Four graduate students were selected to receive this year’s Mary and Randall Hack ’69 Graduate Award in support of their innovative research on water and water-related topics with implications for the environment. The 2015 recipients are Jesse Ault from the Department of Mechanical and Aerospace Engineering, Joshua Daskin and Mingzhen Lu from the Department of Ecology and Evolutionary Biology, and Benjamin Schaffer from the Department of Civil and Environmental Engineering.
Each year the Hack Award provides research funding to support Princeton graduate students in research from a wide range of disciplines, including climate science, engineering, and environmental policy. The unifying factor is that each project must be focused on the common link of water-related topics with environmental implications.
Each of the students were selected based on the quality of their proposed research, strength of faculty recommendations, proven accomplishments including peer-reviewed publications and awards, and financial need for independent research.
Below, the recipients describe their research and how they plan to utilize the funding from this award.
Jesse Ault’s doctoral research focuses on experiments and simulations used to study poorly understood fluid flows. As a result he is proposing a new system for high-efficiency, evaporative water purification.
Using superhydrophilic porous materials Ault said it’s possible to create a “high-surface-area, low-flow-rate, continuous thin-film flow of water.” Gravity and capillary forces, he said, will wet the materials and drive the flow, which makes it an “extremely high efficiency system.” The only energy input the system needs is for a small pump and fans that help facilitate the evaporation and the collection of water. Because the flow rate will be continuous, contaminates won’t form and clog the system, said Ault.
“We believe these characteristics make this proposed system a strong candidate for real application in water purification,” said Ault. “Namely, the system is highly-scalable, stable, reliable, and it has the potential to purify water at a high efficiency.”
Ault will use the Hack funding to purchase lab materials and equipment and to participate in a major water conference this fall.
Joshua Daskin will study what may be “the most threatened wetlands in the greater Everglades ecosystem.”
According to Daskin, rare scrub environments in central Florida provide habitats for up to 17 amphibian species, several fish, and a whole host of invertebrates. Daskin said that Florida scrub contains “one of the highest concentrations of both threatened and endemic species in the U.S., including dozens of plants and animals that only occur there.”
With support received from the Hack Award, Daskin said he will combine observational and experimental studies to examine human impacts due to climate change and altered fire regimes on threatened seasonal ponds in these scrub habitats.
“Much is known regarding the impacts of fire on terrestrial scrub species, but no work has focused on fire and aquatic species in scrub ponds, despite the high density of these habitats in central Florida,” said Daskin. “I hypothesize that shorter hydroperiods and longer time-since-fire will reduce the density of amphibians, invertebrates, and plants.”
Hack funding will allow Daskin to take two trips to the Archbold Biological Station in south-central Florida and will also pay for sampling equipment plus chemical analyses of pond water.
“Climate change and a future with lower rainfall pose an additional threat to Florida scrub, on top of extensive suburban development and altered fire regimes that have already reduced the extent of scrub habitats upwards of 85 percent,” said Daskin. “My research will help determine how wetland communities in one of the nation’s rarest ecosystems will react to these coincident threats.”
For his dissertation research, Mingzhen Lu is attempting to solve the “major unresolved puzzle” of how nutrients and biogeochemical cycles structure land ecosystems in Western Cape Province, South Africa.
“The South African fynbos biome occurs on some of the most nutrient-poor soils in the world and the plant community has evolved specialized adaptations to low-nutrient conditions,” said Lu. “What is both puzzling and scientifically unresolved is that fynbos plant communities occur interchangeably with native South African temperate forests across the Cape Floristic bioclimatic region as alternative stable states over both ecological and evolutionary time.”
According to Lu, this raises fundamental questions about the mechanisms that maintain the separation between fynbos and forest, and he proposes that nutrients “play the pivotal role in creating and maintaining this dichotomy.”
Lu will use his Hack funding to support two fieldwork visits to Western Cape Province, where he will analyze the nutrient loss from stream water in 30 pristine mountain catchments, which feature high seasonal rainfall in the western part and low seasonal rainfall in the eastern part. He will address how pathways of nutrient loss depend on rainfall seasonality.
“I expect to find an increase of nutrient export in dissolved organic form and decrease of nutrient export in particulate form from intensive winter rainfall in the west to the mild all-year-round rainfall in the east,” said Lu. “I will later incorporate the empirical data from this fieldwork into a theoretical model that I have developed, addressing how the complex interaction of hydrological nutrients loss, fire, and plant root adaptations will generate the ecosystem level fynbos-forest bi-stability.”
At the heart of Benjamin Schaffer’s research is the development of theoretical models that examine the relationship between soil moisture and vegetation biomass, particularly in semi-arid ecosystems like savannas where the availability of water is the primary factor in limiting growth and determining which vegetation species are present and in what amounts.
Key to Schaffer’s research is the way plant physiology and water uptake influence the rate at which moisture is extracted from the soil, which in turn moderates the assimilation of new biomass from atmospheric carbon through photosynthesis. This work involves accounting for varying plant behaviors and strategies, such as stomatal regulation, rooting behavior, and biomass allocation.
“Ultimately, I am interested in employing such models to investigate inter-species competition, with a focus on notions of evolutionary optimality and stability, and long-term coexistence of multiple species,” said Schaffer, who plans to use his Hack funds as summer stipend support. “The focus will not be on detailed modeling of specific landscapes, but rather to develop a strong theoretical basis for the climatic, physiological, and behavioral archetypes that can be used for understanding the general properties of water-limited ecosystems.”