ESCI 431 Watershed Biogeochemistry
Fall 2013
3 credits
Meeting time and place: MWF 9 am, ES 418
Instructor: Peter S. Homann, ES 436, phone 650-7585, email Peter.Homann@wwu.edu
office hours: MWF 10:00-11:00 am and by appointment
Brief description: Transfer, cycling, and interaction of carbon, nutrients, and other elements
within and between terrestrial and aquatic ecosystems. Physical, chemical and biological
influences on transfers. Computer simulation modeling of processes in an ecosystem context.
Objectives: (a) to develop a nutrient budget for a watershed, using the P budget of Lake
Whatcom watershed as a focus. (b) to learn how nutrient cycling and carbon cycling are
influenced by vegetation, microbial, chemical, and physical controls. (c) to manipulate a nutrient
cycling spreadsheet simulation model that incorporates pools, processes, fluxes and controls. (d)
to summarize and present information using standard biogeochemical terminology and
approaches.
Course format: Class lectures, class discussions based on readings, quantitative homework
assignments, student presentations exams. There is no textbook. Readings will be made
available through Canvas (ESCI 431 – Files – Syllabus, ESCI 431 – Files – Readings).
Prerequisites: ESCI/BIOL 325 Ecology; and ESCI 361 Water Quality or ENVS 327 Soils.
Of possible interest: Homework, lecture notes, and information posted on Canvas (ESCI 431 –
Files – Homework, ESCI 431 – Files – Lecture Notes).
Evaluation, grading, and feedback: One mid-term and one final exam (together worth 60% of
final grade). Homework assignments, class discussions and presentation (40% of final grade).
Late HW may not receive full credit.
>96.0% A
>92.0% A-
>89.0% B+
>86.0% B
>83.0% B-
>80.0% C+
>77.0% C
>74.0% C-
>71.0% D+
>68.0% D
>65.0% D-
<65.0% F
Readings: Readings are available on Canvas or through web links indicated on the schedule
below. If a link does not work, try again on a university computer. At a web site, click on PDF
to see entire article. Read the entire article unless directed otherwise on the schedule.
Readings are to be completed prior to class. For all readings, take notes and be prepared to
discuss readings in class. In addition to other information, know where the study was conducted
and the type of system. Follow any specific instructions that are given below in the schedule.
Week 1
1. Wed Thinking differently, Biogeochem overview, Lake Whatcom overview
2. Friday Lake Whatcom P
P. Pickett and S. Hood. 2008. Lake Whatcom watershed total phosphorus and
bacteria maximum daily loads. Volume 1. Water Quality Study findings.
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Publication No. 08-03-024. Department of Ecology, State of Washington. Read
pages 13-20, 32, bottom of page 35, 36, Fig 1 on p. 99, Fig 34 on p. 132. In this
document “Full rollback scenario” means pre-development and “base scenario”
means conditions in 2003. See report under Canvas (ESCI 431 – Files – Readings)
Pool-Process-Control handout (see “ESCI 431 Fall 2013 pool process diagram.doc”
under Canvas (ESCI 431 – Files – Readings))
Temporal variation in solute concentration
Assign HW 1 Temporal variability of stream P concentration in Lake Whatcom
Watershed
Week 2
3. Monday
HW 1 due
Spatial variation in stream P conc and impervious surfaces
Assign HW 2 Spatial variation in stream P concentrations in Lake Whatcom Watershed
4. Wed
HW 2 due
Water budgets
Assign HW 3 Water Budgets of basins in Lake Whatcom Watershed
5. Friday
HW 3 due
Stream P inputs, concentrations vs. fluxes, dilution effect
Assign HW 4 Stream P inputs into Lake Whatcom
Week 3
6. Monday
HW 4 due
Groundwater P inputs
Assign HW 5 Groundwater P inputs into Lake Whatcom
7. Wednesday
HW 5 due
Atmospheric deposition
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Assign HW 6 Stream, Groundwater, and Precipitation P inputs into Lake Whatcom
8. Friday more Atmospheric Deposition
K.A. Anderson and J.A. Downing. 2006. Dry and wet atmospheric deposition of
nitrogen, phosphorus and silicon in an agricultural region. Water Air Soil Pollution
176: 351-374. Read pages 351, 352, 353. Examine phosphorus results in Tables I, V,
and VII. Note the different units in the different tables. How are those units related?
http://www.springerlink.com/content/c537103r011nr007/fulltext.pdf
Soil P, forms of P
Assign HW 7 Soil P pools
Week 4
9. Monday Soil controls on P
T. Wood et al. 1984. Phosphorus cycling in a northern hardwood forest: Biological
and chemical control. Science 223:391-393. State your conclusions about Figs 1, 2
and 3.
http://links.jstor.org.ezproxy.library.wwu.edu/sici?origin=sfx%3Asfx&sici=00368075(1984)223%3A4634%3C391%3APCIANH%3E2.0.CO%3B2-G
10. Wed Atmospheric Deposition of N
HW 6 and 7 due
11. Friday more Atmospheric Deposition of N
A.O. Langford and F.C. Fehsenfeld. 1992. Natural vegetation as a source or sink for
atmospheric ammonia: a case study. Science 255:581-583. State your conclusions
about Table 1 and Figure 2. Draw a pool-process-control diagram that represents
this article.
http://links.jstor.org.ezproxy.library.wwu.edu/sici?origin=sfx%3Asfx&sici=00368075(1992)255%3A5044%3C581%3ANVAASO%3E2.0.CO%3B2-E
Nitrogen fixation
Week 5
12. Monday more Nitrogen fixation
B.A. Hungate et al. 2004. CO2 elicits long-term decline in nitrogen fixation.
Science 304:1291. State your conclusions about Figure 1. Draw a pool-processcontrol diagram that represents this article.
http://links.jstor.org.ezproxy.library.wwu.edu/sici?origin=sfx%3Asfx&sici=00368075(2004)304%3A5675%3C1291%3ACELDIN%3E2.0.CO%3B2-L
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13. Wed more Nitrogen fixation
J.E. Compton et al. 2003. Nitrogen export from forested watersheds in the Oregon
Coast Range: The role of N2-fixing red alder. Ecosystems 6:773-785. State your
conclusions about Figures 1, 3, 4, 5. Draw a pool-process-control diagram that
represents this article.
http://www.springerlink.com.ezproxy.library.wwu.edu/content/0w7e0ce28d7clcxk/
Review for exam
14. Friday Oct 25 exam
Week 6
15. Monday Veg influences
P.M. Vitousek and W.A. Reiners 1975. Ecosystem succession and nutrient retention:
A hypothesis. Bioscience 25(6):376-386. State your conclusions about Figures 1
and 2, and Table 1. Draw a pool-process-control diagram that represents this
article.
http://links.jstor.org.ezproxy.library.wwu.edu/sici?origin=sfx%3Asfx&sici=00063568(1975)25%3A6%3C376%3AESANRH%3E2.0.CO%3B2-Q
Assign HW 8 N fixation by mass balance
Decomposition
16. Wed more Decomposition
J.M. Melillo et al. 1982. Nitrogen and lignin control of hardwood leaf litter
decomposition dynamics. Ecology 63:621-626. State your conclusions about
Figures 1,2,3.
Note: Melillo et al. discuss a “k” constant. k is called the rate constant or the
decomposition constant. It is from the exponential decay equation
Remaining mass (%) = 100% * ekt
Where t is time in years, and k has negative values. Thus, the more negative the
value of k is, the less remaining mass there is.
http://links.jstor.org.ezproxy.library.wwu.edu/sici?origin=sfx%3Asfx&sici=00129658(1982)63%3A3%3C621%3ANALCOH%3E2.0.CO%3B2-Z
17. Friday Soil organic matter processes
HW 8 due
Week 7
18. Monday riparian model
no reading, but…
What is the derivative of ekt ?
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assign HW 9 Riparian Model
19. Wednesday Denitrification
E.A. Davidson et al. 2000. Testing a conceptual model of soil emissions of nitrous
and nitric oxides. Bioscience 50:667-680. State your conclusions about Figures
2,3,4d,5b,6. Draw a pool-process-control diagram that represents this article.
http://links.jstor.org.ezproxy.library.wwu.edu/sici?origin=sfx%3Asfx&sici=00063568(2000)50%3A8%3C667%3ATACMOS%3E2.0.CO%3B2-3
20. Friday Cation release from mineral weathering
J.R. Gosz et al. 1983. Using strontium isotope ratios to estimate inputs to
ecosystems. Bioscience 33(1):23-30. State your conclusions about Figures 1, 2, 3.
Draw a pool-process-control diagram that represents this article.
http://links.jstor.org.ezproxy.library.wwu.edu/sici?origin=sfx%3Asfx&sici=00063568(1983)33%3A1%3C23%3AUSIRTE%3E2.0.CO%3B2-X
assign HW 10 Student presentations
Week 8
21. Monday Veterans Day. Nov 11. No class.
22. Wednesday controls on mineral weathering
E.H. Hoffland et al. 2004. The role of fungi in weathering. Frontiers in Ecology and
the Environment 2(5):258-264. State your conclusions about Figures 1,2,3,4.
http://links.jstor.org/sici?sici=15409295%28200406%292%3A5%3C258%3ATROFIW%3E2.0.CO%3B2-1
HW 9 due
23. Friday Clay structure and cation exchange
N.F. Foley. 1999. Environmental Characteristics of Clays and Clay Mineral
Deposits. USGS Information Handout.
http://pubs.usgs.gov/info/clays/
HW 10 student presentation topics due
Week 9
24. Monday more cation exchange
25. Wednesday Cation cycling
S.P. Hamburg et al. 2003. Biotic control on calcium cycling in northern hardwood
forests: acid rain and aging forests. Ecosystems 6:399-406. State your conclusions
about 1, 2a, & 3. Draw a pool-process-control diagram that represents this article.
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http://www.springerlink.com.ezproxy.library.wwu.edu/content/7bt1c95cch915480/
26. Friday Anion exchange
Week 10
27. Monday Student presentations (HW 10)
28. Wednesday Thanksgiving holiday. No class.
29. Friday Thanksgiving holiday. No class.
Week 11
30. Monday Student presentations (HW 10)
31. Wednesday Student presentations (HW 10)
32. Friday Review and course evaluations
Finals Week—Monday Dec 9 @ 10:30 am: final exam
Changes to the Syllabus, if there are any,
will be announced in class and presented on Canvas.
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