115,011 research outputs found
Variation in performance of beech saplings of 7 European provenances under shade and full light conditions
No full textThe use of beech seedlings from South-East European and North-West (NW) provenances for underplanting in coniferous forests in North-West Europe was investigated by means of experimental shading. The effects of this treatment on survival, morphology, phenology, physiology and growth were analysed by applying an individual plant growth model integrating these aspects. It was concluded that plant performance under full-light conditions are representative of shaded conditions, so good performing provenances can be selected in a field situation. It was further concluded that good performing South-East European seedlings can be used in North-West European conditions. The modelling results indicated an interesting trade-off between height growth and biomass increase and different provenances show different strategies. This allows selection of suitable provenances for specific situations, e.g. when beech seedlings need to compete with other plant species in the understorey
Crown plasticity and neighborhood interactions of European beech (Fagus sylvatica L.) in an old-growth forest
No full textCompetition for canopy space is a process of major importance in forest dynamics. Although virgin and old-growth European beech (Fagus sylvatica L.) forests in Europe have been studied for many years, there are to date no studies of individual-tree crown plasticity and the way this is influenced by local neighborhood interactions in these forests. In this study, we analyzed crown plasticity and local neighborhood interactions of individual trees in the upper canopy of the old-growth beech forests of Serrahn, northeast Germany. In a 2.8-ha sample plot, we measured crown radii of all upper canopy trees and analyzed the direction and extent of crown asymmetry. Size, relative position, and distance of neighboring trees were used to construct vectors of neighborhood asymmetry within different distances from target trees. The crowns of beech trees showed strong morphological plasticity. Mean absolute and relative displacement of crown centers from the stem base were 1.95 m and 0.37, respectively. Circular–circular rank correlation coefficients between the direction of crown displacement and the direction of neighborhood pressure showed that trees strongly positioned their crowns away from local neighbors. Highest correlation coefficients were obtained when basal area and relative position of neighboring trees within a radial distance of 12 m were considered. Clark and Evans index and Ripley’s K-function showed that crowns were more regularly distributed than stems. Projected canopy cover was about 10% higher than canopy cover with simulated circular crowns. We conclude that the crowns of older beech trees have a high ability to plastically respond to changes in the local canopy conditions, enabling very effective exploitation of canopy space
Climate sensitivity of radial growth in European beech (Fagus sylvatica L.) at different aspects in southwestern Germany
No full textThe climate sensitivity of radial growth in European beech (Fagus sylvatica L.) was analyzed within a narrow valley in the Swabian Alb (southwestern Germany). We collected stem discs from three aspects (NE, NW and SW) of trees belonging to different social classes. Common climatic factors limiting growth across the valley were identified using a principal component analysis (PCA). Further, we performed hierarchical cluster analysis (HCA), redundancy analysis (RDA) and bootstrapped correlation analysis to reveal differences in chronologies and climate-growth relationships between aspect and social class.
Climatic variables considered in our analyses were monthly and seasonal data on temperature and precipitation, as well as a self-calibrating Palmer drought severity index (sc-PDSI). We identified drought in the period June-August as the most prominent factor limiting growth across the valley. Dominant and co-dominant trees at the NW and SW aspect were found to be particularly drought sensitive, whereas intermediate trees were less susceptible to drought. Underlying causes of established climate-growth relationships are discussed in the context of drought susceptibility, tree-size modulation and tree physiological processes
Spatial Analysis of a mixed Beech, Spruce and Fir stand in the Eastern Alps
No full textIn a forest reserve, located in the Eastern Italian Alps, a 4 ha permanent plot has been set up in a beech-spruce-fir multilayered forest, left to natural evolution for more than 30 years, in order to detect stand structure and spatial patterns. Additionally, within the 4 ha, we selected 1 ha where data related to age were collected (coring all the individuals above 6 cm in diameter) and to test the efficiency of the statistics at 2 different spatial scales. The methods employed were the univariate and bivariate O-ring statistic together with autocorrelation indexes such as Global Moran’s I and local Gi*. Thus, it has been possible to perform both the point pattern and the spatial structure analyses. Diameters’ distribution highlights a slightly multilayered structure for groups whose tend to be even-aged and monospecific. O-ring statistics have highlighted a general aggregation pattern up to the oldest stages while the spatial structure analyses have highlighted a macroscopic trend which divide the stand in two distinct and homogeneous big groups of individuals. Secondly, a different behavior is detected among the species, i.e. the beech is likely to prefere to regenerate under the old spruce and the two conifers prefer to grow in very localized conditions. A huge lack of young individuals has been detected due to deers’ browsing. Lastly, the age has proved to be a fundamental parameter to fully describe, together with the most common species, diameter and height, the structure of forest stands. The comparison between the 1- and the 4-ha analyses has confirmed the key role of the dimension of the larger permanent plot in detecting the whole range of spatial features within a stand.
The results obtained from this work provide an important support for the analyses of similar stands in terms of evolution and natural dynamics occurring after the human pressure decreasing
Auswirkungen der Einbringung von Buche (Fagus sylvatica L.) auf die Artendiversität und Naturnähe von Nadelholzbeständen in Niedersachsen
No full textThe promotion and extension of continuous cover mixed stands with a simultaneous reduction of conifer-monocultures play a major role in current silvicultural practices in Central Europe. It is assumed that the admixture of the natural dominant beech (Fagus sylvatica) in pure non site-specific conifer stands automatically indicates better conditions in terms of nature conservation and forest management. To test this hypothesis three different conifer-beech-comparisons of pure and mixed stands in Lower Saxony are studied, analyzing plant species diversity and naturalness of understory vegetation as one important indicator for the ecological status of forests. Each comparison includes pure coniferous stands (Picea abies, Pinus sylvestris, Pseudotsuga menziesii), mixed coniferous-beech-stands, and pure beech stands on similar acidic mineral soils where the potential natural vegetation will be an oligotrophic beech forest (L u z u l o - Fa g e t um). The age of stands varies between 50 and 150 years. To specify tree species influence on site conditions and vegetation, the study also includes light climate and soil data of the stands. It is observed that, with regard to all comparisons, the admixture of beech reduces plant species diversity but increases naturalness of the stands. The intensity of beech admixture effects differs. While in Scots pine stands the impact of admixed beech is very noticeable, with the mixed stands being nearly identical with pure beech stands, the species change in Douglas-fir and Norway spruce stands proceeds more slowly. Assuming that the status in nature conservation and forest management is improving with increasing plant species diversity and increasing naturalness, the results of this study show a contrary development on a stand scale, as the potential natural vegetation of the L u z u l o - F a g e t u m is in its self very species poor on vascular plants.Die Förderung und Ausweitung von Mischwäldern bei gleichzeitiger Reduktion reiner Nadelholz-Bestände spielt aktuell eine große Rolle im mitteleuropäischen Waldbau. Gemeinhin wird angenommen, dass die Beimischung der standortsgemäßen Buche (Fagus sylvatica) in standortsfremden Nadelholz Monokulturen die Bedingungen im Sinne des Naturschutzes und der Forstwirtschaft verbessert. Diese Hypothese wird auf der Grundlage von drei unterschiedlichen Nadelholz- Buchen-Versuchsreihen geprüft. Im Mittelpunkt steht dabei die Bodenvegetation als wichtiger und sensitiver Indikator für den ökologischen Zustand von Wäldern. Jede Versuchsreihe umfasst reine Nadelholz-Bestände (Picea abies, Pinus sylvestris, Pseudotsuga menziesii), Nadelholz-Buchen- Mischbestände und reine Buchen-Bestände auf sauren Mineralböden, auf denen von Natur aus nährstoffarme Buchenwälder (L u z u l o - Fa g e t um) vorherrschen würden. Das Alter der Bestände variiert zwischen 50 und 150 Jahren. Schwerpunkte der Analyse sind die Artenvielfalt und Naturnähe der Bodenvegetation. Um den Einfluss der Baumarten auf den Standort und die Vegetation zu bewerten, werden die Licht- und Bodenverhältnisse der Bestände charakterisiert. Es zeigt sich, dass mit der Beimischung der Buche in allen Versuchsreihen die Pflanzenartenvielfalt abnimmt und die Naturnähe zunimmt. Unterschiedlich ist dabei die Intensität der Veränderungen. Zwischen den Kiefern-Buchen-Mischbeständen und den Kiefern-Reinbeständen bestehen sehr deutliche Unterschiede im Aufbau der Bodenvegetation, so dass die Mischbestände den Buchen-Reinbeständen bereits sehr ähnlich sind. In den Douglasien- und Fichten-Versuchsreihen vollzieht sich der Artenwechsel vergleichsweise unauffällig und kontinuierlich. Wenn man davon ausgeht, dass der naturschutzfachliche und waldbauliche Status sich sowohl mit zunehmender Phytodiversität als auch bei zunehmender Naturnähe verbessert, so zeigen diese Ergebnisse auf Bestandesebene eine gegenläufige Entwicklung, da das in der Region der potenziell natürlichen Vegetation entsprechende L u z u l o - Fa g e tum von Natur aus sehr artenarm an Gefäßpflanzen ist
( Leaf litter decomposition in the beech forests of Monte Taburno).
No full textDecomposition dynamic showed 3 phases: weight loss in phase I (1st wk) was mainly due to leaching; during phase II (1st yr) decomposition rates were high and varied with beech in the beech stand = fir > beech in the beech-fir stand; during phase III decomposition rates were low and there was some absolute increase in the weight of leaves of both species. N concentration of beech leaves in both stands increased markedly during phase II and slowly during phase III; the increase of N concentration in fir leaves was higher in phase III.-from English summar
Factors determining the occurrence of Flat Bugs (Aradidae) in beech dominated forests
No full textThe habitat requirements of most Aradidae and the decisive factors that influence their occurrence are still poorly understood. To reduce this lack of knowledge a standardised survey of Aradidae in two large beech forest areas of Bavaria (northern Steigerwald and High Spessart) was conducted. The following hypotheses were tested: 1) With increasing habitat tradition (temporal continuity), population densities of Aradidae increase, 2) Increasing dead wood supply supports higher abundance of Aradidae, 3) There are key structures for particular species with respect to type of dead wood, diameter and exposure to sunlight, and 4) The occurrence of particular fungi species determines the occurrence of Aradidae. In our study, Aradidae were sampled in point sample plots by flight-interception traps and time-standardised hand collection. To analyse specific habitat requirements additional sampling was performed to increase the sample size. Four species of Aradidae were observed in the two forest areas: Aneurus avenius, Aradus betulae, A. conspicuus and A. depressus. The results demonstrate that all species have different and specific habitat requirements. Especially for A. betulae habitat tradition of standing dead wood of large dimensions infested by Fomes fomentarius seems to be crucial. Hence, A. betulae was only observed in the Spessart and only at the sites with habitat tradition.Die Habitatansprüche der meisten Aradidae sowie die entscheidenden Faktoren die ihr Auftreten bedingen werden immer noch wenig verstanden. Um diese Wissenslücke zu verringern wurde eine standardisierte Aufnahme der Aradidae in zwei großen Buchenwaldgebieten Bayerns (nördlicher Steigerwald, Hochspessart) durchgeführt. Dabei wurden folgende Hypothesen ge-testet: 1) Die Populationsdichten der Aradidae steigen mit zunehmender Totholztradition, 2) erhöhte Verfügbarkeit an Totholz fördert eine höhere Abundanz der Aradidae, 3) es gibt Schlüsselstrukturen für bestimmte Arten in Bezug auf Totholztyp, -durchmesser und Sonnen-Exposition und 4) das Auftreten bestimmter Pilzarten bestimmt das Vorkommen der Aradidae. Zu diesem Zweck wurden Aradidae im Probekreisen mit Hilfe von Lufteklektoren und zeitnormierte Handaufsammlungen erfasst. Zur Analyse von spezifischen Habitatansprüchen wurden zusätzliche Fänge durchgeführt um die Stichprobengröße zu erhöhen. Vier Arten der Aradidae wurden in den bei-den Gebieten festgestellt: Aneurus avenius, Aradus betulae, A. conspicuus und A. depressus. Die Ergebnisse zeigen, dass alle Arten unterschiedliche und spezifische Habitatansprüche haben. Besonders für A. betulae scheint die Totholztradition, von starkem, von Fomes fomentarius besiedeltem, stehendem Totholz, eine entscheidende Rolle zu spielen. Folglich wurde sie Art nur am Totholz-traditionsreicheren Waldstandort, dem Spessart, gefunden
Seasonal dynamics of epigeic spiders in beech forest of Haltrava
No full textV diplomové práci se zabývám arachnofaunou v oblasti bučin pod Haltravou. Výzkum probíhal od května do října roku 2017 pomocí metody zemních pastí. Oblast byla rozdělena na tři stanoviště A, B a C. První stanoviště představují jen bučiny, druhé je směsí buků a smrků, třetí stanoviště tvoří smrčiny. Nalezené druhy byly vyhodnoceny podle atlasu Pavouci ČR (Kůrka 2015) a uloženy v depozitáři v Západočeském muzeu v Plzni. Celkem bylo nalezeno 376 jedinců, z toho 344 samců a jen 32 samic, kteří byli zařazeni do 12 čeledí a 21 druhů.ObhájenoIn my diploma thesis I explore the arachnofauna in the area of beech forest of Haltrava. The research was from May to October 2017 using the earth traps. The area was devided to three stand - A, B and C. The first stand is only beech forest, second is mixture of beech and spruce, the third is spruce grove. Discovered species were evaluated according to the atlas of Spiders od the Czech Republic (Kurka 2015)and saved in the depository in West Bohemia Museum in Pilsen. It was discovered 376 specimens, which were included in 344 male and 32 female and 12 families and 21 species
Control of the so called leaf loss of European beech (Faguss sylvatica L.) by the weather
No full textThe annual assessed leaf losses and recorded leaf masses of the beech trees are narrowly correlated with the local or regional climate resp. weather (Tab. 1, 3, 4). Due to the multiannual development of shoots and leaves on beech (Fig. 1) the weather/climate of several years during this development influences the leaf canopy and leaf loss of a stand. The multiannual weather index MAWI (KINDall) composed of the weather efficient monthly dates of local and regional precipitation, air temerature and sunshin duration (also global radiation, relative humidity, water saturation deficit) of four years can be roughly correlated (r(2) > 0,98) to the leaf mass and assessed leaf loss of a stand. Therefore laef mass and leaf loss is controlled by MAWI (Tab. 1, 3, 4; Fig 2, 4, 5). The high percentage of preformation of leaf mass and leaf loss during the developmental periods is strongly influenced by the weather data allows a prediction with high pricicion (Tab. 2, 5, 6; Fig. 3, 6, 7). The leaf loss of the stand Harste 78 is narrowly correlated to the multiannual transpiration stress factor (tsf), which is composed of the water saturation deficit of the air, the global radiation and the precipitation (r(2) = 0,8; s. Tab. 7, Fig. 8-10). The author points out on the great importance of the woods and the poor information about them and that the science of woods and forests must be expanded, long-term installed and better organized
Control of the so called leaf loss of European beech (Faguss sylvatica L.) by the weather
No full textThe annual assessed leaf losses and recorded leaf masses of the beech trees are narrowly correlated with the local or regional climate resp. weather (Tab. 1, 3, 4). Due to the multiannual development of shoots and leaves on beech (Fig. 1) the weather/climate of several years during this development influences the leaf canopy and leaf loss of a stand. The multiannual weather index MAWI (KINDall) composed of the weather efficient monthly dates of local and regional precipitation, air temerature and sunshin duration (also global radiation, relative humidity, water saturation deficit) of four years can be roughly correlated (r(2) > 0,98) to the leaf mass and assessed leaf loss of a stand. Therefore laef mass and leaf loss is controlled by MAWI (Tab. 1, 3, 4; Fig 2, 4, 5). The high percentage of preformation of leaf mass and leaf loss during the developmental periods is strongly influenced by the weather data allows a prediction with high pricicion (Tab. 2, 5, 6; Fig. 3, 6, 7). The leaf loss of the stand Harste 78 is narrowly correlated to the multiannual transpiration stress factor (tsf), which is composed of the water saturation deficit of the air, the global radiation and the precipitation (r(2) = 0,8; s. Tab. 7, Fig. 8-10). The author points out on the great importance of the woods and the poor information about them and that the science of woods and forests must be expanded, long-term installed and better organized
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