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Bark stripping by red deer (Cervus elaphus L.) is one of the most acute instances of damage wrought by these animals in a forest. Because of its location, bark stripping causes damage to the thickest and most valuable part of the tree trunk, which lowers the quality of the wood due to technical flaws. The research was conducted in 25 sampling sites of pine stands aged 35 years in a mixed, fresh forest habitat in south-western Poland. The study was aimed at assessing the influence of bark damage by deer on biometric parameters of pine stands (Pinus sylvestris L.). The assessment involved the diameter at breast height, height, basal area and volume of the tree stands. The results revealed a strong deer-specific pressure on the analysed pine stands. The share of bark stripped trees ranged from 65% to 96%. The number of bark damage instances (NBDI) on a given tree was found to significantly affect its diameter at breast height. The strip-damaged trees had breast height diameters lower by 23% on average, and their mean height was lower by 8.7% as compared with the trees without damage. The mean reduction in basal area increments (G1.3) of the trees was identified at 39%. In a similar way to the diameter at breast height and the basal area, the losses in tree stand volume growth caused by deer stripping were significant and oscillated at 41%.

The assessment of the surface area of all leaves from a tree crown is regarded as one of the key parameters in scaling ecophysiological processes, such as growth, carbon budget, and water management. The purpose of this study was to investigate the variation of the mass and surface area of Scots pine needles, obtained from trees growing in the same habitat conditions but at different stock densities, therefore occupying different biosocial positions. The mass of needles and the leaf area index (LAI) were determined for an even-aged 33-year-old Scots pine stand located at a fresh mixed coniferous forest site in southwest Poland (50°32′ N; 17°42′ E). The needles, collected from all the sample trees, were subjected to a biometric analysis to determine the total mass of needles from each tree, the mass of 1000 needle pairs, the number of needles per crown, and the needle length distribution. Based on the actual measurements, we derived allometric equations for finding the fresh mass (FMN) and the surface area of the needles (SN), using the diameter at breast height (DBH) as an independent variable. The relationships between the mass of the needles and the DBH were significant (p < 0.0001), and so were those between the surface area of the needles and the DBH (p < 0.001). The fresh mass of needles for the tree stands varied from 6458 kg·ha−1 to 11,102 kg·ha−1. The LAI was in the range of 3.2 to 5.4 m2·m−2. The mean value of the LAI for the Scots pine stand was 4 m2·m−2. Further studies are required and more algorithms need to be developed for the quantitative assessment of the LAI in Scots pine trees, using a larger number of sample trees with more varied biometric features.

In the last ten years, many countries around the world recorded a new disease of the Cucurbitaceae, the agent of which was P. melonis. The ability of P. melonis 502 to form intracellular mycelium in the epidermal and parenchymal tissues of roots was shown. Leading tissues (xylem and phloem) did not colonize, which indicates the impossibility of plant vessel clogging and shows the fungus’s biochemical effects on plants, which causes the process of pathogenesis. P. melonis 502 is able to develop in a wide range of pH values, while the pH-optimum is 8.5. P. melonis 502 is able to adjust the pH of the medium to the optimal value—8.5. We also showed that cellulase enzyme synthesis depends on pH. We studied the exo-, endo- and β-glucasidase activity of P. melonis 502 and found that the highest activity of cellulase enzymes was on a medium whose pH was 8.5. In the process, the total cellulolytic activity was 0.326 U mL−1, exoglucanase activity—0.539 U mL−1, endoglucanase activity—0.950 U mL−1 and β-glucosidase activity—0.795 U mL−1.

The aim of this study was the identification of the causative agent of the basal glume rot of wheat Pseudomonas syringae pv. atrofaciens from the affected weeds in wheat crops, and determination of its virulent properties. Isolation of P. syringae pv. atrofaciens from weeds of wheat crops was carried out by classical microbiological methods. To identify isolated bacteria, their morphological, cultural, biochemical, and serological properties as well as fatty acids and Random Amplification of Polymorphic DNA (RAPD)-PCR (Polymerase chain reaction) profiles with the OPA-13 primer were studied. Pathogenic properties were investigated by artificial inoculation of wheat plants and weed plants, from which bacteria were isolated. For the first time, bacteria that are virulent both for weeds and wheat were isolated from weeds growing in wheat crops. It was shown that the fatty acids profiles of the bacteria isolated from the weeds contained typical for P. syringae pv. atrofaciens fatty acids, in particular, hydroxy acids: 3-hydroxydecanoic, 2-hydroxydodecanoic, and 3-hydroxydodecanoic. RAPD-PCR profiles of the newly isolated strains were identical to those of the collection strains P. syringae pv. atrofaciens UCM B-1011 and P. syringae pv. atrofaciens UCM B-1014 and contained a dominant fragment of 700 bp. The isolated strains, according to their phenotypic and genotypic properties, were identified as P. syringae pv. atrofaciens. It was established that the causative agent of basal glume rot of wheat P. syringae pv. atrofaciens is polyphagous and capable of infecting a wide range of plants. The main control measure for cereals diseases caused by P. syringae pv. Atrofaciens—crop rotations with nonhost species, should be revised, and alternative control methods must be proposed.