Pollination biology

Eine männliche Prachtbiene (Euglossa sp.) beim Anflug an die Blüte von Gloxinia perennis (Gesneriaceae). (© W. Hödl)

(© W. Hödl)

Eine stachellose Biene (Trigona fulviventris) beim Sammeln des Blütenharzes von Clusia valerioi (Clusiaceae). (©  W. Hödl)

(© W. Hödl)

Pollination biology is the field of botany that deals with the pollination (tranfer of pollen to the stigma) and fertilisation of the flowers of "flowering plants" (gymno- and angiosperms) by abiotic (wind, water) and biotioc vectors (various groups of insects, vertebrates). The field dwas opened in 1793 by the epoch-making book entitled (in translation) "The uncovered secret of nature in the structure and fertilisation of flowers) by C. K. Sprengel. While wind- and water-pollinated flowers are inconspicuous and of simple architecture, in the animal-pollinated flowers an enormous diversity with sometimes bizarre specialisations has evolved. Insect pollination is found worldwide, whereas flower that are pollinated by vertebrates (birds, bats, non-flying mammals) are found only in the tropics.

Studies at the Department (S. Vogel, A. Weber) often relate to the correlation between flower structure and structure/behaviour of the flower-visiting animals. Our native black cumin (Nigella sativa, Ranunculaceae) has not only very complex flowers, but also shows well-coordinated movements of the stamens and styles that ascertain a contact btween the anthers and styles by the attracted insects. Of special interest are tropical flowers that provide floral rewards in the form of fatty oil, perfume and resind instead of the "classical" rewards pollen and nectar. The fatty oil is used (together with pollen) by specialised bees as a food for the brood, perfume is used by male orchid bees indeed as a perfume to attract females, and resind is used for nest construction and impregnation. Another current research project relates to the evolution, stepwise improvem,ent and functional differentiation of kettle trap in aroids.

Dispersal ecology (diasporology) investigates the connex between the structure of fruit and seeds and their dispersal by wind, water and animals. A focus at the department is the examination of fruits and seeds that are dispersed by ants (V. Mayer).