Local, population, community, and ecosystem processes shaping a tropical forest plant community
In this work, I used an array of large-scale datasets to examine ecological process that shape communities at four distinct levels. The focal dataset consisted of two censuses 10-years apart (2007-2017) of a liana community consisting of 117,100 rooted stems from 71,884 individuals in an old-growth 50ha forest dynamics plot on Barro Colorado Island (BCI), Panama. First, I focused the liana dataset to 55,156 liana individuals of 86 species with sufficient populations to examine how local interactions between species result in highly stable and deterministically controlled community structure.
The observed community stability is the result of a predictable relationship between changes in local species demographic process with changes in relative abundance. This relationship preserves species diversity and maintains most species at a predictable relative abundance within a community. Second, I used all 71,884 liana individuals to examine how population demographics vary between species demonstrating the potential for varied life-history strategies amongst species within the community. The observed demographic diversity enhances the potential of species diversity through niche differentiation.
Third, I combined the liana dataset with two 10-year censuses of canopy height for BCI: aerial LiDAR censuses from 2009 and 2019 and tree censuses from 2005 and 2015. With these three datasets combined, I examined the effect lianas had on ecosystem level functioning and forest structure. I show that increasing liana density has a negative effect on canopy height, altering forest structure. The altered forest structure led to inconsistencies in determining canopy height where lianas reduce tree carbon storage capacity beyond current estimates through greater height reductions than previously thought. Thus, increases in liana density reduce forest canopy height and diminish tropical forest carbon storage capacity.
Conferencista
David Defilippis
Ver más
David Defilippis
I recently graduated with a doctor of philosophy in ecology with a long history of funding support and experience in industry and academic research. During my undergraduate studies I was awarded a Ronald E. McNair fellowship in the summer of 2012, and in the summer of 2014, I was awarded a Research Experience for Undergraduates Fellowship from the Smithsonian Tropical Research Institute.
Shortly after starting my graduate studies at Marquette University I was awarded an National Science Foundation Graduate Research Fellowship in 2017, and in 2018 I was awarded a Graduate Assistance in Areas of National Need fellowship from the United States Department of Education.
I work with large datasets normally comprising multiple hectares of forest inventory plots across decades of censuses. I use these data and a Bayesian probabilistic approach to better understand how communities assemble, what maintains their diversity and ecosystem functioning, focusing primarily in Neotropical and Temperate forest biomes. I was not always interested in academia, the first several years after high school I worked as a diesel mechanic and a metal fabricator. After finishing my undergraduate studies I returned to industry and worked as a software engineer for two years before starting my graduate degree.