SES is a semester long intensive program where undergraduates take courses, have weekly day-long labs, and process and analyze collected data and present it for 9 weeks. After those nine weeks, student lead an independent project on their topic of choice in environmental science. For the third year in a row, I led the canopy scaling field and data activities. This year, the weather could not be nicer, though we dealt with some herbivory and temperature issues for getting optimal photosynthesis values - such is the challenge when measuring in September on Cape Cod!
Last year, I integrated a fluorescence element to the lab, and we used a WALZ PAM Jr to take light response curves of sun-adapted leaves and observe the response of non-photochemical quenching and yield of photosystem II at different light intensities in sun and shade leaves.
Students excelled at these tasks, despite a wonky LiCor 6400 (one was perfect, one gave us trouble) and hot temperatures. The rest of the week we went over scaling equations and discussed the different aspects of photosynthesis and how fluorescence and CO2 concentrations can be measured by different pieces of equipment to inform our ideas!
In May, I was asked to contribute a chapter for a book on pedagogy in Environmental Science undergraduate courses and the integration of EcoJustice. This task made me think deeply about values and how they can be not only taught, but modeled and explicitly discussed and practiced in science classrooms.
What do scientists value? How can we demonstrate those values in undergraduate courses?
To answer these questions, my chapter focuses on five 'scientific values' I identified through my experiences and through a informal survey of scientists at Ecosystems Center at MBL:
If scientists (especially scientists who are also teachers of undergraduates) place value on these aspects of their practice, how can this be demonstrated and discussed in the classroom? In this chapter, I promote the idea that they be integrated into the course design: assessments, activities, discussions, rubrics, etc. EcoJustice - a theme of the book - stands for inclusion of diverse ideas, equity, and sustainability. It was a personal challenge to weave these themes together, but the more I worked on it, the clearer it became in my mind.
How do you promote equity and inclusion in an Environmental Science classroom when you are talking about biogeochemistry of forests? Practice these values through collaboration and communication: discussions in the classroom can be arranged to ensure all student voices are promoted and listened to, ideas are constructively critiqued with different perspectives and goals in mind. Do not allow lazy classrooms where only the presenter is made to have an opinion. Keep students highly involved in the direction of the class.
As a teacher, with each year I realize more and more that I am an informed guide to learning, not a dictator on content and its presentation. Student learning requires individual agency. Students learn so much more through making mistakes, traveling down their own rabbit holes of inquiry, and being driven by their own interests within the sphere of a topic, than they do being lectured to for 3 hours a week. So my goal as an educator is to think of new ways (with the students - nothing behind the scenes!) to guide their learning.
Writing about these topics was surprisingly fun, and really brought me back to teaching high school. It is heartening to read about how undergraduate biology programs are being restructured to be more student-driven and inclusive and creative. While that was not my undergraduate experience, I can only assume it will draw more students who may be timid about biology (and science in general) to take the plunge and learn about the natural world in college.
In the past 6 months, two papers have been published discussing nuances of the "Kok method", which uses measurements of high resolution low-light curves to detect the degree of inhibition of respiration by light. I have worked extensively with this method for my graduate research in the Arctic, and more recently in deciduous hardwood canopy species at Harvard Forest.
The first paper, by Farquhar and Busch approaches the method with concern that the acceleration of the quantum yield at very low lights is controlled by the change in chloroplastic CO2 concentration, and not a signal of a relaxation of inhibition at low light.
In response to these claims, a paper by Buckley, Vice, and Adams, applied the Kok method in young and old leaves under two measurement O2 concentrations, and used this data for evidence to oppose the claims made by Farquhar and Busch. Primarily, Buckley, Vice, and Adams show that the breakpoint and the acceleration of quantum yield at low light cannot be explained fully by just changes in chloroplastic CO2 concentrations, but rather is tied to respiration. However, the note the importance of accounting for cc when using this method, and voice concern about it's broad application.
These papers follow a vigorous discussion about respiration in the light that has resulted in two more recent publications led by Guillaume Tcherkez in New Phytologist: one describing the workshop last summer in Angers, France (that I am grateful to have attended), and another that reviews the state of respiration in the light using multiple approaches.
This active (and all polite and open-minded!) exchange of ideas in New Phytologist promotes the ongoing challenge of how to deal with respiration in the light in leaves, and also in whole canopies. The application of the inhibition in models can have large consequences for how we think about carbon exchange at different scales.