Climate Change Among the Bristlecones


Virgin Pines Press surveyed experts at the cultural epicenter of climate change — California — asking government resource managers to cite the effects of the phenomenon on their lands, under what circumstances they detected it, and where it is most noticeable to casual visitors.


We present our findings in intermittent posts.


Climate change meets stiff resistance in the Bristlecone Pine ( Pinus longaeva ) of the Inyo National Forest of southeastern California, in the Eastern Sierra region of the state.They were engineered at 11,000 feet to hold their ground amidst relentless sun and wind.  They also grow atop infertile dolomitic soil that defeats competing tree species. Their 3,000-year-old trunks have outlived numerous cycles of change.


We asked Debra Schweizer, Public Affairs Officer for Inyo, if staff had documented climate change among the storied trees. She prompted both interest and concern with her ” Yes, we have.”


She cited a disturbing trend among young bristlecone pines involving their production of resin.  They display lower levels of the sticky substance, which guards the trees by trapping insect prey.  Resin is the means by which the species copes with intense dryness, allowing it to achieve longevity.   The altered level reflects altered climate, portending shorter tree lifespans.


Downslope, an introduced fungus, whitebark pine blister rust, worries Schweizer, since the bristlecone pine bears an ecological relation to whitebark pine.  Staff have not witnessed an incursion yet, but “we are watching, ” she said.


Matthew Salzer, Research Associate at the Arizona Tree Ring Lab and co-author of a paper on bristlecone pine ecology published in the Proceedings of the National Academy of Sciences, finds the signature of climate change at the high border zone known as tree line.  There, bristlecones exhibit a burst of growth, expressed through an increase in tree ring width unprecedented in 3,500 years.   The paper’s research eliminates possible causes one by one and arrives at a correlation with higher temperatures symptomatic of climate change.  The end result would be an upward movement of tree line.


Hikers see the most obvious evidence.  Along the North Fork of Big Pine Creek, near the Ancient Bristlecone Forest visitor center, they view the Palisade Glaciers of the Sierra.  Actually,  they view melted glaciers, miniatures when indexed against historic photos.

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