
General Methadology for Instructors and TAs
Exercise 1: The Terrestrial Biomes: Identification of Major Controls over Structure and Distribution
Module 1: Introduction to Global Biomes
Background Lecture
- Introduction to course objectives, logistics
- Introduction to major ecological divisions
- Global biomes:
- Definition
- Distribution of terrestrial and aquatic biomes. Discuss and collectively produce a global map of biomes.
- Factors that control distribution and structure.
See Global Biomes Mod 1 lecture outline.doc for an outline for this material Need to select from this material for it to be a more reasonable length. And see EPOB lecture web.ppt (PowerPoint presentation) for images that might be useful. Downloadable from the web at http://www.cgd.ucar.edu/edas/tim/epob.htm
- Review the scientific method and hypothesis testing.
Activities in the experiment
- This is a digital lab exercise.
- Activity questions, task, and steps are outlined above.
- Prep Discussion: Ample time should be set aside to introduce the climate diagram methodology
- Students are encouraged to confer with their lab mates in selecting stations and to discuss the key features of the major biomes.
- Not all biomes need to be covered by the class as a whole.
- This activity is the most directed of the courses exercises, in that, students can seek guidance from instructors in designing their biome-specific hypotheses. In addition to the subject matter, students should be getting a first hand experience of how to generate and evaluate hypotheses.
- No statistics for this exercise.
Hypotheses to test
All climatic features are discernable in the climate diagrams.
- Primary divisions among biomes in higher latitudes are related to thermal controls. In other words, thermal regime directly controls the distribution of Arctic tundra, boreal woodlands, and forests and evergreen vs. deciduous boreal conifer forests (Larix in Siberia).
- Among temperate, subtropical, and tropical biomes, divisions are determined by thermal and moisture limits. For example, thermal gradients in eastern US forests from south to north are reflected in the changing structure of these forests.
- Thermal and moisture limits have a strong seasonal component. This is evident in most systems e.g. gradients in precipitation seasonally in tropical forests and in the western US, and in temperature seasonally in boreal forests of Eurasia.
- Students are expected to derive and evaluate additional, more biome-specific hypotheses on climatic controls over structure, with guidance from instructors and references.
Independent variables in the experiment
- Climatological means of monthly mean temperature and monthly precipitation
- Other temperature and precipitation variables are often included in Walter diagrams, but these are more difficult to find in climate datasets. However, the Lieth et al. CD may have these available.
Dependent variables that they could use in their experimental design.
- Biome features. In particular, vegetation lifeforms/plant functional types
Student evaluation
- Students will be evaluated base on an oral presentation and participation in discussion,
- Evaluation will be done based on outcome and the students will receive similar/identical grades based on the results of presentation and their participation during the project
Preparation notes
- Portable?: Exercise is lab only, so not affected by inclement weather unless power outages or surges require digital lab to be shutdown. In which case, discussion of climate diagrams and vegetation structure can proceed with hardcopy materials (reference books) and graph paper(!).
- Preparation before course:
- CDs (Lieth et al and Wilson and Perlman) need to be loaded on to system and tested
- Need to post and check web pages that will act as data sources and references.
- Shared data/Web site: If climate diagrams are posted to course web site, then presumably students can look at diagrams for the three sites (as well as for other stations). As the courses will have different schedules (and given time zone differences), this information will likely not be available to all students during the exercise but may be useful in shared activities later on.
- Web resources:
Authors: T. Kittel, J. Danoff-Burg, and A. Hoylman