As research indicates a role for metal nanoparticles as fungicides, the work described here addresses the influence of copper nanoparticles (CuNPs) and silver nanoparticles (AgNPs) on the growth in vitro of pathogens causing damping-off as well as wood-decay fungi; i.e., Rhizoctonia solani (2 strains), Fusarium oxysporum, F. redolens and Phytophthora cactorum, along with Fistulina hepatica, Grifola frondosa, Meripilus giganteus and Sparassis crispa. Results indicate selective anti-fungal activity of the nanoparticles as applied at concentrations of 5, 15, 25 or 35 ppm. While neither nanoparticle affected P. cactorumor S. crispa, both inhibited growth in R. solani (strain 2), F. redolens and M. giganteus. R. solani (strain 1), F. oxysporum, F. hepatica and G. frondosa only showed sensitivity to higher concentrations of AgNPs, albeit with inhibitory impact on mycelial growth greater than with CuNPs. R. solani strains differed markedly in responses to both nanoparticles. Overall, the considerable toxicity of... Comme la recherche a démontré que les nanoparticules métalliques pouvaient être utilisées comme fongicides, les travaux décrits ici portent sur l’influence des nanoparticules de cuivre (CuNPs) et d’argent (AgNPs) sur la croissance in vitro d’agents pathogènes causant la fonte des semis et la carie du bois comme Rhizoctonia solani (2 souches), Fusarium oxysporum, F. redolens et Phytophthora cactorum, avec Fistulina hepatica, Grifola frondosa, Meripilus giganteus et Sparassis crispa. Les résultats laissent voir que l’activité antifongique se manifeste à des concentrations de 5, 15, 25 ou 35 ppm. Bien qu’aucune des deux sortes de nanoparticules n’ait eu d’effet sur P. cactorum ou S. crispa, les deux ont permis de limiter la croissance chez R. solani (souche 2), chez F. redolens et M. giganteus. R. solani (souche 1), F. oxysporum, F. hepatica et G. frondosa n’ont montré de la sensibilité qu’aux concentrations les plus élevées des AgNPs même si son effet d’inhibition sur la croissance mycelienne a été supérieu...

From an economic perspective, Scots pine (Pinus sylvestris L.) is one of Europe’s most important tree species. It is characterized by its wide ecological adaptability across its natural range. This research aimed to evaluate the forest structure, productivity and especially radial growth of heterogenous pine stands in 16 research plots in the Czech Republic, Poland, Spain and Great Britain. The study assessed the tree-ring formation and its relationship to climate change for each country, using 163 dendrochronological samples. The stand volume of mature pine forest ranged between 91 and 510 m³ ha⁻¹, and the carbon sequestration in the tree biomass was 40–210 t ha⁻¹. The stands had a prevailing random distribution of trees, with a high vertical structure close to selection forests (forest stands with typical very diverse height, diameter and age structure). Spectral analyses showed a substantial decrease in fluctuations in the tree-ring index and a loss in natural growth cyclicity in the last thirty years. The results also evinced that mean air temperature was the most important factor influencing the radial growth compared to precipitation totals. Pine thrives in precipitation-stable locations, as shown by the results from Great Britain. The conclusions of this study confirm the fundamental effect of ongoing global climate change on the dynamics and growth of pine forests in Europe.

Controversies about successional dynamics of woodland communities have a long history, dating back to the classical debates between Clements and Gleason and continuing into the present. These debates have largely concerned the predictability or convergence of forest developmental trends as well as the relative importance of different mechanisms and forces driving forest succession. However, opportunities for rigorous testing of competing hypotheses are limited, mainly because plot‐based studies of forest vegetation spanning more than a decade are scarce and even fewer concern late‐successional stands. We exploit a unique long‐term dataset from mesic temperate forests of eastern Poland, spanning c. 80 years (1936–2012) in strictly protected, late‐successional woodlands assigned to seven different ‘structural types’. We use non‐metric multidimensional scaling to assess the stability of species composition over the study period. We examine the predictability of composition and change trajectories over time using Mantel statistics, and we examine the changes in distributions of dissimilarity indices to assess convergence or divergence at the examined time and spatial scales. Tree communities in Białowieża Forest have changed substantially over the last eight decades. Several species (aspen, birch, pine, oak, ash, maple and spruce) exhibited large decreases in density, while a few other species (especially hornbeam and lime) have increased in importance across a wide range of initial compositional types. Forest types recognized in earlier periods have become much less distinguishable. Metrics do not yet show clear successional convergence, mainly due to (a) decline in the previously broadly distributed spruce and (b) persistence of large individuals of intermediate, long‐lived species (even though these species lack significant regeneration). Synthesis. Late‐successional woodland communities of Białowieża Forest are clearly dynamic and do not show quasi‐equilibrial properties often assumed of old‐growth forests. Forest types previously recognized as distinct have become progressively less differentiated. Plausible explanations invoke alteration in competitive relationships due to complex changes in environment, including warming climate, N deposition, natural and human disturbance, and ungulate herbivory over 80 years. Hornbeam and lime have been favoured over spruce, pine, oak and birch, although potential successional convergence is far from complete at this time. In the absence of major disturbance, we expect future decades to show continued successional homogenization.

Given their importance as a resource for many forest organisms, tree cavities were inventoried in the managed pine forests of north-east Poland, in relation to the: 70–100, 101–130 and >130 year age-classes within the clear-cutting system. The densities at which cavities were present was found to depend on forest age, given that stands 70–100 years old were characterised by an average density of 0.62 trees ha, while forests older than 130 years reported 3.28 trees ha. Stands aged 70–100 years differed from those aged 130+ in having just 0.27 trees ha of cavity trees, as compared with 2.91 trees ha. The total volume of cavity trees in stands up to 100 years old was 0.37 mhaon average, as compared with 5.42 mha in stands over 130 years old. The cavities created by woodpeckers constituted 76% of all of those found, and included 53% excavated by great spotted woodpeckers ( L.) and 23% by black woodpeckers (L.) The proportion of cavities excavated by was highest in the youngest age class of stands. There, cavities made by constituted only 8% of the total, as compared with 31% in the oldest stands. The abundance of cavity trees thus differed along an age gradient, though in any event the availability of cavity trees appears to be too limited to provide for the needs of hole-nesting birds. Forest managers must thus take more account than hitherto of the need to protect cavity trees.–1 –1 –1 –1 3 –1 3 –1 Dendrocopos major Dryocopus martius D. major D. martius

Successful tree regeneration is a key process in ensuring forest sustainability and one of the most crucial investments made in silviculture. This study compared the effects of three reforestation methods (planting, direct seeding, and natural regeneration) and three mechanical site preparation methods (double mould-board forest plough (FP); active plough (AP); and forest mill (FM)) on biometric parameters, survival, and density of Scots pine (Pinus sylvestris L.) seedlings in the first 4 years of growth in a clear-cut area in south-eastern Poland. Planted seedlings were higher, thicker in root collar, and had higher survival rates after the fourth growing season than trees from natural regeneration and direct seeding. Site preparation methods did not affect the density of planted seedlings. After natural regeneration and direct seeding, seedling density was lower and less homogeneous (plots with no seedlings) in FM soil preparation in comparison to other methods. The survival of pines in all reforestation methods was not affected significantly by site preparation methods. Our results indicate that the best mechanical site preparation method for planting is FM, as this is the one that least disturbs the soil environment. For direct seeding the best results were achieved after AP preparation. Natural regeneration of Scots pine was most effective after FP use, and in relatively wet years also after AP use.