Seeking a PhD student to work on a new NSF-funded project with field work on a Southern California river (Santa Clara) plus dendro-isotope lab analyses. Three years of funding minimum available, with additional years possible.
*PROJECT TITLE* Linking basin-scale, stand-level, and individual tree water stress indicators for groundwater-dependent riparian forests in multiple-use river basins *THE POSITION AND HOW TO APPLY* The PhD position is supported at SUNY-ESF, the State University of New York College of Environmental Science and Forestry, working with Dr. John Stella and interdisciplinary collaborators at UC Santa Barbara and The Nature Conservancy. The position will start in fall 2017. Research questions will focus on riparian ecosystem response to drought, climate change and groundwater extraction. Methods will include field sampling to inventory riparian forest structure and health, collecting and analyzing tree rings for growth trends and annual water use efficiency using carbon isotopes, and assessing critical thresholds for riparian forest decline. Field studies will occur in the Santa Clara River basin in Southern California with lab work at SUNY-ESF and partner institutions. Ideal candidates will have an MS in ecology, environmental science, or a related field; a strong quantitative and statistical background; the ability to work in remote field settings; and interest in riparian forest ecology and tree ecophysiology in dryland regions. The position is funded for a minimum of three years and provides a competitive stipend, tuition and benefits. Interested candidates should send a CV/resume (with GPA and GRE scores), a description of research interests and experience, and names and contact information for 3 references to [email protected]. For more information on how to apply, see http://www.esf.edu/fnrm/stella/opportunities.html *FULL PROJECT ABSTRACT* Linking basin-scale, stand-level, and individual tree water stress indicators for groundwater-dependent riparian forests in multiple-use river basins John Stella, SUNY-ESF (PI); Michael Singer, UCSB (PI); Dar Roberts, UCSB (Co-PI) This project will develop a suite of water stress indicators at several scales to assess the health of riparian ecosystems in response to sustained groundwater decline. Riparian forests and woodlands are hotspots of biodiversity and support key functions and habitats within river corridors, but they are particularly sensitive to large changes in water supply. The study will take place in the Santa Clara River (California, USA), where sustained groundwater pumping for irrigation during a severe drought has had negative impacts and allows for study of riparian woodland response to short- and long-term climate change. The project team will assess the signals and thresholds of water stress over the last decade using high-resolution aerial imagery and tree-rings to develop predictors of long-term impairment and collapse. This work addresses a topic of urgent scientific and societal importance, namely how to assess and prevent negative impacts of drought and human-induced water shortages on vulnerable, high-value riparian ecosystems. In collaboration with The Nature Conservancy, the project team will integrate results within statewide guidelines for protecting groundwater-dependent riparian ecosystems mandated under California’s recent Groundwater Sustainability Management Act. The project will engage the public in several ways, including: 1) consulting with groundwater managers, farmers and other stakeholders through workshops to develop effective methods for communicating results widely; (2) mentoring early career scientists including women in STEM subjects; and 3) engaging with K-12 student programs in diverse local communities to increase environmental awareness in the Santa Clara basin. As water management in multiple-use river basins around the world becomes increasingly intertwined with large-scale ecosystem restoration, the proposed research sits at the forefront of broader human-climate-ecosystem challenges facing societies, businesses, and governments. The project will capitalize on extensive groundwater well records to link water table dynamics with changes in plant water status detected at two different scales: (1) basin-wide, high-resolution aerial imagery taken seasonally during the drought; and (2) annual growth and carbon isotope data from tree rings covering the same period. The study is novel, in that it integrates advanced methods in two rapidly-emerging fields, hyperspectral remote sensing and isotope dendroecology, in developing a holistic understanding of water stress at multiple scales of resolution. The research is also potentially transformative in that it compares water stress indicators that vary in their timing, strength, and rates of change, and that it enables the assessment of warning signs and time lags between reduced growth and functioning in individual trees, and synoptic forest decline evident throughout a river corridor. These findings will have broad application beyond the study system, because the ecology and functional roles of riparian trees are similar in many water-limited regions, with similar foundational importance in groundwater-dependent ecosystems globally.
