Soils of California

About

My name is Iris Holzer (she/her), and I am an Assistant Teaching Professor in the Environmental Studies Program at UC Santa Barbara, where I specialize in soils and environmental chemistry. My research focuses on rock weathering, soil formation, and carbon dynamics in the soils of agricultural and natural systems, including enhanced rock weathering for carbon removal.

I completed my Ph.D. in Soils & Biogeochemistry at UC Davis in 2023. Prior to graduate school, I earned my B.A. in Geology from Scripps College via the Pomona College Geology Department. Born in Mississippi and raised in Missouri, I have loved my last 11+ years learning and teaching across California’s diverse landscapes.

In my teaching and research, I am committed to fostering equitable access to science and the outdoors, particularly via immersive field experiences that prioritize community building, safety, and place-based learning. I was recognized for this work with the UC Davis Chancellor’s Award for Excellence in Mentoring Undergraduate Research in 2022. Now at UCSB, I am working to lower barriers for student participation in field-based opportunities, including by reducing or eliminating costs.

Photo credit: Hibah Ganie

Teaching

Nothing motivates me more than teaching and learning alongside students. Field experiences were transformative for me as an undergrad, and I love getting out into field with classes as much as possible. Across all my classes, I encourage independent inquiry, place-based learning, enthusiasm, and an ethic of care for each other and our world.

The heart of my job is teaching undergraduate courses in soils and environmental chemistry in the Environmental Studies Program at UCSB, where a number of my classes are cross-listed in Geography. Presently, I teach the following courses:

• Principles of Soil Science (ENVS/GEOG 114A)
• Soils of California: Formation, Morphology, and Management (ENVS/GEOG 114B)
• Colloquium on Current Topics in Environmental Studies (ENVS 190)
• Environmental Chemistry sequence (ENVS 15A, 15B, 15BL - starting in 2025!)

Previously, at UC Davis and Pomona, I served as a teaching assistant for courses across soils and earth science:

Whether taking students to describe their first soil pits mere steps from their dorms or teaching about terrestrial carbon storage amidst giant sequoias, I emphasize inclusive, place-based learning that starts with safe field environments. The field continues to be a frequent site of racism, sexism, and ableism. Additionally, unequal support for underrepresented students contributes to hostile exclusion from majors, internships, and jobs. Changing these dynamics requires systematic changes to how we conduct fieldwork, especially from those of us who teach and work with students in the field.

This spring, I secured funding for FieldFutures training for one class. In a post-training survey, 91% of students said they anticipate this training definitely being valuable or useful in their future work. One student shared that the training “provided a lot of information that can be generalized to other aspects of field work such as safety, power dynamics, and following proper protocol”. This created a starting point for class discussions of field safety, communication, and planning, and students shared that they felt newly empowered to ask about field safety plans in upcoming internships, courses, or field-based research.

I am continuing to seek funding to offer these and other kinds of field safety trainings in future courses and to reduce costs of field courses for students. Please reach out if you’d like to chat!

Research

As a soil scientist and biogeochemist, I work at the nexus of geology, agriculture, hydrology, and soil science. My diverse research background has included projects on soil formation in California deserts, groundwater geochemistry in New Zealand, the transport of micro-pollutants at the U.S. Geological Survey, crop uptake of trace metals in North Carolina, and the geochemistry of the Burgess Shale.

At the heart of my research is a desire to better understand weathering — the processes of mineral transformations at the surface of Earth. I am fascinated by the connections between weathering processes and the hydrologic cycle, the movement of elements like carbon through ecosystems, and soil development. I love exploring these topics with students, especially undergraduates, in the classroom, lab, and field.

One major area of focus for me is enhanced rock weathering as a carbon dioxide removal tool in agricultural systems. I began this work at UC Davis with the Working Lands Innovation Center, using field trials across California and smaller mesocosm studies to assess the carbon sequestration potential of enhanced rock weathering, as well as impacts on crop and soil health. You can read more about my research in this paper and a related interview. Another recent paper from our team, led by Dr. Noah Sokol of Lawrence Livermore National Lab, examines the effects of enhanced weathering on soil organic matter.

Beyond studying applications of mineral weathering, I also research weathering in natural systems, including the role of rock-derived nitrogen as a critical nutrient source in terrestrial ecosystems. In the forests of Northwestern California, I look at the release of these nitrogen pools across climates, furthering our understanding of how this essential nutrient becomes available, supporting forest growth and carbon uptake.

I work occasionally as an independent research consultant, including with the research nonprofit CarbonPlan to develop an enhanced weathering quantification tool and explainer and with CV-SALTS via Formation Environmental.

You can find more links to my research on my Google Scholar profile. Stay tuned for upcoming projects with UCSB undergraduate researchers and continued work on enhanced weathering, salinity, and carbon cycling in California.

Contact

You can find my contact info here. I'm always excited to chat about scientific collaborations, undergraduate research projects, courses, or ways to support our field programs.

• Twitter
• Google Scholar
• GitHub

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