Botanical Institute and Botanical Gardens Technical University of Braunschweig

Working Group for Vegetation Ecology and Experimental Plant Sociology

Head: Prof. Dr. Dietmar Brandes


[German version]

Research activities:

Publications:



Population biology of selected species

Databases:

The Botanical Institute at the TU Braunschweig







Research Activities:

Vegetation of urban habitats, roads and railways

Flora and vegetation of settlements are investigated in subject to their size, age and geographical position. As a centre of the ruderal vegetation walls and ruins are studied throughout Europe with particular emphasis on Brunswick as a model. The vegetation of the young city of Wolfsburg was studied in detail.

Roads and railways are important linear structures for plant species. The migration of Atriplex micrantha, A. sagittata and A. oblongifolia along motorways and the spreading of Senecio inaequidens to the east were investigated. The vegetation ecology of nitrophytic species is closely related to the vegetation of settlements. Competitive experiments on selected species use different levels of nitrogen and electrolytes.
motorways
Fig. 1:    Atriplex micrantha along northern motorways.
Artenpool
Fig. 2:    Flora along the roads as part of the regional species pool on Majorca.
Germination Fig. 3:    Germination experiments on Bromus tectorum with different levels of nitrogen and electrolytes.


Alien plants

Alien plants are of particular interest and frequently discussed. Often they seem to be threatening but the most problematic aliens are the wooden species Robinia pseudacacia and Prunus serotina and seven highly competitive ornamental plants, which are important in the lower elevations of the low mountain ranges and along rivers coming from the mountains: Fallopia japonica, Fallopia sachalinensis, Helianthus tuberosus, Heracleum mantegazzianum, Impatiens glandulifera, Solidago canadensis and Solidago gigantea.

During the last 20 years a system of long-term monitoring was set up to study and quantify the spreading, niches and adverse effects to the natural vegetation. The monitoring is working for instance in the city of Brunswick, the landscape north of the Harz mountains, the river Elbe and the system of the river Weser, Monte Baldo (Italy), rivers on Rhodes, Corfu, Malta, Majorca, La Palma and Fuerteventura.

The long-term monitoring plots deal with lots of different habitats such as flat roofs, buildings, streets, Botanical Gardens, parks, cemeteries, railways, the harbour, the edge of motorways, river banks and the edge of woods.
Flowering Nicotiana
Nicotiana in Rio de La Palma
Fig. 4:    Nicotiana glauca, a common alien species on Fuerteventura,

left:        flowering plant at the age of one (Botanical Gardens Brunswick),

above:    in the desiccated reservoir of Vega de Río Palmas.


Floodplains

The floodplain of the river Elbe is the most interesting floodplain in Central Europe. The vegetation is investigated intensively. A particular focus is on the different riparian structures as well as on the migration of species along rivers.

In addition the vegetation of alpine rivers, the phytodiversity of torrents on Majorca and Rhodes, the flora and vegetation of the barrancos on La Palma and the flora of episodically rivers on Fuerteventura is studied.
Transect
Fig. 5:    Transect through the groyne field upstream to the shipping pier of Pevestorf (Lkr. Lüchow-Dannenberg).
Frequency
Tab. 1:    Frequency of Bidentetea-species in 11 groyne fields between Magdeburg and Lenzen.
Floodplain Fig. 6:    Floodplain on Rhodes with Nerium oleander (Oleander).


Islands and isolated habitats

While flora and vegetation of Fuerteventura is investigated as a model of an island, calcareous grasslands, inland salt marshes and woods are interesting because of their isolation to each other. They are situated in the agrarian landscape which is intensively used. Therefore these habitats are similar to islands because of missing networks.

The research is done on phytodiversity, vegetation and similarities. The area north of the Harz Mountains is characterized by an interesting gradient from subatlantic climate in the western part to sub continental climate in the eastern part. The analysis of the floristical data obviously divides the investigated plots into two groups: The continentally influenced (eastern) steppes containing a high number of xerothermic relicts, and the western grasslands, which are characterized by subatlantic-submediterranean species, whereas the pontic-pannonic species are missing completely. The composition of these groups is independent from the method of comparison. Classification based on the complete floristical data, or only considering the biogeographically important species, or the floristic-statistical approach give almost identical results.

The isolation is also investigated on the level of species. A diploma thesis is dealing with the populations of Eryngium campestre from locations of the river Oder in the east up to the river Rhine in the west by using RAPDs and AFLPs.
Clusteranalysis
Fig. 7:    Cluster analysis of the similarity index using complete linkage.
Eryngium
Fig. 8:    Eryngium campestre.


Papers in English


Population biology of selected species


Flower© 2004 Working Group for Vegetation Ecology and Experimental Plant Sociology
Matthias Evers
E-Mail: ub@tu-bs.de

12.11.2004