Impacts of California Coastal Scrub Canopy Cover on Drought Resilience in Perennial Grass, Stipa pulchra.
Todd Dawson, Professor
Integrative Biology
Closed. This professor is continuing with Fall 2024 apprentices on this project; no new apprentices needed for Spring 2025.
California’s coastal grasslands, hosting roughly 90% of the state’s rare and endangered life, and 40% of the state’s native vegetation, are an important carbon sink, and a valuable natural and cultural resource. Over the past 150 years, native grasslands have waned in an absence of herbivory and fire disturbance, which historically curtailed encroachment by woody plants, primarily Baccharis pilularis (coyote scrub-brush). Today, added pressure from invasive species only aggravates native grassland decline. To maintain open grasslands, land managers regularly employ mechanical methods to prevent conversion to scrubland. But how grassland species respond to scrub encroachment is poorly understood.
For this project, methods in stable isotope ecology will be used to explore physiological effects of B. pilularis canopy on the dominant native perennial grass, Stipa pulchra. Analysis of Carbon, Hydrogen and Oxygen isotopes preserved within the tissues of S. pulchra can shed light on how coastal scrub impacts the growth, phenology and water relations of this grass.
Role:
Job Description:
Seeking a URAP candidate to manage sample preparation for stable isotope analysis. This preparation will chiefly entail cryogenic distillation of water and the extraction of soluble sugars. Daily tasks may include: sample grinding, weighing, pipetting and extractions; preparation of chemical solutions; assistance during analysis with lab-based methods data collection and data entering into a database (EXCEL).(Duties may also include supervised field collection and transport of samples depending on student interest.)
Learning Outcomes:
Students will acquire proficiency with important methodologies in the extraction and processing of samples for stable isotope analysis. In addition to learning about the chemical and physical processes that drive the patterns found in isotopes ecology, students will also have an opportunity to learn about the ecological theory relevant to this work, including—leaf energy balance, photosynthesis, water relations and community ecology through paper reading and/or discussion. Students interested in pursuing their own independent research may seek future opportunities in the lab, or future positions for field research in the summer.
Qualifications:
Work requirements:
No prior experience required. We are seeking someone who is motivated, detail-oriented, a strong work-ethic and willingness to learn. Students must have the capacity to complete repetitive tasks that require patience and fine manual dexterity. Preference will be given to applicants studying or interested in ecology, plant physiology, or chemistry.
Time requirements:
Because the extraction process can require attentive monitoring, preference will be given to students able to allocate their time in 3-5 hours increments. However, the number of hours the student works per week and how their hours are distributed are negotiable.
Day-to-day supervisor for this project: Gregory Arena, Ph.D. candidate
Hours: 6-8 hrs
Related website: https://nature.berkeley.edu/dawsonlab/
Related website: https://nature.berkeley.edu/stableisotopelab/