ENVS 291M: Advanced Readings
in Biogeochemistry: Nutrient Cycling on Land
Instructor:
Weixin Cheng (phone: 9-5317, email: wxcheng@ucsc.edu)
Location:
NS2 431
Time:
9:30-11:30 am Wednesday, and TBA
This
course consists of three parts: fundamental transformation and cycling of main
nutrient elements (C, N, P, S, etc.) on land, research issues and questions in
the field of terrestrial biogeochemistry, and some key methods. Class activities include: (1) presentation of
summary statements based on reading assignments; (2) discussion of theories,
concepts, methodologies, and applications; (3) computer simulation and modeling
of elemental cycles using STELLA; and (4) integration of scientific information
by writing a review paper.
Assignment:
Each
participant is given an opportunity to choose a topic for a research review
paper). The project has to focus on a particular area of biogeochemistry. An outline of the proposed project is due by
the third lecture. Feedback from the
instructor on the outline will be given back to each participant the following
week. The anticipated length of the paper is 20-30 pages (double space, 12
point font, 1 inch margins) excluding figures and tables. Each participant will be given a time period
to present his or her project towards the end of this quarter. Course evaluation will be given based on the
quality of the paper and the presentation, and participation in the discussion
during all lecture periods.
Outline
Lecture 1:
Introduction: The biosphere concept, biogeochemical cycles, and you
review
paper
Readings:
Smil Vaclav. 2002. The Earth's Biosphere. Chapter 1: Evolution of the idea
Readings
for Lecture 2, 3,4, &5:
Exercise-1:
Build
a Stella model using the information given in Figure 11.1 of Schlesinger's
book, then estimate turnover time for the four C pools (atmosphere, plant
biomass, soil, and ocean) using current rates of fluxes. Run the model for 200 years using the time
step of one year, and see what happens to the sizes of all four pools. Do sensitivity analysis on changes of
anthropogenic CO2 emission rate, soil respiration rate, and ocean uptake
rate. Make GPP of terrestrial
ecosystems as a function of atmospheric CO2 concentration, soil respiration as
a function of soil C pool, ocean uptake as a function of atmospheric CO2
concentration, then run the model for 200 years, what do you see? If we have to "manage" the
biosphere for the purpose of reducing the atmospheric CO2 concentration, what
kinds of constraints do we have to think about? Can you set a priority list of
research areas?
Readings:
Exercise-2:
Based
on your own understanding, build a model for C and N on a piece of land
(forest, grassland or cropland). This model needs to include outside inputs,
losses from the system, internal cycling among major pools (i.e., plants, soil,
etc.). Then simulate the effect of
disturbances (e. i., fertilization, N-deposition, fire, etc.) on the modeled
pools and fluxes.
Readings:
Lecture
16: Integration and Synthesis
Lecture
17-20: Student’s project and discussion