical—allow a detailed reconstruction of changing environmental conditions as a consequence of the Roman occupation. The pollen record reveals a dramatic decrease in arboreal pollen, suggesting that the Romans were involved in large-scale deforestation, transforming semi-open parkland to a landscape of meadows and agricultural fields. Non-pollen palynomorphs, botanical macrofossils and insect remains support this conclusion. The recorded mycoflora shows a shift from assemblages characterised by the tree pathogen Kretzschmaria deusta to assemblages dominated by spores of fungi associated with herbaceous plants, concurrent with the decrease in arboreal pollen. The presence of masticated bran fragments of cereals, clover remains, eggs of intestinal parasites and entomological and geochemical data in the upper part of the sequence indicates that these sediments largely consist of faeces that were dumped into the former channel. Surprisingly, seeds of salt tolerant species are encountered in the sediments of this inland site, which was situated outside the influence of the sea. Horses may have brought these seeds to Fectio in their intestinal tracts after grazing in coastal meadows.

Ascospores of the parasitic fungus Kretzschmaria deusta as rainstorm indicators during a late Holocene beech-forest phase around lake Meerfelder Maar, Germany

Discrete reddish-brown, predominantly minerogenic detrital layers along the Holocene, annually laminated sediment sequence of Lake Meerfelder Maar represent extreme runoff events. We conducted detailed microfacies analyses and a high-resolution palynological investigation, focusing on ten detrital layers throughout the Holocene. We studied triad samples taken directly under, in and above the detrital layer. Fagus sylvatica (beech) was a dominant species in the regional forest around Lake Meerfelder Maar after ca. 3,800 years ago. Three detrital layers occurring during the Fagus phase exhibit short-term maxima of ascospores of the parasitic fungus Kretzschmariadeusta. In contrast, the ascospore contents are low in the event layers deposited during the early and middle Holocene. Fagus is a vulnerable host species for Kretzschmaria deusta and the fungus is common on Fagus. Ascospores are formed on the trunk base, and under normal weather conditions, few spores appear outside the forest. We interpret the short peaks in abundance of K.deusta in the event layers as indicators for rainstorms during which material was transported from the forest floor into the lake by strong winds and stormwater runoff. The open beech forest facilitated wind transport of the ascospores. We recommend analysis of fungal spores in lake sediments because fungal records may help to identify extreme weather events, even when such events are not macroscopically visible in the sediment sequence.

Tilia forest dynamics, Kretzschmaria deusta attack, and mire hydrology as palaeoecological proxies for mid-Holocene climate reconstruction in the Kashubian Lake District (N Poland)

Pollen, non-pollen palynomorph, macrofossil, and lithological analyses of mid-Holocene deposits from a small peat bog in northern Poland provide new proxy data on vegetation dynamics and climate between c. 9500 and 4600 cal. BP. The most prominent wetter climate phases occurred between c. 9500 and 9280±160 and between c. 5000 and 4600 cal. BP while a hot and dry period between 8185±145 and 5299±195 cal. BP corresponds with the Holocene Thermal Maximum (HTM). The HTM phase has been characterized by absolute dominance of Tilia cordata and the presence of T. platyphyllos beyond its current geographical range limit and a c. 2700 yr long, high incidence of the parasite fungus Kretzschmaria deusta in the local forest stand, concurrent with a dry phase on the mire. For the HTM, we suggest mean summer temperatures at least 3°C higher than today’s values. These data are in accordance with the geographic pattern of the HTM temperature anomalies in northern Europe, including the Baltic region, which suggest a gradient of positive anomalies from north to south and from west to east. The data also illustrate the effect of climate warming on the mid-Holocene pathogen outbreak and may indicate intensive vegetative reproduction as a Tilia strategy for population survival. Summer drought was probably important for high success of K. deusta in infecting weakened Tilia trees.

DETECTION OF THE WOOD DECAY ASCOMYCETE KRETZSCHMARIA DEUSTA IN URBAN MAPLE TREES IN ITALY

In June 2008, a basal stem failure of a sycamore maple tree (Acer pseudoplatanus) occurred in Turin (Italy). The failed tree did not show any external signs of fungal disease. However, the wood at the point of stem breakage was decayed and permeated by black lines. Isolations from decayed wood samples, performed on potato dextrose agar (PDA), yielded white fungal colonies that later turned greyish-brown producing hyaline, smooth and ovate conidia (5.5-7×2.5-3.5 μm) on tufts of sparsely branched conidiophores. Using a multiplex PCR assay (Nicolotti et al., 2009), the fungal cultures were identified as Kretzschmaria deusta. The features of the decayed wood and the morphological traits of pure cultures were also consistent with this diagnosis. After this finding, 77 maple trees, comprising those adjacent to the failed tree, were surveyed and sampled using the drilling method by Guglielmo et al. (2010). Although no overt signs of K. deusta in- fection were observed, multiplex PCR identified this fungus in five trees, comprising four sycamore maples and a Norway maple (Acer platanoides). Three of these infected trees were very close to the failed one, thus suggesting a clustering of infection. Inci- dence of K. deusta was higher than that of other wood decay fun- gi detected by multiplex PCR. Although K. deusta is known as a threat for the stability of different broadleaf trees in the urban context of northern and central Europe, to our knowledge this is the first report of this pathogen in urban maple trees in Italy.

Population structure analysis provides insights into the infection biology and invasion strategies of Kretzschmaria deusta in trees

Abstract Infection biology and invasion strategies of Kretzschmaria deusta were investigated through the analysis of patterns of colonization and population diversity in three case studies, comprising different host species. Molecular analysis and isolation assays performed on stem sections at different heights indicated a prevalent heart rot mode of expansion. Random amplified microsatellites – RAMs and somatic incompatibility assays on isolates allowed detection, in one case, of a genet occupying the entire decay column and, in the other cases, of several different genets in each individual tree. Hypotheses on modes of arrival and entrance of K. deusta in trees are discussed on the basis of the distribution of genets and population genetics analyses. Significant correlation (Spearman ρ = 1.0; p

Woodland disturbance and possible land-use regimes during the Late Mesolithic in the English uplands: pollen, charcoal and non-pollen palynomorph evidence from Bluewath Beck, North York Moors, UK

Pollen, micro-charcoal and non-pollen palynomorph (NPP) data from the mid Holocene Ulmus decline and the preceding millennium have provided evidence of repeated fire disturbance of the upland woodland at Bluewath Beck Head, on the North York Moors in northeast England. Woodland disturbance coincides with the Ulmus decline, which at several similar upland sites in northern England is dated to ca. 4800 uncal b.p. (ca. 5550 cal b.p.), and so to the early Neolithic period. Two fire events occur within a cycle of disturbance and regeneration between about 6100 (ca. 6950 cal b.p.) and 5700 b.p. (ca. 6475 cal b.p.), placing them in the later stages of the Late Mesolithic hunter-gatherer occupation of the upland and near the start of the transition to early Neolithic agricultural economies. Increased Melampyrum and Corylus pollen percentages characterise the post-fire vegetation response. These disturbances probably resulted from human activity, suggesting that fire was an integral part of the Late Mesolithic ecology. The local origin of some NPPs greatly enhances the palaeoecological interpretation, showing variations in the hydrological responses to disturbance that are much less visible in the pollen record, and helping to distinguish between local and regional vegetation changes. Other NPPs indicate burning near to the site. A substantial peak in spores of the wood-rot fungus Kretzschmaria deusta across the Ulmus decline may indicate girdling and other woodland management techniques as part of Neolithic woodland farming.

What was behind the bark? – An assessment of decay among urban &lt;em&gt;Tilia&lt;/em&gt;, &lt;em&gt;Betula&lt;/em&gt; and &lt;em&gt;Acer&lt;/em&gt; trees felled as hazardous in the Helsinki City area

Old trees growing in urban environments are often felled due to symptoms of mechanical defects that could be hazardous to people and property. The decisions concerning these removals are justified by risk assessments carried out by tree care professionals. The major motivation for this study was to determine the most common profiles of potential hazard characteristics for the three most common urban tree genera in Helsinki City: Tilia, Betula and Acer, and in this way improve management practices and protection of old amenity trees. For this research, material from approximately 250 urban trees was collected in cooperation with the City of Helsinki Public Works Department during 2001 2004. From the total number of trees sampled, approximately 70% were defined as hazardous. The tree species had characteristic features as potential hazard profiles. For Tilia trees, hollowed heartwood with low fungal activity and advanced decay caused by Ganoderma lipsiense were the two most common profiles. In Betula spp., the primary reason for tree removal was usually lowered amenity value in terms of decline of the crown. Internal cracks, most often due to weak fork formation, were common causes of potential failure in Acer spp. Decay caused by Rigidoporus populinus often increased the risk of stem breakage in these Acer trees. Of the decay fungi observed, G. lipsiense was most often the reason for the increased risk of stem collapse. Other fungi that also caused extensive decay were R. populinus, Inonotus obliquus, Kretzschmaria deusta and Phellinus igniarius. The most common decay fungi in terms of incidence were Pholiota spp., but decay caused by these species did not have a high potential for causing stem breakage, because it rarely extended to the cambium. The various evaluations used in the study suggested contradictions in felling decisions based on trees displaying different stages of decay. For protection of old urban trees, it is crucial to develop monitoring methods so that tree care professionals could better analyse the rate of decay progression towards the sapwood and separate those trees with decreasing amounts of sound wood from those with decay that is restricted to the heartwood area.

A Biomolecular Method for the Detection of Wood Decay Fungi: A Focus on Tree Stability Assessment

The detection and identification of wood-rotting fungi in standing trees is crucial for the prediction of the severity and evolution of decay. In the case of very active root and butt rot fungi, an early identification method is important to establish the more appropriate failure risk classification. This work is aimed at reviewing the biomolecular methods recently developed to identify, directly from wood, some of the most important and widespread decay fungi. The whole method is based on the use of taxonspecific primers combined in five multiplex polymerase chain reactions (PCRs). Three multiplex PCRs allow identifying Armillaria, Ganoderma, Hericium, Inonotus, Laetiporus sulphureus, Perenniporia fraxinea, Phellinus, Pleurotus, Schizophyllum, Stereum, Trametes, and Ustulina deusta. The two remaining multiplex PCRs were developed for subgeneric identification of fungi belonging to Ganoderma, Inonotus, and Phellinus. In validation assays, multiplex PCRs allowed successfully detecting fungi in 83% of wood samples collected from decay-affected trees. Thus, the methods proved to be efficient and specific for the diagnosis and the early detection of decay fungi on standing trees.