Tag Archives: bristlecone

Rocky Mountain High #2

Pat Frank thought that I was being a little sarcastic of the rigors of updating tree ring collections at Niwot Ridge. However, I’d like now to give what is perhaps a better example of what Mann had in mind when he explained the inability of paleoclimatologists to update tree ring collections. Just to review, here’s […]

Ring Widths and Temperature #1

A common theme to recent questions has been the relationship of ring width chronologies to temperatures, and, in particular, the relationship of bristlecone chronologies to temperature. Rob Wilson has recently weighed in on this. While it was nice of Rob to present some new material, people should not lose sight of the fact that the […]

A New Spaghetti Graph

Von Storch and Mann have both said that, in an MBH98-type reconstruction, it is impossible to allocate the impact of individual proxies. This is incorrect as we pointed out in MM05b. My posts on MBH98 Linear Algebra showed this more clearly (or at least in more detail). However, those posts only took the analysis back […]

Rob Wilson on Bristlecones

Rob Wilson sent in a post on another thread arguing that bristlecones are not as bad a proxy as I would have everyone believe. Unlike realclimate, opposing views are not censored here. In fact, I’m happy to highlight them. I’ll read Rob’s note and reply on an another occasion. I’ll only note now that, in […]

New York Times on Bristlecones

I’ve been working away at our reply to Ammann and Wahl so I’m a little behind in blogging. One of our readers drew my attention to a discussion in the New York Times involving our favorite bristlecone pines. Kammerer et al. [J. Im. Gen. 2006] report the extension of human lifespan to 969 years following […]

Upper and Lower Bristlecone Sites

A while ago, I discussed the very interesting study by Naurzbaev et al [2004] (co-author Hughes), which calculated growth curves at 34 larch sites in a meridional transect from 55 to 72 N (at a longitude of about 90-100E) and 23 larch sites along an altitudinal transect from 1120 to 2350 m around Tuva (~ […]

Graybill and Funkhouser [1993] on Bristlecones

I have recently located a copy of Graybill and Funkhouser [1993], Dendroclimatic Reconstructions during the past millennium in the southern Sierra Nevada and Owens Valley, California, which has been very hard to find. This appears to be Graybill’s last publication before he died. A detailed excerpt follows. Some key quotes: Unfortunately the chronologies from the […]

Lamarche on Treelines #2

Here is Lamarche’s diagram of altitudes at the key bristlecone sites of Sheep Mountain and Campito Mountain (as noted below, when wood erosion is allosed for, the post-MWP decline is placed after 1500.)

Lamarche [1973] on Treelines #1

Valmore Lamarche was perhaps the first person to suggest that temperature information could be extracted from bristlecone pine information and his early publications are often referenced. Lamarche et al. [1984] (with Fritts, Graybill and Rose) first postulated CO2 fertilization. As you know, I’m increasingly interested in changes in treeline elevation as a "low-frequency proxy". It […]

Bristlecone dC13

I’ve recently run across an article on changing water use efficiency in bristlecones, which pretty much put the nail in the coffin on any lingering ideas that 20th century bristlecone ring widths might be a temperature proxy. Tang et al. [1999], "The dC13 of tree rings in full-bark and strip-bark bristlecone pines in the White […]