Grant A. Harris fellowship (2020 recipients)


  • 2020 recipients

  • Peter A. Tereszkiewicz
    Peter A. Tereszkiewicz –  University of South Carolina

    Award:  NDVI and PRI SRS sensors, ZL6 data logger and ZENTRA Cloud

    Quantifying Seasonal Vegetation Controls on Coastal Dune Volumetric Change

    Coastal dunes—located on the subaerial beach—provide a formidable barrier to storm surge and flooding that protect coastal communities from economic loss. Vegetation-sediment interactions mark a keystone component to understand coastal dune growth and post-storm recovery. Notwithstanding this importance, traditional methods of monitoring vegetation have resulted in data inconsistencies and qualitative assumptions. The year-long field study proposed here will use NDVI and PRI SRS sensors to spectrally monitor dune vegetation concurrently with in situ digital erosion pins (DEPs). For the first time vegetation and erosion-accretion dynamics will be measured at the same sampling resolution, marking a momentous advancement in coastal geomorphology.

    The interplay of wind, sediment, and vegetation sculpt dune features via aeolian (wind- blown) processes (Sherman, 1995). Vegetation induces turbulence into the wind field disturbing sediment transport, and often, facilitating deposition and dune growth (Hesp, 1981). Traditional methods for assessing dune vegetation has either relied on qualitative estimation of vegetation quadrats (Stalter, 1974; Kim and Yu, 2009) or solely captured spatial properties of vegetation density via photographs (Gillies et al., 2002; Renkin, 2015). These methods make it difficult to develop a continuous time series of vegetation data, and often leaves researchers with temporal snapshots of vegetation variability.

    The primary objective of this study is to quantify the influence seasonal vegetation density and health has on dune volumetric change. 

    This study will introduce a new methodology to coastal geomorphology using NDVI and PRI SRS sensors to quantify vegetation density and stress. The creation of a continuous vegetation dataset paired with in situ erosion-accretion measurements will aid in understanding vegetation-sediment interconnectedness and dune formation.

  • Jaclyn Fiola
    Jaclyn Fiola –Virginia Tech

    Award:  SATURO infiltrometer, TEROS soil moisture sensors, ECRN-100 rain gauge, ZL6 data logger and ZENTRA Cloud

    Pausing precipitation: innovative methods to limit rain infiltration into vineyard soils

    The wine industry in Virginia often suffers from excess soil water availability, which can negatively impact wine quality. We propose to use METER instruments to test several infiltration-reducing compounds for their ability to reduce the amount of water entering vineyard soils. Limiting infiltration should improve grapevine growth and fruit quality for winemaking, and could transform grape growing in high-precipitation winemaking regions of the world.

    Significance of Research: As of 2015, Virginia was #8 in the United States for vineyard hectarage, and had an economic impact of $1.37 billion.

    1 Virginia receives an average of 108.4 cm of precipitation annually, with the highest rainfall during the months of May, July, and August.

    2 This high rainfall translates to excess water availability in many Virginia vineyard soils which can produce vigorous vine growth (e.g., destabilize the balance of vegetative growth to crop development) and be detrimental to fruit quality. Winegrape quality is positively impacted when mild water deficits limit vine growth, especially in wet climates such as Virginia. Grape growers in this region are eager to reduce soil water, especially during excessively wet years, and there are no economical and sustainable methods currently available.

    Many strategies have been tested to reduce vineyard soil water such as tile drainage, cover crops (to compete for water), and plastic soil covers. However, these interventions all have limitations ranging from high costs of tile drain installation to the often-negligible net water use by cover crops to the negative environmental impacts of plastic waste. Compacting soils to limit rain infiltration has also been proposed, but could prevent evaporation from soil and may create issues with drainage, root respiration/gas exchange, and erosion.

    Goals & Objectives: The ideal vineyard soil water intervention would limit infiltration into the soil while minimizing erosion and allowing vapor and gas exchange. To achieve this ideal intervention, we propose to test several environmentally-friendly polymeric compounds developed by the transportation industry to decrease infiltration into soil: DirtGlue (Salem NH) and Soiltac (Soilworks, Scottsdale AZ). We will also test stearic acid, a naturally occurring hydrophobic fatty acid, which can reduce infiltration while enhancing water vapor losses from soil.4 Such compounds have not been tested as a way to control soil water within vineyards. Our goal is to compare the effectiveness of soil-applied compounds for reducing infiltration into soils, then quantify the impacts on grapevine growth and fruit quality.

  • Daniel Hastings
    Daniel HastingsUniversity of California, Santa Cruz

    Award: TEMPOS thermal properties analyzer, SC-1 leaf porometer, TEROS 21 water potential sensors, TEROS 10 soil moisture sensors, ZL6 data logger and ZENTRA Cloud.

    Is Underground Water Storage a Key to Joshua Tree Survival?

    The Joshua tree, an icon of the American West, is threatened by climate change. While some aspects of Joshua trees have been well-studied, we have a limited understanding of their water management under periods of extreme water stress. The objectives of this research are to

    1) evaluate the role of water storage in Joshua tree water budgets,

    2) document the yearly fluctuations in water storage in the tissues of Joshua trees, and

    3) develop an integrated model of Joshua tree anatomy and water relations to simulate whole-plant hydraulic responses to different climate conditions.

    These data can be used to model future Joshua tree distributions, inform conservation planning and assisted migration efforts, and improve our understanding of ecohydrology in the Mojave Desert.

    The Joshua tree is a charismatic species and a vital economic force attracting visitors to its popular namesake national park. It is also a foundational species that provides services to Mojave Desert ecosystems. Climate change is expected to reduce Joshua trees to 10% of their current range due to increased temperatures and more frequent drought1. Although much is known about the natural history of Joshua trees, we do not know much about their water budgets. Understanding water storage and its fluctuations in Joshua trees, both on daily and annual scales, will give us new knowledge about how they may respond to individual and successive droughts.

    Initial Results: Observations and microCT of Joshua tree roots and a drought study imply that water storage does not occur in the stem as expected, and may occur in specialized root tissues.

    Hypotheses: (H1): Joshua tree tissue water content, water potential, and transpiration will fluctuate daily and annually in a manner that reflects their usage of both soil water and plant water storage. (H2): The transpiration of Joshua trees includes water that was stored in speicalized tissues in the roots. (H3): Joshua trees will require several precipitation pulses following long periods of dry conditions to replenish water in storage tissues to full capacity.

  • Natalie M. Aguirre
    Natalie M. Aguirre – Texas A&M University

    Award: SC-1 leaf porometers, PAR sensors, a ZL6 data logger and ZENTRA Cloud

    Investigating the Relationship Between Plant Priming and Stomatal Conductance

    Herbivores often invade agricultural fields and can lead to devastating yield losses. Following an attack, plants emit characteristic blends of herbivore-induced plant volatiles (HIPVs), which play important roles in plant defense. Recently, it has been discovered that plants also perceive and respond to HIPVs. Some plants detect HIPVs emitted by their damaged neighbors and respond by enhancing their own defenses in preparation of future attack, known as priming. Defense priming has been documented in a wide range of plant species, including several agriculturally important crops like maize and cotton. However, little attention has been given to the physiological basis of this process.

    In general, plant gas exchange occurs through stomata, and calculations indicate that volatile compounds can enter the plant through stomates in light conditions4. Two major unanswered questions in plant defense priming are:

    1) how do plants take up volatile compounds for priming? 

    2) how does plant exposure to volatile compounds influence physiological processes like gas exchange?

    No previous research has considered the physiological implications of plant defense priming. Improving our understanding of plant responses could reveal new strategies for enhancing plant resistance to pests.

    Goals and Objectives

    The goal of this project is to use the SC-1 Leaf Porometer to

    1) determine if stomatal openings are required for plant priming by HIPVs and

    2) determine whether plant priming via HIPVs influences stomatal conductance. We predict that HIPVs enter plant leaves through stomates and that successful priming will be positively correlated with stomatal conductance.

    Additionally, if priming cues are taken up through stomata, plants might increase stomatal conductance to increase their access to information while on high alert. Previous work from our lab found a positive correlation between priming and exposure dose5. Further, since plant investment in defenses requires carbon stores and energy, we also predict that plant exposure to HIPVs influences regulation of stomatal conductance to enhance plant gas exchange and photosynthesis.

  • Ryan C. Hodges
    Ryan C. Hodges – Utah State University

    Award: PARIO soil texture analyzer and a WP4C water potential lab instrument

    Soil genesis across a climo-lithosequence of western Haleakalā

    There is enormous climate variability (200 to >2000 mm in precipitation) and soil diversity (seven soil orders of Soil Taxonomy) on the northern and western slopes of Haleakala volcano on the Hawaiian island of Maui. This little studied area provides an ideal location to investigate the influence of climate and volcanic ash on soil development on basalt lava flows. In addition, as land use on Maui shifts from monocultures of sugarcane to livestock grazing and ecotourism, there is growing interest in sequestering soil carbon and developing markets for niche specialty crops. Sampling sites (19) were selected based on similar geology and relief, and were manually excavated, described, and sampled by genetic horizon for a full suite of laboratory analyses. We expect high variability in nutrient and water holding capacity, elemental loss, and carbon content due to the presence of cinder cones across the study site. Findings will help determine the distribution of these ash-influenced soils, and can advance our understanding of soil development while providing useful soil information for land managers.

    Primary Goals and Objectives: Our goals are to determine the influence of precipitation and volcanic ash on the morphology, mineralogy, and composition of soils across a climatic gradient of western Haleakalā. This will enable us to model the relationships between precipitation, temperature, weathering stage, mineralogy, and elemental loss of these volcanic soils (Chadwick et al., 2003; Chorover et al., 2004).

  • Karly Soldner
    Karly Soldner – Drexel University

    Award: ATMOS 41 all-in-one weather stations, Infrared radiometers, ZL6 data loggers and ZENTRA Cloud

    Combatting urban heat stress with small-footprint green stormwater infrastructure in Philadelphia’s most heat-vulnerable neighborhoods

    In Philadelphia and other urban areas, the urban heat island (UHI) effect exacerbates the risks associated with extreme heat due to heat-absorbing surfaces and limited vegetation. This impact is not equally distributed over the urban landscape but concentrates in areas with heightened levels of heat absorbing materials and reduced tree cover. Surface temperature maps identify some neighborhoods as hotter on average than other areas, sometimes differing by as much as 8 °F. These warmest neighborhoods are disproportionately inhabited by people of color and people experiencing poverty.

    Philadelphia’s climate is expected to warm steadily over the coming century, with four to ten times as many 95+ °F days expected per year by 2100. This increase in extreme heat events is projected to result in six times as many heat related deaths.

    One resource used to combat the urban heat island effect is green infrastructure. Philadelphia hosts a long-term green infrastructure plan that utilizes decentralized environmental assets that mimic the ecology of the pre-development landscape with the goal of reducing pollution from urban stormwater. Restoring the natural ecological processes of the land cover includes reduction of the impervious surfaces that also retain heat and reintroducing vegetated space, further reducing temperatures through evaporative cooling.

    Philadelphia’s green infrastructure plan, called Green City, Clean Waters, is housed within the Water Department and serves primarily to reduce combined sewer overflows. This tight focus on a single goal underutilizes the green infrastructure network, neglecting to consider impacts on urban heat. The co-benefits of using green infrastructure designed primarily for stormwater pollution reduction to mitigate the urban heat island effect are not well understood. By sensing temperature differences in and around a green infrastructure site, this study seeks to better quantify the impact of small footprint green infrastructure designed to reduce stormwater pollution on urban surface and air temperatures.