Earl S. Tupper Postdoctoral research fellow
Smithsonian Tropical Research Institute
Box 0843-00153, Republic of Panamamartijnslot78[at]gmail[dot]com
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My research is focused on understanding the effects of climate change on the performance of terrestrial plants. Climate change can have major consequences for plant performance, yet our understanding of the mechanisms by which plants may adjust to environmental changes is limited. I study plant growth, physiology and reproduction with the aim of understanding the adaptation and acclimation of plants to their environment. Results from this research improve our ability to predict plant responses to environmental change, in terms of the size and direction of the carbon fluxes between the terrestrial biosphere and the atmosphere, and in terms of shifts in competitive strength among different species within a community in a changing environment.
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New papers in 2018
For every sun leaf there are ~five shade leaves in a tropical forest: can we assume that shade leaves have the same heat tolerance as sun leaves, or are they acclimated to cooler conditions? We found a small, but significant difference in two of the three species, with shade leaves having lower tolerance to heat (early online).
Do increases in temperature during the day or during the night influence growth of tropical saplings? We expected they would, but we found that the species we studied displayed considerable physiological plasticity in response to warming and increases in average night- or day temperatures did not significantly reduce plant growth in any species. Nonetheless, with rising mean temperatures the fluctuations around the mean may cause extreme conditions that will be detrimental to the performance of tropical species.
New papers in 2017
Now online, a new paper on temperature effects on photosynthesis of tropical trees, in which we show temperature responses of Vcmax, Jmax and stomatal conductance for four species. Stomatal conductance peaks at much lower temperatures than the biochemical parameters and our analyses suggest that the decrease in stomatal conductance is the main driver in the decrease in net photosynthesis above current ambient temperatures.
Our paper on acclimation of photosynthesis to (elevated) temperature in tropical tree seedlings shows consistent increases in the optimum temperature for photosynthesis, but no increase in the high-temperature carbon compensation point, leading to narrower temperature response curves for plants grown at elevated temperatures. See the Highlight for this paper by Dusenge & Way here.
New paper, led by Zhang-Hong Tan, uses Eddy Co-variance data to analyze stand-level photosynthesis in relation to temperature across seven tropical forest sites. The temperature optimum of stand-level carbon uptake scales with site temperature. Above the optimum temperature decreases in stomatal conductance drive the decrease in photosynthesis.
A survey of temperature responses of photosynthesis across 42 tree and liana species in two lowland tropical forests, which shows a tendency for convergence of TOpt—the optimum temperature for net photosynthesis—across ecologically divergent co-occurring species, with site-specific temperature optima very similar to mean maximum daytime temperatures.