Long-term Environmental ChangeGeography 430/530: Winter
2008 Instructor: Prof. Dan Gavin, dgavin@uoregon.edu, 110 Condon Hall, 6-5787, office hours 1:30-3:30pm Tues. Course overview: Climate and the pattern of life on Earth has changed continuously for millions of years resulting in the landscapes we know today. These records of past environmental changes have been assembled from a variety of different paleoenivronmental indicators. This course focuses on the methods used for paleoenvironmental reconstruction, how Earth's climate has varied over a range of different timescales, how the biota, especially vegetation, has varied in concert with climate, and the theories that have emerged to explain those variations. Emphasis will be placed on data synthesis and use of models to help understand the mechanisms underlying change in natural systems. The field trip will occur towards the end of the course so you can apply in the field the material that we covered in class, and due to the greater probability of warmer and drier weather. Prerequisites: Geog. 321 (Climatology); Geog. 322 (Geomorphology) or 323 (Biogeography). Readings: The good news: there are no books to purchase in the bookstore. All readings are either freely available online, are posted on the Blackboard website in PDF format, or are on reserve in the Science Library. The bad news: to make the best use of the reading, you will need to print up all the files using a decent-quality laser printer. One book that may be handy to own is Bradley's Paleoclimatology. This is on reserve in the Science Library, but can also be purchased from Amazon for about $60 on the 'new and used' list. Format and grading: Lectures, a mid-term and final exam, and an annotated bibliography focusing on a particular method, theme, region, or timescale involved in environmental change research. The exams will be given with open notebook. Both exams and the annotated bibliography must be completed to receive a passing grade. Final grade will be computed as: Exam 1: 25%, Exam 2: 30%; Bibliography: 35%; Class participation/attendance: 10%. There will be two sets of questions posted on Blackboard for feedback regarding the readings, and for answering longer questions about the readings. Academic dishonesty policies will be enforced. (see: http://studentlife.uoregon.edu/judicial/conduct/sai.htm). Course web page: http://geography.uoregon.edu/gavin/courses/Geog430/ |
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Instructions for creating the annotated bibliography An annotated bibliography (as used here) consists of a list of interrelated publications (usually journal articles) that address a particular theme, with short (3-5 sentence) annotations that describe a) what the article is about, b) its relationship to other publications on the same theme, and c) any other feature of the publication that would be worth mentioning. Aim to describe about five publications (but this will entail looking at many more). Example Here’s part of an annotated bibliography that focuses on recent developments on the changing biogeography of forest tree species to climate change following deglaciation: Title: Post-glacial forest biogeography in North America
This paper addresses
the
'equilibrium' between climate and forest composition using infomation
contained only in the pollen record. Their approach was to
use
information in one set of species (taxa) to predict the abundance of
another set of taxa. They suggest that there has been no
major
disequilibria lasting more than 1000 years.
Clark reintroduces
the paradox of
rapid plant migration: the fossil record suggests much faster migration
than seems possible based on seed dispersal distances. Clark
suggests that, statistically, one only needs to introduce the
possibility of very-long-distance dispersal to account for these
differences.
This paper addresses
once again
the issue of the vegetation-climate equilibrium, but their approach was
to use newly available reconstructions of past climate using
geochemical or other types of indicators of past climate that are
independent of the vegetation record, and compare these indicators to
the pollen record. They note that each of the major
vegetation
transitions is marked by some kind of paleoclimate indicator,
suggesting that climatic explanations are available for all of the
post-glacial vegetation changes that have occurred in New England.
McLachlan uses yet
another new
tool in the paleoecologist's tool box: phylogeography. DNA
indicators can reveal the relative isolation among populations, or in
other words, how long populations have been genetically isolalted from
one another. McLachlan showed that northern populations of
trees
have been isolated for periods of time longer than pollen records
indicate, suggesting very long periods of isolation and northern
refugia during the glacial maximum. This suggests tree
populations may not have had to migrate long distances during climate
change.
Etc...
Discussion These studies show the evolution of thought regarding how plant populations responded to the large climatic changes of the past 14,000 years. Concepts have changed following introduction of new and more sophisted methods: from statistical functions, to paleoclimatology, to phylogeography. The trajectory of concepts is that from large ecological effects (post-glacial migration lags) to close climatic control of populations, and finally to the importance of small refugial populations. Information sources Journals: The main journals that cover long-term environmental change or Quaternary environment topics include Science, Nature, and the following more specialized journals: Quaternary Research; Quaternary Science Reviews; Palaeogeography, Paleoclimatology, Palaeoecology; Global and Planetary Change; Paleoceanography; Journal of Quaternary Sciences; Journal of Paleolimnology; The Holocene; Geophysical Research Letters; and Journal of Geophysical Research. Indexes: The principal indexes for searching for information on the topics addressed in this course is the ISI Web of Science. This is freely available from computers on the University network. Another resource is GeoBase (check under Geography in the Databases and Indexes section). For major papers, you will be able to download the paper directly using the 'FindText' link on the search results. Book chapters or entire books are occassionally important references in this field, and these will not be referenced using the above indices, but looking at the 'references cited' of a recent important paper may lead you to such books. Last update: 1/06/2007 Department of Geography, University of Oregon, Eugene OR, 97403-1251 Course web pages originally developed by Pat Bartlein. Contact: dgavin@uoregon.edu |
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