Marie Hoensbroech (Carl von Ossietzky-Universität Oldenburg)
Marie Hoensbroech's Master thesis was awarded with the Prize for the Best Plant Science Master Thesis, which was carried out at Carl von Ossietzky-University Oldenburg in the year 2024 with the title:
What goes up, must come down? Vertical wind dispersal of epiphyte seeds in a Panamanian rainforest
The movement of plant diaspores by wind has been simulated many times before, but this is the first time that it is done for epiphytes in a rainforest.
True epiphytes commensally live on other plants, typically trees. They are unlikely to survive on the ground, but otherwise they can occur at all heights within a forest: from the base of a tree to its outermost crown. Yet, often, their distribution is clumpy or limited to a certain zone within a forest (e.g., only between 10 and 15 m above ground). Can dispersal explain these patterns? As most epiphyte species are wind-dispersed (only few are animal-dispersed), knowledge is needed of the vertical air movements. Therefore, Hoensbroech installed sonic anemometers at different heights and close to different trees in a Panamanian rainforest (see picture). The collected data was fed into a dispersal model that simulates how epiphyte seeds move within the forest. Since both strength and frequency of air movements increase with height, seeds released lower down disperse shorter distances, more often remain in the proximity of their mother plant and are more likely to land on the ground. Those released higher up are generally dispersed greater distances and are more likely to reach a different forest zone or even end up above the forest. In summary, dispersal can at least partially explain epiphyte distribution patterns, but challenges during later life stages are likely to play a role as well.
___
Marie Hoensbroech conducted this work at the Institute for Biology and Environmental Sciences in the working group of Prof. Dr. Gerhard Zotz.
