Research
Hot-drought effects on European trees.
Having shifted from the tropics back to the temperate zone for the time being, I've dug into some new projects to explore the effects of heat, drought, and combined hot-drought on leaf thermal dynamics and hydraulics in common European tree species. More coming soon!
Heat tolerance and trait acclimation in urban trees.
Using the urban heat island effect in Miami, Florida as a 'found experiment' to simulate the effects of climate change, I investigated acclimation to elevated temperatures in commonly planted street trees. For a simple overview of urban heat islands and their utility to study global change, see our paper in Frontiers for Young Minds!
So far, we have found very limited acclimation of thermoregulatory traits and thermal tolerances in our species, but perhaps a greater ability to acclimate in species that are adapted to greater seasonality (i.e., species from higher latitudes). Read more in our publication in Tree Physiology!
Despite a weak acclimation response and consequently low leaf thermal safety margins at high temperatures, we also didn't find any increases in the thermal optimum of photosynthesis in hotter areas of the city. It's likely that this lack of acclimation response of net photosynthesis is due to stomatal limitation. Read more in our publication in Plant, Cell & Environment!
While my functional trait work is limited in scope to some of the most common trees on Miami's streets, I'm also interested in how Miami's 250+ tree species will fare with future climate warming so that we can create an informed plan for the future of our urban tree community. Climate warming by 2100 will make Miami inhospitable to many of the street trees we currently utilize, including live oak and cabbage palm. Native tree species will be disproportionately impacted by warming compared to exotic trees. See our paper in Urban Forestry & Urban Greening for more details.
Acclimation of trees to elevated temperatures in the Amazon.
As global warming progresses through this century, novel climates are forming in much of the lowland tropics, including the Amazon rainforest. The environmental changes occurring there are unprecedented, making it difficult to predict how forests will continue to respond to change into the future.
To overcome the challenge of studying how Amazonian trees will respond to hotter temperatures, I have been working at a unique site in the Peruvian Amazon, where super-heated water in the Earth's crust emerges to form the Boiling River. The river runs so hot that it heats the air in the forest surrounding the river, creating strong thermal gradients over very short distances (a difference of ~11 C over ~0.5 km).
With the help of this 'natural experiment' for climate change, we have been investigating how tree diversity and function are impacted at super-hot growing temperatures:
See highlights of our research at the Boiling River from Mongabay, BBC Futures, and New Phytologist.
Taxonomy, distribution, and biology of rare magnolias.
Equipped with a Fulbright award, I collaborated with Lou Jost and the EcoMinga Foundation to expand scientific knowledge on two recently-discovered but poorly known species of Magnolia in the eastern cloud forests of Ecuador.
Starting with only a handful of known individuals each of M. vargasiana and M. llanganatensis, I identified more than 300 more trees belonging not only to these species, but also to a putative natural hybrid of the two.
With increased information on their distributions, population structure, leaf and floral morphologies, and phenologies, we published the first conservation assessments of M. vargasiana (VU) and M. llanganatensis (EN) on the IUCN RedList.
Temperature response of net photosynthesis in alpine vegetation.
In this project, we explore the relationship between diurnal net photosynthesis, leaf temperatures, and air temperatures in Norwegian alpine plants across an elevational gradient.
Tree diversity in Sierra Nevada de Santa Marta, Colombia.
Due to its geographic isolation from the Andes and unique elevational gradient, the Sierra Nevada de Santa Marta (SNSM) is recognized for its high rates of endemism, especially in birds, amphibians, and reptiles. Despite the very few studies carried out on plants, high rates of endemism have been found in bryophytes and in the Melastomataceae family. However, rigorous inventories of other plant groups are lacking above 1000 m asl in this ecoregion.
The Jungle Biology Lab spearheaded a project with the Cartagena Botanic Garden and the ProAves Foundation to establish a permanent 1-hectare forest dynamics plot in the SNSM. The plot, established in 2023, gives us detailed data on a tree community in a patch of primary cloud forest around 2200 m asl in the SNSM. The occurrence data is now available on SiB Colombia and GBIF.
Read more about our findings from the plot in our publication in Annals of Forest Science, and see our paper in Annals of the Missouri Botanical Garden for broader contextualization about the floristic uniqueness of the SNSM.
Ongoing work at the plot includes microclimate monitoring and repeated inventories to track demography.
Contamination of Maine lakes by pharmaceuticals and personal care products.
The contamination of surface waters by pharmaceutical and personal care product chemicals (PPCPs) is well-studied in treated wastewater effluent and urban surface waters, but the extent of PPCP contamination in rural areas unaffected by wastewater treatment or industrial runoff is not well understood .
For my undergrad thesis, I explored PPCP contamination in the rural Belgrade Lakes of Maine. We detected a handful of PPCPs, such as caffeine and amphetamine, nearly ubiquitously within and between lakes and across seasons. Although the levels we detected were always very low, they may have significant impacts on the health and behaviors of aquatic biota. Read more in our publication in the Journal of Environmental Studies and Sciences!
