November 28, 2018

Being behind the times? Assessing the liana-induced impact on forest phenology using an Unmanned Aerial System (UAS).

Lianas reduce growth and increase mortality of their host trees, thereby reducing carbon accumulation in tropical forests by as much as 76%. Increased liana dominance may therefore further reduce carbon uptake and storage and endanger the future of the tropical carbon sink, with serious implications for climate change. Tree canopies suffer from liana infestation, which limits their leaf productivity and leaf area and their reproductive success. Nevertheless, lianainduced impact on phenological processes has received little attention, but is crucial to i) accurately include liana effects in vegetation models and ii) better predict of the fate of tropical forests both due to climate change as well as liana propagation in the future.

This project aims to 1) determine whether liana infestation reduces the photosynthetic capacity of their host trees, and 2) test whether the presence of lianas affect the timing of main phenological processes in the forest, such as leaf fall, leaf flush, fruiting and flowering. The project will involve fieldwork in Panama to collect imagery using an Unmanned Aerial Vehicle (UAV) and an analysis of remote sensing data to derive information on photosynthetic capacity and timing of phenological events in the forest. The student will work with a collaborative supervisory team, composed of physical geographers and ecologists from the School of Geography, as well as from Smithsonian Tropical Research Institute, Panama, and Marquette University, US.

The applicant should be willing to spend time in a relatively isolated area in Panama to collect field data and to learn advanced statistical modelling and remote sensing techniques. Lastly, (tropical) ecological field experience and UAV flying experience are assets, but an enthusiasm for nature and tropical forests is by far the most important prerequisite. Applicants should hold a minimum of a UK Honours degree at 2:1 level, or equivalent, in a subject such as Physical Geography, Environmental Science, Ecology or Natural Sciences.

For further details please contact Dr. Geertje van der Heijden ( and/or Dr. Doreen Boyd (