Summit County Citizens Voice

The General Sherman giant sequoia, considered to be the world's largest living entity.

National Park Service eyes improved hydrology and better visitor access in plan for Mariposa Grove

By Summit Voice

SUMMIT COUNTY — A grove of giant sequoias that’s been growing for 3,000 years in Yosemite National Park may soon be even more peaceful. The National Park Service wants to restore natural streams in the area, remove man-made structures, relocate parking and roads and preserve the soil and vegetation around the ancient giants by re-routing trails in the Mariposa Grove.

For starters, the agency has launched a public scoping period on the plan, which is designed to try and identify broad-brush issues. The scoping started Aug. 31 and runs through Oct. 15. Get all the details on the project on this Yosemite National Park website.

The Mariposa Grove is the largest of the three giant sequoia groves in Yosemite National Park and was part of the original Yosemite Grant signed by President Abraham Lincoln in 1864 (the rest of the grant included Yosemite Valley). It was the first time in the country’s history that a natural area was set aside for the benefit of future generations.

The giant sequoias are considered to be the largest living thing on the planet. Some are up to 35 feet in diameter and up to 300 feet in height. There are approximately 500 mature sequoia trees in the grove. They are found only on the western slope of the Sierra Nevada in California, growing in a belt only about 15 miles mid and 260 miles long. In all, the groves cover about 35,000 acres. A fact sheet on the Mariposa Grove is online here.

Giant sequoias have been successfully transplanted to other areas and grow rapidly in places like England and the Pacific Northwest, but the park service is trying to preserve the endemic sequoia ecosystems on its land. The trees are listed as vulnerable on the IUCN red list of endangered species.

The Sierra snowpack provides moisture to the trees as it slowly melts during the spring. Fire also plays an important role in the life of a sequoia. It provides sunny gaps in the forest, burns heavy forest litter, and provides nutrients to soils, all of which, encourage germination for the tiny seeds. Sequoias have a relatively shallow but extensive root system, reaching to over a hundred feet in all directions from their base. These roots capture the groundwater which allows the trees to survive the long, hot summers of Yosemite. A healthy root structure is essential to ensure their longevity.

The trees reproduce with the help of two animals: A longhorn beetle species that mine the cones, drying them and enabling the seeds to fall. Douglas squirrels eat the green scales of the cone, allowing the seeds to scatter. And low-intensity ground fires dry the cones and allow large quantities of seeds to scatter across small areas. Such seed releases after fires also coincide with soil conditions favorable to germination and growth. Learn more about sequoia ecology at this U.S. Forest Service website.

The park service also wants to enhance the visitor experience at the same time by reducing conflicts between vehicles and pedestrians and improving access. During scoping, the agency wants to know what it means to “restore” the grove, and what type of improvements the public would like to see.

Giant sequoias growing in Yosemite National Park.

Filed under: biodiversity, Environment, national parks, public lands, Summit County news Tagged: | biodiversity, Environment, giant sequoias, Mariposa grove restoration, National Park Service, Travel and Tourism, United States, Yosemite National Park