Teaching about the essence of soil biodiversity
Loren B. Byrne, Professor of Biology and Environmental Science, Roger Williams University, Bristol, RI USA
Ahhh, early September already! In many areas of the northern hemisphere—including Rhode Island where I live—this is when summer is winding down with shorter days, continuously singing insects, and for some, the end of endless free time due the beginning of a new school year. Like many professors at teaching-focused institutions, I’m starting the fall semester with a bittersweet mix of apprehension and excitement for the unknowns and possibilities of working with a new group of students.
In particular, I’m looking forward to teaching soil ecology again (an every-other-year class for me). It’s one of my favorite courses because of the content—of course!—but also because it always generates significant learning experiences for students. The existence of a large soil education gap in most people’s education means that much of what students encounter in a soil ecology class is brand new to them. A semester-long exploration of soil biodiversity and soils as complex environmental systems provides a novel opportunity to learn about organisms, processes, ecological patterns and social-environmental issues that aren’t talked about much, if at all, elsewhere in the curriculum.
This semester I’m approaching my soil ecology class with a new-found focus on what I have recently described as “the essence of soil biodiversity: its complex ecological webs and emergent ecosystem services that support aboveground life and human well-being” (Byrne 2022). I have always started the course with a discussion about soil ecosystem services to help students immediately see why the rest of the course’s topics are important (an example syllabus can be downloaded here). However, that theme hasn’t continued through the whole course as much as it could and maybe should. This semester, I will try to pay more attention to helping students continuously connect topics back to the question of “why care?” in context of society’s well-being and sustainability. Hopefully this will help them develop a more integrated view of soils and their biodiversity as essential parts of healthy, thriving human communities—and further, that soils themselves can even be examined as complex social-ecological systems (Byrne and Szlavecz, forthcoming).
Soil ecology students engage in a soil organism scavenger hunt to learn about the diversity of life in soils. Photo credit: L. Byrne.
Such topical content is only one aspect of any course’s story. Another key factor is the methods—the pedagogy—through which students engage in the learning process. Hearing lectures and even looking through microscopes aren’t enough to generate significant, long-lasting knowledge. Thankfully, soils lend themselves well to creative, easily accessible and adaptable lessons. The goal of soil ecology education should be to “invite students into the soil” and have them experience, first-hand, the mystery, wonder, and joy of interacting with soil life. The GSBI’s and Soil Ecology Society’s education websites are great places to find resources.
As a long-time advocate of learner-centered teaching (Byrne 2016), I have developed many hands-on activities for my soil ecology class that I think help students better understand the essence of soil biodiversity. Some of my favorites include:
· A “soil critter” scavenger hunt in a forest at the very beginning of the course, when students find as many soil organisms as they can even if they can’t identify them by taxonomic name yet;
· Dissecting a soil cube (25cm^3) (literally ripping it apart!) sampled from an old field or lawn to see how plant roots and macroinvertebrates exist in a matrix of soil aggregates and pore spaces, and also develop a “feel” for the soil habitat;
Students dissect their soil samples to experience the soil habitat first hand. To support focusing on the activity and personal reflection, it’s structured as an individual activity with wide spacing among students. Photo credit: L. Byrne
· Having students play the role of “professor for a day” for which they have to prepare a full class lesson for their peers about a taxonomic group of soil organisms;
· An ecological web role playing activity (Byrne 2013, pdf here) in which students, acting as their assigned organism (or abiotic resource), have to find and “consume” their food (other students, or “be eaten” by other students) in the room and then collectively draw a web diagram of the relationships they created (also see an expanded version of this activity by Baum and Thiet (2016)).
Such activities exemplify “pedagogy for the pedosphere” (Byrne et al. 2016, pdf here), a phrase that emphasizes the need to expand soil ecology educational materials and methods to foster society’s soil ecological literacy and sustainable soil management. To that end, I’m excited to be teaching soil ecology this fall because I want to try some new ideas to help students think more critically and deeply about the essence of soil biodiversity. Using untested pedagogical activities generates apprehension too, but I’m optimistic that the following visions, though they only now exist in my imagination, can lead to interesting teaching-learning moments:
· A simple “root ball” experiment with small pots to grow plants from seed in sieved sediments (alongside a no-plant control) to see first-hand how roots bind up soil and help form soil aggregates (maybe with earthworms added to some?); this was inspired by my own observations growing seedlings for my garden this year, when I pulled one of them out of the pot (see image);
Growing seedlings in a small part can reveal how roots help bind soil particles into aggregates and start discussions about the rhizosphere. Photo credit: L. Byrne
· Having students create and care for “mini compost bins” (similar to how young students care for eggs and bags of flour) that they watch develop over a few weeks, hopefully with thriving populations of mites, isopods, worms, and surely some fungal hyphae, alongside interesting changes to the detritus;
· Field work to compare invertebrate communities between rewilded and still-used parts of a golf course with a discussion about the roles of soil organisms in urban restoration projects (Byrne 2021);
· A “spirited” brainstorming session about whether and how people might appreciate soil biodiversity more by invoking connections between soils and spirituality, including but not limited to religion (Winiwarter and Blum (2006); also see here and here).
Some other topics that I don’t yet have novel pedagogical ideas for but are relevant to developing holistic knowledge about the essence of soil biodiversity include:
· Mutualisms and competition in soil communities
· How soil organisms affect C & N cycling
· Relationships between soil organisms and disease ecology
· Effects of pollutants on soil organisms and how organisms remediate pollutants.
I’m sure readers of this blog will be able to add many more topics to this list. That’s relatively easy. The bigger challenge for the soil science community is to create learner-centered teaching activities that help students—of all ages and backgrounds—increase their soil ecological literacy. Because the soil education gap is so wide, this needs to be a large, concerted group effort.
How do you help others appreciate soil biodiversity and its benefits to humanity? Please consider publishing your ideas (e.g., formally in journals or informally via an entry for this blog) so that other educators can benefit from your ideas and experiences. When I teach soil ecology next time, I’d love to find your resource listed on the GSBI’s education webpage and use it in my class!
References
Baum, J., R. Thiet. 2016. Using soil organisms to explore ecosystem functioning, services, and sustainability. Pp. 97-103 in L. Byrne, ed. Learner-Centered Teaching Activities for Environmental and Sustainability Studies. Springer: New York.
Byrne, L.B. 2013. An in-class role-playing activity to foster discussion and deeper understanding of biodiversity and ecological webs. EcoEd Digital Library.
Byrne, L.B. 2016. Learner-Centered Teaching Activities for Environmental and Sustainability Studies. Springer, New York.
Byrne, L.B., R.K. Thiet, V.B. Chaudhary. 2016. Pedagogy for the Pedosphere. Frontiers in Ecology and the Environment 14: 238-240.
Byrne, L.B. 2021. Socioecological Soil Restoration in Urban Cultural Landscapes. Pp. 373-410 in: J.A. Stanturf and M.A. Callaham, eds. Soils and Landscape Restoration. Wiley Publishers.
Byrne, L.B. 2022. The essence of soil biodiversity. Conservation Letters: doi.org/10.1111/conl.12900
Byrne, L.B., K. Szlavecz. Multidimensionality of Biodiversity in Urban Social-Ecological Soil Systems. M. Aronson and C, Nilon, eds. Routledge Handbook of Urban Biodiversity. Forthcoming.
Winiwarter, V., W.E.H. Blum. 2006. Souls and soils: a survey of worldviews. Pp. 107-122 in B. Warkentin, ed. Footprints in the Soil. People and Ideas in Soil History. Elsevier: Amsterdam.