October 2012 Archives

In today's class, we'll start out final exercise, which will introduce you to an industry-standard software tool used to extract environmental signals from tree-ring data.

To get ready for our exercise, first download a copy of the program 'ARTSTAN' from the software page at the Lamont-Doherty Tree-Ring Program.

Second
, you should also download a copy of the Dendrochronological Program Library (DPL), which we may need for our work on Thursday.

For Mac users running OX X Lion or later, download the most recent version of ARSTAN and the DPL from the Lamont Lab's FTP site:
http://www.ldeo.columbia.edu/res/fac/trl/public/ftp/Public/

Third, download a copy of the ARSTAN manual (arstan_description.pdf).

Overview In this exercise, you'll use Google Earth to examine the global network of tree-ring data. We'll review the geographic distribution of tree-ring records and discuss why tree-ring data are common in some regions and rare in others (or completely absent). This assignment will help you understand why there are geographic biases in the application of tree-ring research and identify frontier regions for future research.

Useful resources Google Earth is available as a free download at http://www.google.com/earth/ index.html. The International Tree-Ring Data Bank is maintained by the NOAA Paleoclimatology Program and the World Data Center for Paleoclimatology at http://www.ncdc.noaa.gov/paleo/ treering.html.

Instructions for exercise: PDF

Readings for next week

| No Comments

I need to tweak the schedule for lectures a little bit to make up for the time we lost 2 weeks ago. On Tuesday (October 23), we'll discuss the history of dendrochronology, so in preparation, I'd like you to review two papers from our reading list:

Shulman (1954), Longevity under adversity in conifers. Science 119, 396-399.
Pederson (2010), External characteristics of old trees in the Eastern Deciduous Forest. Natural Areas Journal 30, 396-407.

As luck would have it, Aeon Magazine just published a great story about the ancient bristlecone pines and their role in the development of dendrchronology. It's a really interesting read, so you should check that out too.

I won't forget the first time I saw one of these erect tree-corpses, leering at me like a scarecrow beside the snow-covered road. The tree's exposed wood had aged into rich tones of gold and copper, and it seemed to leap out of the rock like a petrified flame.

Overview In this exercise, you learn how to use an industry-standard software application to confirm visual cross-dating through statistical measures of similarity or dissimilarity. We'll use the program COFECHA to assess the quality of cross-dating in one set of tree-ring width measurements and to identify potential dating errors in another set.

Instructions for exercise [PDF]

Ring-width measurements for Cat Mesa, New Mexico: [RWL]

Ring-width measurements for another ring-width record from NM: [RWL]

The set of 'problematic' ring-width measurements: [RWL]

Due Please submit a written (typed) response to both sets of questions from Part One and Part 2 at the beginning of class on Thursday, October 11. We'll discuss your findings in class on October 18 ('Sampling strategies').

About this Archive

This page is an archive of entries from October 2012 listed from newest to oldest.

September 2012 is the previous archive.

November 2012 is the next archive.

Find recent content on the main index or look in the archives to find all content.