Persönlicher Status und Werkzeuge

Sprachwahl

Vegetationsdynamik / Vegetation Dynamics:

Prozesse der raum-zeitlichen Musterbildung der Vegetation nach der initialen Bereitstellung potenziell besiedelbarer Flächen (Primärsukzession)

Prof. Dr. Anton Fischer, Dr. Susanne Winter, Dipl.Biol. Markus Zaplata (seit 1. Mai 2008)

In  Z1 des Sonderforschungsbereich / Transregio 38: Strukturen und Prozesse der initialen Ökosystementwicklung in einem künstlichen Wassereinzugsgebiet

Fortlaufende Dokumentation und Analyse der Vegetationsentwicklung auf der Projektfläche „Hühnerwasser“

Hypothesen

H1: Die sich zu Beginn etablierenden Individuen und Arten legen die mittelfristig ablaufenden sukzessionalen Entwicklungspfade fest.

H2: Die Bestandesentwicklung wird durch kleinflächige mechanische Eingriffe und Strukturneubildungen punktuell immer wieder unterbrochen; an diesen Stellen können sich neue Individuen bereits etablierter Arten ansiedeln, es können sich aber auch Arten früherer Entwicklungszustände erneut etablieren bzw. neue Arten erstmals einwandern.Das Fachgebiet Geobotanik betreut zwei Aufgabenbereiche:

(1) Fortlaufende Dokumentation und Analyse der Vegetationsentwicklung im Wassereinzugsgebiet „Hühnerwasser“ (einschließlich Biomasseentwicklung)

(2) Anlage und Durchführung eines Sukzessionsexperimentes auf der „Experimentalfläche“

Die Dokumentation und Analyse der Vegetationsentwicklung umfasst folgende Bereiche:

Sameneintrag: Diasporen, die von außen in das neu entstandene Gebiet vordringen.

Samenbank: Qualität (Artenspektrum) und Quantität des Vorrats an keimfähigen Diasporen im Boden zu Beginn der Sukzession.

Vegetationsentwicklung: im 20 m x 20 m Raster seit Herbst 2005 fortlaufend.

Biomasseentwicklung

 

(2) Anlage und Durchführung eines Sukzessionsexperimentes auf der „Experimentalfläche“

Ausgehend von einer unbeeinflussten Entwicklung (parallel zum „Hühnerwasser“) umfasst das Sukzessionsexperiment folgende Varianten in jeweils fünffacher Wiederholung:
- Einbringen von Pflanzenarten aus fortgeschrittenen Sukzessionsstadien bei Versuchsbeginn:
(1) Calamagoistis epigejos als Art einer fortgeschrittenen Offenlandsukzession und
(2) Brachypodium sylvaticum als Waldart.
Die Arten werden zum einen zentral in der Fläche ausgebracht (also mit Möglichkeit der Expansion auf der Fläche) und zum anderen (bei gleicher Individuenzahl) auf der ganzen Fläche verteilt (also mit Möglichkeit der Verdichtung).
- Bestandesentwicklung ohne bzw. mit zusätzlicher Konkurrenzvegetation durch Festuca rubra-Einsaat.
- Bestandesentwicklung ohne bzw. mit zusätzlicher mechanischer Störung des Bestandes/des Bodens (Schaffung von Eintrittspforten für neue Arten in den Bestand).

Forest dynamics after bark beetle attack in the higher reaches of the Bavarian Forest (1998-2001):

Maria Luise Bauer

The chair of forest and forestplaning examines in cooperation with the section geobotany the modification of soil vegetation and natural reproduction of stands after bark beetle disease. The research will be done in an interdisciplinary project on large field studies in high reaches.

The project started with:

  • Creation of long-term observation areas
  • Documentation of competition between natural reproduction and soil vegetation
  • Analysation of development, modification of natural reproduction and soil vegetatio
  • Description of dying and break-down of aged spruce stands

The project takes part in present researches which are located in the national parc 'Bavarian Forest' and can be seen as a link between them. The investigation offers a possibility for exact descriptions of the status quo and for development forecasts, including most of the important factors like location, soil vegetation, previous stock stands, dead layers, etc..

The experimental design, compiled by Mr. Msc. El Kateb, covers the old part of the national parc (so called inner region) and the extension area. A comparison between the inner part (a natural forest and an intensively (until 1997) managed forest (the extension area) is possible, because the last mentioned area essentially results from the former Forest Administration Office of Zwiesel.

Additionally stands are investigated on slope and plateau. The comparison is done between stands where old trees were killed partially by bark beetle and totally dead ones. The investigation will be continued during a long-time period by introducing long-term observation surfaces. The main question of how do spruce stands (Calamagrostis villosae-Piceetum) develop after wide dying of previous stock level, can be answered.

Forest vegetation developement in the Bavarian Forest National Park following the 1983 windfall event (1988-heute):

Anton Fischer und Studenten

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; in collaboration with Potsdam Institute of Climate Impact Research.

Forest dynamics following windthrow in 10 forest districts in Bavaria (1990-2002):

Gerhard Märkel

The storms "Vivian" and "Wiebke", that crossed Central Europe in early spring 1990 (26.2. to 1.3. 1990) destroyed many forest stands in Bavaria. In order to obtain information about the development of natural and planted tree regeneration and vegetation development following windthrow more than fifty permanent observation plots were established in the more heavily affected forest regions of Bavaria. The first record took place in 1991, the second in 1995, and the third in 2000. Data of the development of ground layer vegetation and tree regeneration were recorded together with information on site conditions and structure of the stands. Final analysis of the data will start after finishing the year 2000-record.

Vegetation dynamics following forest stand destruction by snow avalange in the Berchtesgaden National Park (1988-heute):

Anton Fischer und Studenten

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)