Flipping Soil Biogeochemical Cycles Disclaimer PPT not pedagogically
'Flipping' Soil Biogeochemical Cycles Disclaimer – PPT not pedagogically sound (too much text!!)
Simple, general activity for complex topic Timing: mid to late semester, background in soil C and N covered; applications of biogeochemistry in Env. Sci. or other disciplines still ahead Emphasizes: • conceptual model-building • process/systems approach • interaction of biosphere, lithosphere, hydrosphere, atmosphere, and anthrosphere • group work & public speaking
There are many ways to illustrate one set of concepts.
One version of the Carbon Cycle Units in Petagrams (1015 g); Volcanic CO 2 sources not included here
C cycling in an agroecosystem Brady & Weil 2007
One version of the N cycle Brady & Weil 2007
This one is simpler for compounds, steps
Models must hold up under questioning!! Different angles: • • • Soil organisms Energy transfers Hydrological processes p. H, climate controls Mineralogy Geochronology
So: The activity What are we doing? As you were forewarned, your group today is charged with teaching the rest of the class about the biogeochemical cycle of one key soil element (e. g. , either C, N, S, P, Ca, or Fe). Your lesson should include (1) an organized, 5 -8 minute oral presentation, (2) a central graphic (model!) illustrating the basics of your element’s soil-biogeochemical cycle, and a list of discussion questions with which to engage your colleagues on the other teams. (1) Get them started with a basic understanding (w/ friendly amendments in class) (2) Ask follow-up questions that illustrate feedbacks, thresholds, environmental implications (3) Reinforce chemical knowledge (as time permits)
A few Guiding Questions… (1) What FORMS (e. g. , N 2, NH 4+, NO 3 -) of the element are involved? (2) What are the biogeochemical SOURCES of this element to the soil? Name specific minerals, rock types, or provide other details as relevant. (3) What are the major biogeochemical STEPS/PROCESSES in the elements soil biogeochemical cycle? To address this, either: (a) (“a” for acceptable) Use the appropriate figure from Brady & Weil, 2007 (I’ll have a PPT of this handy) to walk the class through the process, or, (b) (“b” for better) Create a simplified sketch that illustrates only the most important steps and processes. (4) What are the bigger picture implications of the magnitude or rate of this nutrient’s cycle for soils and landscapes? (a) What problems, if any are associated with excess supply? (b) What problems, if any are associated with deficiency?
The most basic result!! Shared via course web platform Fair game for exam questions!
A more modern approach is easy, too. • Prezi (free!) http: //prezi. com/ • Mindomo ($) http: //www. mindomo. com/ • Others? ?
A few questions for you: • Best ways to 'flip' a lecture: Reading Reflections? Videos of lecture the night before? • Best ways to 'slice' biogeochemical concepts? • What level of detail of understanding is reasonable to expect? • What means of application and learning evaluation are most appropriate?
- Slides: 13