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Dutch elm disease (DED) still occurs in Poland. Previous studies confirmed occurring O. ulmi and two subspecies of O. novo-ulmi: subsp. novo-ulmi and subsp. amerciana. In this study the population of Ophiostoma occurred in Poland was investigated. The disease incidence was investigated on elms growing in 39 locations. The pathogen’s mycelium was isolated from elm branches and twigs collected from 22 plots. The disease symptoms were noted in 5% to 35% trees. Fungi were identified based on the PCR amplification of the ITS 1/2 rDNA together with phylogenetic analysis of this region. Ophiostoma novo-ulmi was the only agent caused DED on Ulmus glabra, U. minor and U. laevis. There were no genetic diversity of O. novo-ulmi Polish population in analyzed ITS region. All kind of specific symptoms and disease intensity occurred independently on elm species and host age. Ulmus minor was infested most sever among the three elms species.
In central Europe, the endangered Rosalia longicorn Rosalia alpina (L.) has rarely been observed to develop in the wood of elms Ulmus sp.; however, this beetle has recently expanded into habitats formed by elms. The factors driving these changes are unknown in detail, but a potential one is the increasing amount of breeding material, namely, dead elm wood. Dutch elm disease, caused by the fungi Ophiostoma ulmi and O. novo-ulmi, by killing off elm trees, has created a supply of dead wood. The aim of this work was to assess the potential role of Dutch elm disease in the formation of habitats suitable for the endangered Rosalia longicorn. The health of four elm stands (Carpathians, SE Poland) was analysed and the pathogen responsible for elm death were determined by DNA sequence comparison. O. novo-ulmi — the causative agent of Dutch elm disease — was isolated from weakened and dying trees at all studied localities. In total, 30% of the elm trees were dead, 34% showed signs of dieback or were moribund, while some 36% showed no signs of dieback (N = 120). The presence of the Rosalia longicorn was recorded at all four studied localities. The use of elms as a host plant was long-term; dead trees served as a breeding material through the past 11 years. Our results indicate that O. novo-ulmi is playing an important part in the death of elms in Rosalia longicorn localities. Dutch elm disease, due to its wide distribution, may shape suitable habitats for Rosalia longicorn within the species' range. While the chronic nature of the disease contributes to the slow and inexorable death of these trees, it may at the same time be a factor promoting the long-term stability of Rosalia longicorn habitats.
This is the first report on development of Rosalia alpina (LINNAEUS, 1758) (Coleoptera: Cerambycidae) in wood of elm (Ulmus L.) in Poland, on the basis of the adult beetle reared from the material collected in the Beskid Niski mountain range.
Elm resources in Poland were analysed on the basis of latest forestry inventory data (updated in 2012). As compared with the 1970s, a remarkable increase was noticed in the total area of forest stands dominated by elms. However, the contribution of elms to the total forest area in Poland is still small (17 653.67 ha, i.e. 0.24% of the total forest area), while forest stands dominated by them cover only 1011.84 hectares (0.01%). Elm forests are the most frequent at alluvial sites, but majority of elm trees is scattered in lowlands, mostly at the fertile potential sites of oak−hornbeam forest. Elms do not prefer any part of Poland, but their contribution is markedly lower in forests of the Sudety Mountains.
The aim of the study was to describe the relationships between the flowering phase of selected tree species, whose pollen is known to be allergenic, and fluctuations in the pollen in the air, and to use results obtained for making allergological forecasts. Studies were conducted of five tree taxa: Populus, Ulmus, Salix, Aesculus, and Tilia, in the years 2003-2004. Aeropalinological analyses concerned the above mentioned genera, while in phenological studies specific species were investigated, i.e. the most common representatives of a given genus found in Poland, that is Populus wilsonii, Ulmus laevis Pall. C. K.Schneid., Salix caprea L., Aesculus hippocastanum L. and Tilia cordata Mill. Aerobiological monitoring was performed using a the volumetric method and phenological observations of flowering phases were made according to the Lukasiewicz method. While observing the emergence of individual phenological symptoms and measurements of the concentration of pollen of the investigated taxa in the air of Poznań, a distinct acceleration was observed in 2004, a year that was characterized by a milder winter. This applied not only to the species blooming in early spring, but also to the later ones. Pollen grains of the investigated taxa, except for Aesculus, appeared earlier in aeropalinological observations than the macroscopically observed beginning of flowering in selected trees. Apart from a poplar, the end of flowering in the other trees occurred each year earlier than would follow from the aerobiological observations. This may be explained by the abundance of species within a taxon, and the effect of medium - and long-distance transport.
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