Dew deposition occurs in ecosystems worldwide, even in the driest deserts and in times of drought. Although some species absorb dew water directly via foliar uptake, a ubiquitous effect of dew on plant water balance is the interference of dew droplets with the leaf energy balance, which increases leaf albedo and emissivity and decreases leaf temperature through dew evaporation. Dew deposition frequency and amount are expected to be affected by changing environmental conditions, with unknown consequences for plant water stress and ecosystem carbon, water and energy fluxes. Here we present a simple leaf energy balance that characterizes the effect of deposition and the evaporation of dew on leaf energy balance, transpiration, and carbon uptake. The model is driven by five common meteorological variables and shows very good agreement with leaf wetness sensor data from the Blue Oak Ranch Reserve in California. We explore the tradeoffs between energy, water, and carbon balances for leaves of different sizes across a range of relative humidity, wind speed, and air temperature conditions. Our results show significant water savings from transpiration suppression up to 25% for leaf characteristic lengths of 50 cm. CO2 assimilation is decreased by up to 12% by the presence of dew, except for bigger leaves in windspeed conditions below 1 m s−1 when an increase in assimilation is expected.
I gave a talk on my current project in collaboration with Pr. Sally Thompson from UC Berkeley looking at transpiration suppression due to fog and dew. I was also very happy to learn more about some fascinating dew and fog collection projects, a topic I have thought about a lot before.
It was great to get to see old friends, like former Caylor Lab member Lixin Wang presenting his work on the use of stable isotopes to separate dew and fog water inputs for vegetation in the Namib desert, or Camille Duprat, former post-doc in the MAE department at Princeton University. In addition, I got to meet some of the most active people in the world of dew related research, like Daniel Beysens, Nurit Agam, Jürgen Burkhardt, and Simon Berkowicz.
Finally, the conference was a unique opportunity to meet young and enthusiastic scientists from all across the world, and I am thrilled for the opportunities that this new network of friends and colleagues will bring in the future!
See the conference website HERE.
See the full conference program HERE.
See the live tweets from the conference using the hashtag #FFCD2016.
PS: Can you find me on the official conference picture above?
Last week, I went out to California to initiate a new collaboration with Pr. Sally Thompson at UC Berkeley. Pr. Thompson has been collecting leaf wetness data at multiple sites across California, and I will be using her dataset together with my leaf energy balance model to estimate the reduction in transpiration associated with dew and fog formation. I got the chance to visit one of the field sites, the Blue Oak Ranch Reserve, located up in the hills above San Jose. See the gallery below to see some pictures of my trip!