Nutcrackers and Nighttime Warming: Unexpected Treeline Dynamics in the High Sierra Nevada

Our friends at the Tahoe & Sierra Valley Chapter of California Native Plant Society are hosting a talk. Read Below:
Nutcrackers and nighttime warming: unexpected treeline dynamics in the High Sierra Nevada with Dr. Hugh Safford
In the summer of 2024, Hugh found an extraordinarily high-altitude population of young Jeffrey pines in the Kaweah Mountains, at elevations up to nearly 12,700 feet. This is 1000s of feet above the generally recognized range of the species, and – unbelievably – the population included the highest formally recorded individuals of any tree species in California. This find set in motion a study of the Jeffrey pine phenomenon, its extent, its drivers, and its meaning. In the summer of 2025 Hugh’s team surveyed tree populations above timberline in Yosemite and Sequoia-Kings Canyon National Parks, as well as in the Inyo National Forest and the Lake Tahoe Basin Management Unit.  They found that the Jeffrey pine phenomenon is much more widespread than previously believed, found that individuals of all of the subalpine tree species are growing at higher elevations than previously documented, and found the first trees – all whitebark pine – ever reliably recorded above 4000 meters (13,124 feet) in California. An interaction between the warming climate and bird dispersal of seeds is driving much of what they see.  Hugh will report on the findings from last summer, describe what they know about the current status of the Jeffrey pine invasion, and theorize a bit about how this invasion may fundamentally change Sierra Nevada subalpine forests.”
Dr. Hugh Safford is a research ecologist in the Department of Environmental Science and Policy at the University of California-Davis, which he joined in 2003. Safford was also Regional Ecologist for the USDA-Forest Service’s Pacific Southwest Region between 2001 and 2022.  The Safford Lab at UC-Davis is focused on applied ecological support to resource, forest, and fire management in California and worldwide.  Safford has provided technical assistance on fire, forest management, and climate change issues in the US and abroad since the 1990s.