The main campus has a very diverse tree population, as a 2018 survey during the development of the campus design master plan showed. The campus is home to about 80 different species of trees. Maple and small-leaved linden are the most common, followed in almost equal proportions by ash, black locust and various types of cherry tree. The third most common tree species are common hornbeam, horse chestnut and various types of oak and poplar.
There are not many old or mature trees on campus. As the campus has become more developed, there is less space for trees with large crowns. As a result, solitary trees or small groups of trees predominate. Traffic safety measures, renovation work, and construction work all require frequent interventions in the tree population. The tree sponsorship initiative actively promotes the development of the tree population, and numerous new plantings have been achieved since 2018 thanks to sponsorships.
The avenue of horse chestnut trees with imposing crowns by the Auditorium Center creates a striking image. The horse chestnut (Aesculus hippocastanum) is a deciduous tree that can grow up to 30 meters high. Its white flowers provide plenty of nectar for insects. This tree is native to the Balkans and is often planted in parks or used as an avenue tree in Central Europe.
With its columnar crown and a growth height of up to 30 meters, the Canadian poplar (Populus ×canadensis) is a distinctive and space-defining tree on campus. Rows of trees and short avenues lead the way along pathways. It is a hybrid of the North American eastern cottonwood (Populus deltoides) and the native black poplar (Populus nigra).
A pedunculate oak (Quercus robur) with a majestic crown graces the front entrance of the Auditorium Center. The Irish oak (Quercus petraea) is also at home on our campus. Both species are native to Europe. They are of great ecological importance as they provide a habitat for a large number of insects (including around 100 species of beetle), birds, mammals, lichens and fungi.
The Japanese cherry (Prunus serrulata) is a deciduous tree that can grow up to 12 meters high. The full splendor of its flowers only unfolds for a few days in April; the flowering period is quickly over by May. The flowers and intense color of the foliage in the fall make this species an attractive ornamental tree. The abundance of flowers provides insects with plenty of nectar and pollen.
The Norway maple (Acer platanoides) can reach a height of 20 meters and has a wide, densely-leaved crown. The species of tree is very robust and is resistant to both heat and cold. The yellow-green flowers have a high nectar content and are an important source of food for insects in early spring. Its autumn foliage captivates with a wealth of yellow and red tones.
The golden chain tree (Laburnum x) reaches a height of 7 meters. Due to its yellow flowers, this is an impressive decorative tree in gardens and parks. This deciduous tree is not native to Central Europe. Pollinating insects utilize the pollen. Its leaves provide caterpillar as food for butterflies. But be careful! All parts of this tree, especially the seeds, are poisonous.
Behind the biology building and the administrative building at Bergstraße 69, you will find a meadow with some orchard trees. These are medium to tall apple and pear trees. The fruit tree blossom in spring is an important source of food for many insects. Orchard meadows are of great ecological importance due to the diversity of their feeding and nesting habitats.
Wildlife
Trees not only provide decoration, they also perform important ecological functions, helping to improve the local climate by increasing evaporation, producing oxygen, and reducing dust and pollution. Trees provide precious habitats for birds, insects and mammals. They provide nesting opportunities and food sources.
The green-brown patterned lime hawk-moth (Mimas tiliae) was a special find. These moths are only active between May and June in order to reproduce. The caterpillars, on the other hand, feed on the leaves of various deciduous trees (linden, elm and alder). After each meal, the leaf that was being eaten falls to the ground. This is a sure sign that caterpillars are above in the trees.
The Eurasian nuthatch (Sitta europaea) is an excellent climber and can climb upside down along tree trunks to collect insects. In winter it eats seeds and nuts. It is a tree hole nesting bird that likes to move into old woodpecker cavities. It has a preference for open mixed forests, parks and gardens with old trees. This small songbird can often be spotted on campus.
The Eurasian chaffinch (Fringilla coelebs) belongs to the finch family of birds. The males have red-brown plumage with a blue-gray cap. Females and young are gray-brown. It looks for its food on the ground. Berries, all kinds of seeds (beechnuts), insects and spiders make up its preferred diet. It lives in forests, but can also be spotted in parks and gardens with old trees.
Nesting boxes are on campus for cavity-nesting and semi-cavity nesting birds The great tit and blue tit (Parus major, Cyanistes caeruleus) are cavity nesters, as are all bird species that build their nests in holes. Species that breed in niches and crevices, such as the robin (Erithacus rubecula), prefer half-open nest boxes. Nesting boxes also provide shelter for insects and small mammals.