The chemical compounds of plant leaves may be used to defend against rust diseases. The effect of methanolic leaf extracts from four resistant and four susceptible alternate hosts of Cronartium pini and C. ribicola, and two pure phenolic chemicals, such as chlorogenic acid and quercitrin, were tested on the germination of C. pini and C. ribicola spores. Aeciospores of these rusts were dusted on water agar amended with the leaf extracts and chemicals in three concentrations and a methanol control, and germination of the aeciospores was counted after 24h incubation. Germination of the rusts was compared between extracts and concentrations. All plant extracts tended to stimulate the germination of both rusts at 50 and 100ppm, but the highest concentration, 500 ppm, inhibited the germination of both rusts regardless of the extract. The germination of C. pini spores was inhibited strongly by extracts from Veronica chamaedrys, V. longifolia, Ribes rubrum and Impatiens glandulifera, chlorogenic acid, quercitrin and methanol, and weakly by extracts of Ribes nigrum, Melampyrum pratense, M. sylvaticum and Impatiens balsamina at 500 ppm. The growth of C. ribicola was strongly inhibited by all extracts at 500 ppm. Since the results indicate stronger inhibition by the extracts from resistant host species, more research is required to identify the active compounds for bio-based control of Cronartium rusts.

Keywords: aeciospores, alternate hosts, rust resistance, Scots pine blister rust, white-pine blister rust

   Nanoparticle pollution results from the release of nanoparticles into the environment, which are widely used in many areas today. For this reason, studies on nanoparticle pollution have gained significant momentum in recent years. However, studies on the effects of nanoparticle pollution on forest ecosystems and forest trees are restricted. The current study aimed to reveal the effects of copper oxide (CuO) nanoparticles, which are known for their high toxicity compared to other metal oxide nanoparticles, on the seed germination and seedling traits of Prunus avium. Seeds from 15 geographically diverse Turkish populations were treated with CuO nanoparticle solutions at five concentrations (200, 400, 600, 800, and 1,000 mg/L) to evaluate nanoparticle effects. Multiple growth parameters were quantified, including germination success (rate and percentage), radicle dimensions (length and thickness), and plumule elongation. The study results reveal that CuO nanoparticle applications affect all characters except the germination rate. Generally, germination and seedling traits are positively affected at low nanoparticle doses. However, with increasing doses, the parameters begin to decrease, and when using nanoparticles in high doses, a decrease is observed that can exceed 25% compared to the control group. In addition, it was found that there was a significant decline in both germination characteristics and seedling development as the dose increased after exceeding a certain dose level (400 and 600 mg/L). Significant differences were also found among seed populations. The lowest values for most parameters were recorded in the populations of Karabük/Yenice and Bolu/Mudurnu, whereas the highest ones were observed in the populations of Tekirdağ/Şarköy, Çanakkale/Lapseki, and Kocaeli/Kefken, Turkey.

Keywords: copper oxide; germination; nanoparticle pollution; Prunus avium; seedling

   Feral Pigeons (Columba liviaf. urbana), descendants of domesticated pigeons, are highly adapted to urban environments. However, comprehensive genetic studies using the mitochondrial DNA (mtDNA) of them have been scarce. This study evaluated the genetic variability and structure of Feral Pigeons from six urban locations in Spain and Lithuania, comparing them to a population of Feral Pigeons from Taiwan. Additionally, comparisons were made with domestic pigeon breeds and two Columbidae species associated with forest habitats: the Woodpigeon (Columba palumbus) and the European Turtle Dove (Streptopelia turtur). Genetic diversity was assessed using mtDNA D-loop sequences. Among the Feral Pigeons, a low level of genetic diversity was observed (Hd=0.732; π=0.00330), with 12haplotypes forming a star-like network. Asingle haplotype was shared by nearly half of the individuals, and all haplotypes identified in Taiwan were also present in European populations. No genetic differentiation was found among pigeons within the same country, but significant divergence was observed between the European and Taiwanese populations. Compared to domestic pigeon breeds, Feral Pigeons exhibited higher variability, although both groups were considerably less diverse than the Woodpigeon and European Turtle Dove. The Turtle Dove showed the highest genetic variability, likely due to its complex phylogeography and migratory patterns. Neutrality tests indicated a recent population expansion in the Woodpigeon, following a bottleneck event. Overall, the results revealed limited genetic variability in Feral Pigeons, contrasting with the greater diversity and broader genetic structure observed in wild Columbidae species analysed.

Keywords: Feral Pigeon; Woodpigeon; European Turtle Dove; mtDNA; D-loop; genetic variability; population structure

   Mires are an important part of northern and boreal landscapes. Many peatlands have been drained in Estonia either for peat extraction, forestry or agricultural purposes. The remaining mires often have drainage ditches in their peripheral area, affecting the hydrology and vegetation. The main objective of this study was to quantify the effect of drainage on the radial growth of trees growing in the mire margin and to assess if a drainage-induced change in the radial growth of Scots pines (Pinus sylvestris L.) in a bog can be used as an indicator to determine the width of a buffer zone for the preservation of the natural interior of the mire. Pines growing at different distances from the ditch were sampled by increment borer, and their radial growth was analysed. We found a time lag in the effect of drainage on tree growth towards the interior of the mire. Detecting drainage events is complicated as the effect is mixed with the climate signal which varies also with drainage intensity. Trees growing closer to the ditch were mostly negatively affected by late autumn temperatures of the previous year, while trees in the unaffected area of the mire were more affected by winter temperatures. The positive spring and summer precipitation signal intensified towards the pristine core of the mire. A significant increase in radial increment of pines was observed near the drainage ditch up to 40 metres; however, a weaker effect of drainage was still detected at a distance of 90 metres from the ditch. The drainage effect on the radial growth disappeared at a distance between 190 and 440 metres from the ditch. This indicates that the buffer zone width to protect the mire core from forest encroachment due to anthropogenic drainage should be at least 190 metres wide.

Keywords: dendroecology; climate–growth relationships; disturbance; peatland; Pinus sylvestris L.