The bristlecone pines that created the shape of the Hockey Stick graph are used in nearly every millennial temperature reconstruction around today....
Of course, RealClimate shows three reconstructions from the year 1600 or earlier without bristlecones or any other tree rings, and multiple other reconstructions without the particular Yamal tree rings that Lindgren is now going on about. (Update: above sentence corrected from four reconstructions starting in 1500, my thanks to Glen in comments for spotting this.) I haven't followed the Yamal controversy that closely except to know that most people who have think it's nonsense. Maybe there's something new here, but I doubt it. (It appears to be all about the data not being available, refuted at Deltoid two months ago.)
Lindgren is pumping out the usual nonsense (by implication, not directly) that the climate consensus is based on a single piece of information, and that info is corrupt. He needs to get his head on straight before accusing other researchers of being ethically-challenged.
Lindgren earned a lot of credit by taking on his fellow conservative, the ethically-challenged John Lott. He's used up a bit of that credit now.