High Elevation Jeffrey Pine in the Southern Sierra Nevada

The Northern California Botanists hosted their 13th Annual Botanical Symposium on January 13-14, 2025, at the California State University, Chico. The event brought together renowned botanists, researchers, and plant enthusiasts to delve into the latest discoveries and innovations in the field.

One of the highlights was a captivating presentation by Hugh Safford, a researcher at UC Davis, during Session 5: Lightning Talks. Safford shared his novel observations of high elevation Jeffrey pines in the southern Sierra Nevada.

While hiking the High Sierra Trail with his wife in 2024, Safford made a remarkable discovery: a miniature Jeffrey pine forest thriving at extreme elevations on Mount Kaweah, far beyond the previously documented range. Traditionally not considered a subalpine species, Jeffrey pines were thought to have an upper elevation limit of around somewhere between 10,000 or 11,000 feet. However, Safford found healthy seedlings thriving at an astonishing 12,658 feet—making them not only the highest recorded Jeffrey pines but also the highest trees of any species in California.

Key insights from his expedition include:

• The oldest trees observed were just 25 years old, with no reproductive adults in the vicinity.
• The largest trees exhibited dead upper branches, indicating significant environmental stress.
• Jeffrey pine seeds are notably heavier than foxtail pine seeds, raising intriguing questions about how they managed to reach such high altitudes.
• Clark's Nutcracker birds may be responsible for dispersing the seeds, combined with the effects of climate change, which could be enabling trees to grow at higher elevations.

What started as a casual hike quickly turned into a scientific expedition, and Safford plans to continue investigating these high-altitude phenomena in the years ahead.