CANCELLED - Inter- and intra-specific variation in tropical canopy phenology: Insights from field data and images from Unmanned Aerial Vehicles (UAVs)
OCTF seminar followed by drinks – all welcome, booking required

Phenology, a sentinel of climate change and mediator of ecosystem processes, is poorly understood in tropical versus temperate forests. Our lack of quantitative data results in part from the high diversity and limited synchrony of phenological patterns within and among tropical species, as well as difficulty in observing leaf cover changes, especially upper canopy trees in dense forests, over time and large areas. A time series of unmanned aerial vehicle (UAV) images from Barro Colorado Island, Panama was used to quantify the leaf cover of thousands of individual trees. By linking the leaf cover patterns with species identity, we quantified intra- and interspecific variation in phenological metrics such as timing of leaf loss and leaf flush and degree of deciduousness. We compare these quantitative metrics of phenology with commonly-used functional groupings for tropical phenology. We show how with these types of data, we can answer questions about the drivers and correlates of phenology among and within species, including how liana cover affects phenology, how other species traits vary with phenology, and how phenology varies with environmental and neighborhood characteristics. We discuss the consequences for these patterns of phenological variation for ecosystem processes.

Dr. Bohlman is an associate professor in the School of Forest Resources and Conservation at the University of Florida in Gainesville, Florida, USA. She is a forest ecologist with a focus on landscape-scale patterns and processes in tropical forests. To answer large scale questions, she uses a combination of remote sensing, field data and modeling. Her current projects focus on tropical forest phenology, impacts of Amazon dams on riparian and upland forests, remote sensing-based approaches to mapping tree demography, and scaling species and functional trait patterns from U. S. National Ecological Observatory Network (NEON) data. She is currently on sabbatical at the German Centre for Integrative Biodiversity Research (iDiv) and is a research associate at the Smithsonian Tropical Research Institute (STRI) in Panama.
Date: 8 February 2019, 16:15 (Friday, 4th week, Hilary 2019)
Venue: Dyson Perrins Building, off South Parks Road OX1 3QY
Venue Details: Herbertson Room
Speaker: Dr Stephanie Bohnman (University of Florida)
Organising department: Oxford University Centre for the Environment
Organiser: Jane Applegarth (University of Oxford, Oxford University Centre for the Environment)
Organiser contact email address:
Host: Professor Yadvinder Malhi (University of Oxford)
Part of: Oxford Centre for Tropical Forests
Booking required?: Required
Booking url:
Cost: Free
Audience: Public
Editor: Jane Applegarth