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Speaker: Dr Stephanie Bohlman, Associate Professor in the School of Forest Resources and Conservation, University of Florida (currently on sabbatical at the German Centre for Integrative Biodiversity Research, Leipzig)
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.