Restoring Yosemite’s Tuolumne Meadows: Early Gains Amid Long-Term Challenges

Researchers from Colorado State University (CSU) planted roughly 40,000 native sedge seedlings (Carex scopulorum) in Tuolumne Meadows, the high-elevation wet meadow of Yosemite National Park. The seedlings were introduced in 2016 and have been monitored for three years. Early results show modest improvements in soil organic matter, yet the meadow continues to emit more carbon than it sequesters. The study was published in the *Journal of Geophysical Research: Biogeosciences* on October 6.

The 40,000 seedlings bringing life back to Yosemite’s meadows NewsweekScientists replant Yosemite's Tuolumne Meadows in race to revive

In the mid-1800s, massive flocks of sheep grazed the Sierra Nevada high country, heavily consuming the deep-rooted sedges that once dominated Tuolumne Meadows. By the time Yosemite became a national park in 1890, the meadow was already degraded, with shallow-rooted plants replacing the original vegetation. Over the ensuing 150 years, the loss of sedge roots reduced soil moisture retention, accelerated decomposition of organic matter, and exposed more than 20 % of the meadow’s topsoil.

The 40,000 seedlings bringing life back to Yosemite’s meadows Scientists replant Yosemite's Tuolumne Meadows in race to revive

• Seedlings planted: ~40,000

Newsweek

• Survival after three years: about three-quarters remain alive

Scientists replant Yosemite's Tuolumne Meadows in race to revive

• Topsoil exposure: >20 % of the meadow’s surface is bare

Scientists replant Yosemite's Tuolumne Meadows in race to revive

• Carbon balance: net carbon loss persists; decomposition outpaces new carbon inputs from seedlings

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• Restoration timeline estimates:

Scientists replant Yosemite's Tuolumne Meadows in race to revive

• Colorado State University researchers project 25–30 years

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• Other sources cite 25–50 years (Discoverwildlife, bioengineer)

Scientists replant Yosemite's Tuolumne Meadows in race to revive

Cooper also noted that “success should also include habitat, erosion control, and water-related functions—not solely whether the meadow has already become a carbon sink.”

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She stressed the need for “long-term monitoring” to determine whether early gains translate into sustained carbon storage.

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• “Success should also include habitat, erosion control, and water-related functions—not solely whether the meadow has already become a carbon sink.” — Ultimately

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• “We feel our approach of planting the species that was and should be the dominant vegetation is the path forwards,” — David Cooper, lead author

The 40,000 seedlings bringing life back to Yosemite’s meadows

• “Many ecosystems do not naturally recover from severe disturbance, and while a place may look green, it may be severely degraded and in need of restoration,” — David Cooper, lead author

The 40,000 seedlings bringing life back to Yosemite’s meadows

The principal point of divergence among the sources concerns the projected duration required for full meadow recovery. Newsweek cites a 25–30-year horizon, whereas Discoverwildlife and bioengineer both suggest a broader 25–50-year window. No source provides a definitive timeline for when the meadow might transition from a net carbon source to a net sink, leaving a critical knowledge gap for future management planning.

Scientists replant Yosemite's Tuolumne Meadows in race to revive

Tuolumne Meadows functions as a carbon reservoir, a water-filtering landscape, and a habitat for iconic Yosemite wildlife. Continued carbon loss contributes to atmospheric CO2 concentrations, while diminished water-holding capacity threatens downstream water quality. Restoring the sedge-dominated wet meadow could, over decades, re-establish these ecosystem services, but the process demands sustained investment and monitoring.

Scientists replant Yosemite's Tuolumne Meadows in race to revive

Researchers recommend tracking plant establishment, groundwater levels, soil carbon, and greenhouse-gas exchange against unplanted control plots. Continued observation over a decade or longer is deemed essential to assess whether early improvements in soil organic matter evolve into a stable carbon sink and to guide adaptive restoration actions.

Newsweek