Search results for "Quercus robur"
showing 10 items of 26 documents
Environmental drivers interactively affect individual tree growth across temperate European forests
2019
Forecasting the growth of tree species to future environmental changes requires a better understanding of its determinants. Tree growth is known to respond to global-change drivers such as climate change or atmospheric deposition, as well as to local land-use drivers such as forest management. Yet, large geographical scale studies examining interactive growth responses to multiple global-change drivers are relatively scarce and rarely consider management effects. Here, we assessed the interactive effects of three global-change drivers (temperature, precipitation and nitrogen deposition) on individual tree growth of three study species (Quercus robur/petraea, Fagus sylvatica and Fraxinus exc…
Nest sites of a strong excavator, the Great Spotted Woodpecker Dendrocopos major, in a primeval forest
2017
In managed forests, birds that create their own breeding holes in trees have limited access to substrates in which they can excavate. Therefore, nest site use in these forests possibly reflects availability of substrates more than species preferences. We analysed data on nest sites of Great Spotted Woodpeckers Dendrocopos major collected during 1987–2013 in the strictly protected part of Białowieża National Park in East Poland. The woodpeckers excavated breeding holes in 11 tree species, but species used in individual habitats varied greatly: Alder Alnus glutinosa was almost the only species used in the riverine forest; Common Aspen Populus tremula, Common Hornbeam Carpinus betulus and Pedu…
Nest sites of Middle Spotted Woodpeckers Leiopicus medius in a primeval forest
2016
Forest management usually reduces the diversity and amount of substrates in which woodpeckers can excavate holes. In such conditions the recorded patterns of nest site selection could reflect a more reduced array of substrates than the species' nest site preferences. We analysed new data on nest sites of Middle Spotted Woodpeckers Leiopicus medius collected during 27 breeding seasons (1987–2013) in the strictly protected fragments of the Białowieża National Park in Poland. The birds could use diverse excavation substrates, of various statures, that varied in condition from living and healthy to dead and completely rotten. Middle Spotted Woodpeckers used a wide array of tree species, with li…
Fragmentation-related patterns of genetic differentiation in pedunculate oak (<i>Quercus robur</i>) at two hierarchical scales
2016
Populations at speciesâ range margins are expected to show lower genetic diversity than populations at the core of the range. Yet, long-lived, widespread tree species are expected to be resistant to genetic impoverishment, thus showing comparatively high genetic diversity within populations and low differentiation among populations. Here, we study the distribution of genetic variation in the pedunculate oak ( L.) at its range margin in Finland at two hierarchical scales using 15 microsatellite loci. At a regional scale, we compared variation within versus among three oak populations. At a landscape scale, we examined genetic structuring within one of these populations, growing on an islan…
Vegetation changes in boreo–nemoral forest stands depending on soil factors and past land use during an 80 year period of no human impact
2016
Information on the long-term changes in plant communities that occur without human interference is limited, due to insufficient studies where vegetation can be resurveyed. In 1912, a strict nature protection reserve, with non-intervention management, was established on Moricsala Island in Latvia, located in the boreo–nemoral forest zone. Prior to establishment of the nature reserve, part of the island area was used for agriculture. The island is now covered almost entirely by forest dominated by Quercus robur L. and Tilia cordata Mill. on sandy soils. Resurvey was conducted in 2011 in 17 plots in which tree layers and the understory vegetation had been described in 1930. The plots were cla…
Early response ofQuercus roburseedlings to soil compaction following germination
2018
Logging operations using heavy machinery effect changes in soil characteristics due to compaction; such conditions can negatively influence seedling development. In stands managed on the basis of close-to-nature silviculture or continuous cover forestry, successful establishment of natural regeneration after logging is important to ensure the proper functioning of a forest ecosystem, to promote soil recovery, and to prevent and mitigate land degradation processes (such as soil erosion, mudflow, waterlogging, and landslides) related to soil compaction and rutting. This work aimed to assess the early response of Quercus robur seedlings to soil compaction during the first 1.5 months after germ…
Mineral nutrients in leaves and bast of pedunculate oak (Quercus Robur L.) at different states of defoliation
1998
Abstract Adult oaks (age > 135a) with different grade of defoliation were investigated for their mineral nutrient contents in leaves and bast. In the leaves of the trees with a defoliation of more than 60 % lower concentrations of almost all nutrients were found. No differences were found between defoliation class 1 (defoliation ≤ 25 %) and defoliation class 2 (defoliation ≤ 45 %). In all defoliation classes the mineral nutrient contents are in the normal range except the contents of magnesium, which is in the range of deficiency in all defoliation classes. The mineral contents in bast showed high concentrations of cadmium, manganese zinc, and aluminum in dead trees, and in the case of cadm…
Microscopical and Mycological Investigations on Wood of Pendunculate Oak (Quercus robur L) Relative to the Occurrence of Oak Decline
1996
Summary Microscopical studies exhibited great differences between healthy and damaged pendunculate oak trees (Quercus robur L.) relative to the state of sapwood vessels and the degree of fungal infection. In the sapwood of damaged trees deposits, discolorations and early tylosis formations were found which frequently occurred in combination with fungal infections. These results lead to the assumption that the defence reaction of the trees probably induced by fungal infection changes the structure of the tree vessels to such an extent that their water transfer function is disturbed. Some fungal genera playing an important role in the discussion of the causes of oak decline could be isolated.…
Pointer years in tree-ring width and earlywood-vessel area time series of Quercus robur—Relation with climate factors near its northern distribution …
2013
Abstract For a long time, radial growth of pedunculate oak (Quercus robur) in relation to environmental factors has been studied in Central Europe. However, there is insufficient information on oak growth in the Baltic region. Climate–growth interactions have been mostly investigated by correlation/response analysis between ring width and climatic factors. Other wood anatomical proxies, and also pointer year analysis, which focuses on weather extremes, can be sources of additional information. Wood samples were taken from 40 sites across Latvia. Tree-ring width (TRW) and mean area of earlywood vessels (EVA) were measured. To assess differences in wood formation among sites, a PCA was perfor…
Phytopathogenic Bacteria Associated with Bacterioses of Common Oak (Quercus robur L.) in Ukraine
2022
Studying the biological characteristics of the causative agents of bacteriosis of the common oak (Quercus robur L.) (to highlight the links between the key factors of pathogenesis and bacterial groups) is a new and relevant area of research. This work aims to identify the species composition of phytopathogenic bacteria associated with common oak bacteriosis and to study the morphological, cultural, and biochemical properties of pathogens. To establish the general phytosanitary state of the surveyed stands, classical forest inventory and phytopathological (visual on based on typical symptoms of the disease and macroscopic) methods were used. The properties of isolated bacteria were studied u…