Summary A large database of invasive forest pathogens (IFPs) was developed to investigate the patterns and determinants of invasion in Europe. Detailed taxonomic and biological information on the invasive species was combined with country‐specific data on land use, climate, and the time since invasion to identify the determinants of invasiveness, and to differentiate the class of environments which share territorial and climate features associated with a susceptibility to invasion. IFPs increased exponentially in the last four decades. Until 1919, IFPs already present moved across Europe. Then, new IFPs were introduced mainly from North America, and recently from Asia. Hybrid pathogens also appeared. Countries with a wider range of environments, higher human impact or international trade hosted more IFPs. Rainfall influenced the diffusion rates. Environmental conditions of the new and original ranges and systematic and ecological attributes affected invasiveness. Further spread of established IFPs is expected in countries that have experienced commercial isolation in the recent past. Densely populated countries with high environmental diversity may be the weakest links in attempts to prevent new arrivals. Tight coordination of actions against new arrivals is needed. Eradication seems impossible, and prevention seems the only reliable measure, although this will be difficult in the face of global mobility.

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-• We investigated the influence of Thelephora terrestris, an ectomycorrhizal fungus, on the concentration of nitrogen in needles of Pinus sylvestris L. seedlings and their mycorrhizal structure within four seasons of growth.• Seedlings were grown in four treatments: (I) inoculated + 0.030 g N, (II) inoculated + 0.045 g N, (III) non-inoculated + 0.030 g N, (IV) non-inoculated + 0.045 g N under laboratory conditions and later planted in post-agricultural land.• For inoculated treatments, statistically significant differences in N concentration of needles were observed for two-and four-year-old seedlings. The number of ectomycorrhizae and concentration of N in needles were negatively correlated. After four seasons of growth the greatest numbers of ectomycorrhizae were present on seedlings from treatment II, and the smallest on seedlings from treatment IV.• Two-year-old seedlings had been colonized by at least six different fungal taxa, i.e. Cenococcum geophilum, Hebeloma crustuliniforme, Rhizopogon sp., Suillus bovinus, Thelephora terrestris and a non-identified one. Treatments I and II were dominated by the ectomycorrhizae of T. terrestris and their number was significantly greater than in treatments III or IV. On four-year-old seedlings ectomycorrhizae of T. terrestris were dominated in all treatments, while ectomycorrhizae of Hebeloma sp. were not found.nitrogen / Scots pine / mycorrhizae / Thelephora terrestri / molecular detection Résumé -Modifications du niveau d'azote et de la structure mycorhizienne de semis de pin sylvestre inoculés par Thelephora terrestris.• L'influence du champignon ectomycorhizien Thelephora terrestris sur la concentration en azote dans les aiguilles de semis de pin sylvestre et sur la structure mycorhizienne des plants a été suivie durant quatre saisons de croissance.• Les semis ont été cultivés sous quatre traitements : (I) inoculé + 0,030 g N, (II) inoculés + 0,045 g N, (III) non inoculés + 0,030 g N, (IV) non inoculés + 0,045 g N, dans les conditions du laboratoire avant d'être plantés sur le terrain.• Dans les traitements d'inoculés, des différences significatives ont été observées dans la concentration des aiguilles en azote pour les semis de deux et quatre ans. Le nombre de mycorhizes et la concentration des aiguilles en azote étaient corrélés négativement. Après quatre saisons de croissance, le plus grand nombre de mycorhizes a été obtenu dans le traitement II et le plus petit dans le traitement IV.• Les semis de deux ans avaient été colonisés par au moins six taxons différents de champignon : Cenococcum geophilum, Hebeloma crustuliniforme, Rhizopogon sp., Suillus bovinus, Thelephora terrestris et un autre taxon indéterminé. Dans les traitements I et II, les ectomycorhizes de T. terrestris dominaient et leur nombre était plus élevé que dans les traitements III et IV. Pour les semis de quatre ans, les ectomycorhizes de T. terrestris dominaient dans tous les traitements, tandis que celles de Hebeloma sp. étaient absentes.azote / pin sylvestre / mycorhizes / Thelephora t...

The goal of the current study was to evaluate the efficiency of Norway spruce wood decomposition by the saprotrophic fungus Phlebiopsis gigantea (Fr.) Jülich (used in European forests to control root rot pathogens). We identified the following indices as reliable measures of wood decay: decay acceleration index (DAI), final decay index (FD), and decay intensity index (DI). DAI was used to assess acceleration and deceleration of spruce wood loss, FD to estimate the final wood decay, and DI to evaluate the ability of the fungus to decompose wood, taking into consideration changes in mycelial activity over time. We tested the hypothesis that the wood decay activity of any fungus can be evaluated more objectively when: i) several isolates of the tested fungus are assessed simultaneously (in this case, six P. gigantea strains registered in Europe), ii) tests are performed for at least two time points, and iii) samples vary in wood density. Allowing a three-month period for wood decomposition was inadequate for reliable assessment of the wood decay ability of P. gigantea. Conversely, six months after inoculation, the tested isolates showed significant differences in their ability to generate dry wood loss, which depended on wood density. In view of these results, the DAI, FD, and DI indices are practical tools for assessing fungal activity to predict wood loss.

The research areas were located in the Pisz Forest District, northeast Poland, in 10-year-old Scots pine (Pinus sylvestris L.) plantations, established in 2004 on a clear-cut area. Reforestation was performed without a biological treatment against root pathogens, despite the presence of Heterobasidion annosum and Armillaria ostoyae in roots and stumps of trees growing previously. The aim of this research was to evaluate how thinning and treatment with the biological control agent Rotstop influences bacterial and fungal communities within roots and stumps. Twelve months after thinning, samples were collected from five stumps in each of two seasons, autumn and spring, from stands on two types of site, one previously forested and one agricultural (20 stumps in total). Wood samples were cultured on agar media, and (i) fungi in the upper part of the stump and (ii) in roots and (iii) bacteria in roots were genetically identified. Sequences were genetically identified by comparing sequences with records held in the GenBank database. We found great differences in the frequency of both fungi and bacteria in roots: they were more frequent (i) in healthy stumps compared to stumps infected with pathogens (H. annosum and A. ostoyae), (ii) in postagricultural soil than in forest soil and (iii) after spring rather than autumn biological treatment. The introduced species Phlebiopsis gigantea was only identified in the parts of the stumps which were above ground level. The bacterium Paenibacillus pini was associated with the presence of H. annosum infecting the stumps from the roots side. In areas seriously threatened by root pathogens, biological treatment can play only a limited role. It can spread to the upper part and impede the production of fruitbodies; however, it has no impact on the development of pathogens in deeper root areas.

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Scots pine sawdust, composted bark or coarse, post-harvest woody debris from conifers had been spread over the surface of barren forest soil before planting with Scots pine. The effects of the Scots pine sawdust, composted bark or coarse, post-harvest woody debris from conifers on the abundance and diversity of culturable fungi were investigated. The amendments were aimed at increasing the soil suppressiveness toArmillariaandHeterobasidion.The classical soil-dilution method was chosen for qualitative and quantitative analyses of fungal communities in soils because of its proven reliability and consistency. The soil was inhabited by saprotrophic fungi from Ascomycota and Zygomycota, including species known to be potential antagonists ofArmillariaorH. annosum(i.e.Clonostachys + Trichodermaspp.,Penicillium commune, P. daleae,P. janczewskii) or stimulants ofArmillaria(i.e.Pseudogymnoascus roseus,Trichocladium opacum). Eleven years after treatment, the abundance and diversity of fungi, the abundance ofP. commune, and locally the abundance ofP. janczewskiiincreased, whileClonostachys + Trichodermaspp., and locally,P. daleaeandT. opacumdecreased. Amending the barren soil with organic matter does not guarantee effective, long-term suppressiveness of the sandy loam soil toArmillariaandHeterobasidion.Increased abundance of entomopathogenic and nematophagous species, 11 years after treatment, does suggest the long-term possibility of insect or nematode control in soil.

Ocena wystêpowania grzybni i owocnikówAbstract. Commercial preparations Rotstop and PgSuspension, used in Scandinavia and the United Kingdom, are EUlicensed biocontrol agents against root rot that contain isolates of the fungus Phlebiopsis gigantea. The composition of these two products differs from that of PgIBL, previously use in Poland, hence the need to verify their effectiveness under Polish site and stand conditions. Stumps were treated with the commercial products and subsequently checked after one year for the persistence of mycelia and fruiting bodies. Molecular methods were used on the mycelia present in the stumps to confirm that their genetic identity was consistent with fungal isolates from the preparations. Treatments with EU-licensed preparations gave satisfactory results -in about 70-80% of the stumps mycelia were present under the bark. Inoculation with Rotstop preparations was most effective during autumn 2008 (effectiveness of 82%), while PgSuspension application was most effective during spring 2008 (effectiveness of 77%). The development of the mycelia in pine stumps from the two preparations investigated (containing preserved dormant spores) was similar to that of preparation PgIBL (formulated from living mycelium within a growing medium), in terms of their relative effectiveness measured as the percentage of stumps supporting under-bark mycelia (which ranged between 70-90%, depending on the treatment term).