On 18 Januar 1986 at the east-looking slope of the Kleiner Watzmann in the Berchtesgaden National Park a snow avalanche came down from an elevation of about 2.000 m to the Königssee near St. Bartholomae (610 m above see level). It destroyed 12 to 15 ha of old growth forests dominated by beech (Fagus sylvatica); about 2.000 m3 of wood were thrown down. The soil survace was not intensively effected by the snow avalange. Because the area is situated in the central protection zone of the national park no clearing procedure was done, and a free stand develeopment without any direct impact of man is allowed to take place. In 1989 permanent plots (3 transects, each starting in the surrounding forest and crossing to avalanche area) were established. Vegetation and stand structure records were carried out in 1989, 1994 and 1999. Vegetation development in the first place is characterised by (1) a re-establishment of the tree layer by the (beech) trees, which were bent to the ground but not killed by the avalanche, (2) by seedling and sapling establishment (especially Acer and Fraxinus, but not by pioneer trees) and (3) by continuing floristic composition of the ground vegetation (coverage increasing or decresing depending on the light conditions).
Das vom Bereich Spezielle Botanik koordinierte interdisziplinäre Langzeitprojekt stellt ein Gemeinschaftsvorhaben der Universität Leipzig, des Umweltforschungszentrums Leipzig-Halle und der Stadt Leipzig dar. Am Projekt sind Biologen unterschiedlicher Fachrichtungen sowie Forstwissenschaftler und Meteorologen beteiligt. Das Themenspektrum reicht von strukturellen, funktionellen, genetischen und ökosystemaren Aspekten, über Fragestellungen zur Biodiversität und Verbreitung bis hin zur angewendeten Forschung auf den Gebieten Bioindikation, Forstbotanik und Umweltschutz.
The basidiomycete Armillaria mellea s.l. is one of the most important root rot pathogens of forest trees and comprises several species. The aim of the project is to identify the taxa occurring inSwitzerland and to understand their ecological behaviour. Root, butt and stem rots caused by different fungi are important tree diseases responsible for significant economic losses. Armillaria spp. occur world-wide and are important components of many natural and managed forest ecosystems. Armillaria spp. are known saprothrophs as well as primary and secondary pathogens causing root and butt rot on a large number of woody plants, including forest and orchard trees as well as grape vine and ornamentals. The identification of several Armillaria species in Europe warrants research in the biology and ecology of the different species. We propose to study A. cepistipes for the following reasons. First, A. cepistipes is dominating the rhizomorph populations in most forest types in Switzerland. This widespread occurrence contrasts with the current knowledge about A. cepistipes, which is very limited. Second, because the pathogenicity of A. cepistipes is considered low this fungus has the potential for using as an antagonist to control stump colonising pathogenic fungi, such as A. ostoyae and Heterobasidion annosum. This project aims to provide a better understanding of the ecology of A. cepistipes in mountainous Norway spruce (Picea abies) forests. Special emphasis will be given to interactions of A. cepistipes with A. ostoyae, which is a very common facultative pathogen and which often co-occurs with A. cepistipes. The populations of A. cepistipes and A. ostoyae will be investigated in mountainous spruce forests were both species coexist. The fungi will be sampled from the soil, from stumps and dead wood, and from the root system of infected trees to determine the main niches occupied by the two species. Somatic incompatibility will be used to characterise the populations of each species. The knowledge of the spatial distribution of individual genets will allow us to gain insights into the mode of competition and the mode of spreading. Inoculation experiments will be used to determine the variation in virulence expression of A. cepistipes towards Norway spruce and to investigate its interactions with A. ostoyae.
Populations of P. fortinii from allover Europe are examined using microsatellites to construct gene genealogies and infer evolutionary history. The tree-root endophyte Phialocephala fortinii s.l. (mitosporic Ascomycota) is the dominant colonizer of conifer root systems in forests in the northern hemisphere. P. fortinii s.l. is genetically highly diverse and forms a complex of several cryptic species. Recombination occurs or has occurred within cryptic species and to some extent also among them (introgression). Cryptic species occur sympatrically and they can form large thalli, but it remains unclear whether the observed patterns of spatial distribution reflect local climax situations or are the results of recent gene and genotype flow. One of the key objectives will be to estimate population genetic parameters (eg. migration rates, genotype flow, recombination) within and among populations of cryptic species in forests where man-mediated genotype flow can be excluded. Other key objectives are the determination of the number, frequency, distribution and evolutionary history of the cryptic species in Europe and to identify the driving forces for speciation. The approach will be multidisciplinary and will include standard mycological and microbiological methods as well as molecular genetic techniques such as microsatellite fingerprinting and DNA sequencing. The evolutionary history of haplotypes at both the population and species level will be reconstructed and the results will be compared with known patterns of pleistocenic glaciations and postglacial recolonization of host trees. The project will be a significant contribution to the understanding of the population and evolutionary genetics of a versatile and ecologically extremely successful fungal genus and it will shed light on the effects of pleistocenic and postglacial climatic changes on fungal speciation.
In the Bavarian Forest National Park a brief, but intense storm event on 1 August 1983 created large windfall areas. The windfall ecosystems within the protection zone of the park were left develop without interference; outside this zone windfall areas were cleared of dead wood but not afforested. A set of permanent plots (transect design with 10 to 10 m plots) was established in 1988 in spruce forests of wet and cool valley bottoms in order to document vegetation development. Resampling shall take place every five years; up to now it was done in 1993 and 1998. On cleared areas an initial raspberry (Rubus idaeus) shrub community was followed by pioneer birch (Betula pubescens, B. pendula) woodland, a sequence well known from managed forest stands. In contrast to this, these two stages were restricted to root plates of fallen trees in uncleared windfalls; here shade-tolerant tree species of the terminal forest stages established rather quickly from saplings that had already been present in the preceeding forest stand. Soil surface disturbances are identified to be causal to the management pathway of forest development, wereas the untouched pathway is caused by relatively low disturbance levels. The simulation model FORSKA-M is used to analyse different options of further stand development with a simulation time period of one hundred years.
Neben Studien zur Diversität von Gefäßpflanzen in ausgewählten Untersuchungsflächen wurde der Erforschung der endemischen Palmenart Normanbya normanbyi besondere Aufmerksamkeit gewidmet. Im Mittelpunkt stehen Studien zur Blüten- und Fruchtökologie. Dabei wurde u.a. eine bisher unbeschriebene Gattung der Gallmücken entdeckt. Der interdisziplinäre Forschungsansatz soll wesentliche Erkenntnisse über Tier-Pflanze-Interaktionen in Regenwäldern liefern. Hauptaugenmerk liegt auf der Erfassung der Blüten- und Fruchtphänologie eines tropischen Tieflandregenwaldes in Nordostqueensland. Das Projekt beinhaltet die Erfassung der Phänologie aller Unterwuchsarten, Lianen und Baumarten in einer 1 ha großen Untersuchungsfläche. Weiterführend wird die Blühphänologie einer ausgewählten Palmenart Normanbay normanbyi erfasst und mit Hilfe molekulargenetischer Methoden im Zusammenhang mit der Verwandtschaftsstruktur ausgewählter Populationen betrachtet. Die Feldarbeiten für das 2003 begonnene Projekt wurden im Juli 2005 abgeschlossen.
Die Akkumulation und Stabilität der organischen Bodensubstanz resultiert aus der Balance zwischen den zwei biologisch regulierten Prozessen der Humifizierung und der Mineralisation. Boden-Mikroorganismem sind in besonderem Umfang in diesen Prozessen involviert, wobei neben Bakterien Bodenpilze eine herausragende Rolle spielen. Die Enzymgruppe der Laccasen ist in der Lage organische Moleküle aus der Streu und aus dem Humus vollständig zu mineralisieren. Das laufende Projekt befasst sich mit der Analyse der räumlichen und saisonalen Variabilität von Diversitäts- und Expressionsprofilen der Laccasegene.
The hypothesis that the dark septate root endophyte Phialocephala fortinii provides biological control of Phytophthora diseases to trees is tested under two temperature regimes. Phytophthora spp. are very aggressive plant pathogens affecting also woody plants in the natural environment. Studies on biological control of Phytophthora diseases are scarce, but antagonistic effects of endophytic fungi have been demonstrated in a few cases. In temperate and boreal forests, conifers are much less susceptible to Phytophthora diseases than deciduous broadleaf trees, whereas their roots are very frequently colonized by dark septate endophytes (DSE) with Phialocephala fortinii s.l., a supposedly asexual ascomycete, being the dominant component. This fungus also colonizes hardwoods, but to a lesser degree. Recent population genetic studies showed that P. fortinii s.l. consists of at least 15 reproductively isolated cryptic species (CSP). We hypothesise that P. fortinii s.l. may protect its host from Phytophthora disease depending on CSP and environmental conditions. A model system will be developed and applied to test this hypothesis using Norway spruce (Picea abies), beech (Fagus sylvatica) and Phytophthora citricola. The experimental program will be multidisciplinary in approach and include molecular, mycological, phytopathological (infection experiments, epifluorescence microscopy) and statistical methods.
In this study important processes determining the compositional biodiversity of forest stands are investigated. The central goal is to find out the mechanisms leading to a certain biodiversity after natural and management disturbances. In the national park Bayerischer Wald experimental plots in forest stands with different disturbance regime are selected: - untouched for a long time, - Norway Spruce killed by bark beetle, - single tree selection silviculture - clearcut on small areas (up to 1 ha). Three important organismic groups are under study: beetles, fungi and plants. The first group is investigated by the Chair of Applied Zoology, the second by the Division of Systematic Botany. In the teaching unit Geobotany the effect of small scale soil disturbances on diversity of the ground vegetation is examined. Experimental plots of 0,5 m2 are digged up and the reaction of the vegetation is monitored for two years. Exposed mineral soil is a favourable site for germination and establishment for many species of the species pool. Thus soil disturbances may have a positive effect on species richness. The soil seed bank plays an important role for vegetation regeneration after disturbance. Therefore soil samples are taken and cultivated in a greenhouse. It is hypothesised that the soil seed bank is richer in seed and species number in managed forests than in those forests without direct human influence. To monitor seed rain we expose seed traps in the summer season. Light is an important trigger for the germination of species. Linking the reaction to soil disturbances under different light conditions to the biodiversity of the community helps to widen our understanding of the effect of disturbance regime on biological diversity. The comparison of unmanaged to managed forests enables us to contribute important aspects to the discussion on the effect of forest management on biological diversity.
Das Befahren von Waldböden mit immer schwereren Forstmaschinen zieht Bodenveränderungen nach sich, die im Widerspruch zur Nachhaltigkeit forstlichen Handelns stehen können und damit aufmerksam beobachtet werden. Die Forschungen auf diesem Gebiet befassen sich seit rund 3 Jahrzehnten einerseits mit der Quantifizierung der Bodenveränderungen und der Ableitung von Grenzwerten ökologischer Verträglichkeit. Andererseits wird versucht, die Belastungen, die von einer Maschine ausgehen, zu messen, wobei bisher nicht über Laborbedingungen hinausgegangen wurde. Das Neue am Projektansatz besteht darin, dass die Belastung nicht mittelbar auf dem Untergrund, sondern unmittelbar im Reifenprofil gemessen wird. Damit sind nicht nur Laborversuche, sondern auch Freilandversuche im praktischen Maschineneinsatz möglich. Es ergibt sich folgender Versuchsablauf: - Entwicklung eines Messsystems, bei dem die Kräfte unmittelbar im Reifenprofil gemessen werden können - Messung der vom Reifen auf den Boden übertragenen Belastungen bei definierten Kraftkurven im Labor - Messung der Belastungen unter Freilandbedingungen bei kontrollierten Kraftkurven - Messung im realen Maschineneinsatz zur Erfassung der praktisch auftretenden Kräfte und Ableitung von Kennwerten und Kraftspektren statischer und dynamischer Belastung - Messung der Beanspruchungen im Boden unter kontrollierten Freilandbedingungen zur Ableitung von zulässigen Belastungs-Grenzwerten - Entwicklung von Wenn-dann-Regeln und Aufstellung praktischer Handlungsempfehlungen.
| Origin | Count |
|---|---|
| Bund | 23 |
| Land | 1 |
| Type | Count |
|---|---|
| Förderprogramm | 23 |
| License | Count |
|---|---|
| offen | 23 |
| Language | Count |
|---|---|
| Deutsch | 10 |
| Englisch | 14 |
| Resource type | Count |
|---|---|
| Keine | 22 |
| Webseite | 1 |
| Topic | Count |
|---|---|
| Boden | 23 |
| Lebewesen & Lebensräume | 23 |
| Luft | 23 |
| Mensch & Umwelt | 23 |
| Wasser | 23 |
| Weitere | 23 |