New article in Oecologia

Our new article Dew‑induced transpiration suppression impacts the water and isotope balances of Colocasia leaves was just published in a special issue of Oecologia honoring the career of Jim Ehleringer. In collaboration with Paul Gauthier and my PhD advisor Kelly Caylor, this paper looks at the effects of dew deposition on the isotope composition of Colocasia esculenta leaf water. See the abstract below for a quick overview of the study and results or head over to Oecologia’s website to read the full paper.Abstract

Foliar uptake of water from the surface of leaves is common when rainfall is scarce and non-meteoric water such as dew or fog is more abundant. However, many species in more mesic environments have hydrophobic leaves that do not allow the plant to uptake water. Unlike foliar uptake, all species can benefit from dew- or fog-induced transpiration suppression, but despite its ubiquity, transpiration suppression has so far never been quantified. Here, we investigate the effect of dew-induced transpiration suppression on the water balance and the isotope composition of leaves via a series of experiments. Characteristically, hydrophobic leaves of a tropical plant, Colocasia esculenta, are misted with isotopically enriched water to reproduce dew deposition. This species does not uptake water from the surface of its leaves. We measure leaf water isotopes and water potential and find that misted leaves exhibit a higher water potential and a more depleted water isotope composition than dry leaves, suggesting a ∼30% decrease in transpiration rate compared to control leaves. We propose three possible mechanisms governing the interaction of water droplets with leaf energy balance: increase in albedo from the presence of dew droplets, decrease in leaf temperature from the evaporation of dew, and local decrease in vapor pressure deficit. Comparing previous studies on foliar uptake to our results, we conclude that transpiration suppression has an effect of similar amplitude, yet opposite sign to foliar uptake on leaf water isotopes.


New paper out in pre-print

After thinking a lot about pre-print and how they fit in the world of plant research, I have decided to give it a try! My first pre-print entitled “Dew-induced transpiration suppression impacts the water and isotope balances of Colocasia leaves is now available on the bioRxiv: see the article!

The paper examines the effects of dew on transpiration suppression in Colocasia esculenta leaves using stable isotopes of water to track changes in the water status of the leaves. The article has been submitted to a peer-reviewed journal.

Abstract: Foliar uptake of water from the surface of leaves is common when rainfall is scarce and non-meteoric water such as dew or fog is more abundant. However, many species in more mesic environments have hydrophobic leaves that do not allow the plant to uptake water. Unlike foliar uptake, all species can benefit from dew- or fog-induced transpiration suppression, but despite its ubiquity, transpiration suppression has so far never been quantified. Here, we investigate the effect of dew-induced transpiration suppression on the water balance and the isotopic composition of leaves via a series of experiments. Characteristically hydrophobic leaves of a tropical plant, Colocasia esculenta, are misted with isotopically enriched water to reproduce dew deposition. We measure leaf water isotopes and water potential and find that misted leaves exhibit a higher water potential (p < 0.05) and a more depleted water isotopic composition than misted leaves (p < 0.001), suggesting a ∼30% decrease in transpiration rate (p < 0.001) compared to control leaves. We propose three possible mechanisms governing the interaction of water droplets with leaf energy balance. Comparing previous studies on foliar uptake to our results, we conclude that transpiration suppression has an effect of similar amplitude, yet opposite sign to foliar uptake on leaf water isotopes.

https://www.biorxiv.org/content/early/2017/08/30/178293
doi: https://doi.org/10.1101/178293


SPATIAL Short Course at the University of Utah

I just came back from the SPATIAL Short Course, organized by Gabe Bowen at the University of Utah. Morning lectures were focus on the theoretical underpinnings of spatial structure in a range of isotopic systems and how these are applied to address scientific challenges in multi-scale ecological, biogeochemical and Earth science research. Afternoon laboratory sessions introduced us to tools and techniques for working with spatially explicit environmental datasets, including geodata identification, acquisition, management, and analysis, using real data from published and unpublished sources.

Lecturers included John HayesJason West, Chris Still, David Noone, Simon Brewer, John Lin, Jed SparksJim Ehleringer, Rebecca PowellDiane Pataki and Jason Neff. You can also have  look at the presentations we produced after each week of afternoon labs HERE.

Beyond the lectures and labs, the course was a great way to meet graduate students and post docs working in my field and I am excited to develop new collaborations and projects with them!


SPATIAL 2014

I just got accepted to the SPATIAL 2014 Summer course at the University of Utah. This course is the second leg of the Iso-Camp Summer school I attended in June 2013. SPATIAL is focused on regional and continental research involving stable isotopes. In addition, I also got awarded a $2300 NSF scholarship to cover the tuition of the course.

I am very excited and I am really looking forward to being back in Salt Lake City to hang out with the isotopeteers!


AGU Fall Meeting 2013

I presented two posters at the AGU Fall Meeting 2013, held in San Francisco this past December.

My first poster presented my work on the evolution of vapor and rain isotopic composition during 17 rain storms in Summer 2012 in Central Kenya.

See the poster.

The second poster presented my current project with Adam Wolf on plant physiology  under drought and water theft. I presented the first results of our rainout experiment conducted last summer at Silas Little Experimental Forest in NJ. The experiment will be reconducted in Summer 2014.

See the poster.


First International Workshop on Advances in Observations, Models and Measurements Techniques of Atmospheric Water Vapor Isotopes

I gave a presentation at the First International Workshop on Advances in Observations, Models and Measurements Techniques of Atmospheric Water Vapor Isotopes hosted at the CNRS (French National Center for Scientific Research) in Gif-Sur-Yvette, near Paris, from October 16th to October 18th 2013. My talk presented the first results of her project on rain-vapor equilibrium in Central Kenya.

The workshop was organized by Hans Christian Steen-Larsen and Valérie Masson-Delmotte and had been designed to bring together the community involved in measurements and modeling of water vapor stable isotopes in order to review the state of the art, to stimulate new collaborations, and to formulate recommendations for future research. It was decided to write a white paper highlighting the added-value of isotope measurements for atmospheric science studies, the state of the art for each topic, the progress in different research directions allowed by recent water vapor isotopic composition measurements, and key recommendations.

Workshop’s website

My presentation