Yosemite Natural History

Key Features and Descriptions

Largest tree in the world, up to 300’ in height, brown shreddy type bark, small cones with up to 230 seeds. Needs fire to clear ground for seedlings to sprout. Squirrels and beetles eat the seeds. Roots are embedded in a permanent stream system.

Habitat is western slope of Sierra Nevada range from Calaveras south to Sequoia National Park. One grove in far northern CA.

Sugar pine is a white pine with five needles 2’’ to 4’’ in length. The tree can grow up to 200’ in height. It has the largest cone of all the pines, up to 20” in length.

Photo from internet

The range of the sugar pine is western Oregon south through California's Sierra Nevada to southern California to western Nevada. This tree is logged in our area for many uses including housing construction.

Several times during our hike to North Dome we saw gossamer threads from spiderlings floating through the air. Young spiders will shoot out from their abdomen a silk -like thread that immediately turns into a kite shape. This kite shape gives the name to the term mechanical kiting.

Yosemite sky showing gossamer like threads floating through the air. Any reference to an extremely thin thread is called a gossamer, relating to this phenomenon. Photo courtesy of Dan Webster.

Bracken fern is a deciduous fern that grows all over the world in a variety of

habitats. It is found all over North America and Europe, parts of South

America, and Asia. It can be found in swamps, piney woods or hardwood

forest. It prefers partial shade as found here under a large Jeffrey pine.

Rhizomes send out fiddleheads each spring. Fronds grow from 1’ to 3’ and

sometimes larger. The fronds are triangular in shape.

Also known as Shinleaf. Native to California, but found outside of California as well, wintergreen can grow in any elevation up to 10,000’. It grows in shaded areas of yellow pine, red fir, lodgepole, and

redwood forests. This specimen was found in the red fir forest on the trail to North Dome. Interesting fact: There are no known specimen records in the counties of the Greater San Joaquin Valley.

This specimen was found on the Porcupine Creek trail to North Dome. Mousetails, a member of the rose family, thrive in the high Sierra

Nevada on rocky slopes and cliffs. This perennial herb has erect stems and cylindrical leaves, 2 cm-5 cm in length, whitish to silvery in color. In

spring the plant has small yellow flowers.

A very large evergreen fern that needs a year round supply of water to be happy. You will find this fern on permanent streams, creeks, and ponds. Prefers shady areas.

Fronds are large and can be up to 6’ long. This specimen was found under the canopy of bigleaf maples near a permanent stream at Hetch Hetchy Reservoir.

A polysporic shelf fungus, it grows in woody or leathery brackets, or grouping. The sulfur (yellow to orange) fruit is called a conk. It provides habitat for spiders and small organisms. Common on red fir trees, it will eventually weaken, and could kill, a tree.

Photo courtesy of Candice Mills.

I believe this to be white-leaf manzanita. It was found in the dry chaparral zone near Hetch Hetchy reservoir. The bark is reddish in color that shreds or peels in late summer. The leaves are rounded with smooth edges. The leaves are soft and fuzzy to reflect light.

Up to 12’. Phototropic.

A medicinal plant that is native to southwestern United States, it grows extensively in the Sierra Nevada mountains. Most of the US supply comes from our area. Early Spanish priests (settlers) called it a “Holy Weed” for its ability to cure many things including coughs, colds, TB, and stings from plants. Applied

as a balm it can relieve itching from a variety of sources. Isn’t it interesting that nature has provided a remedy growing in the very area where you have

acquired what ails you?

Bottom layer leaves are pointy to discourage herbivores from eating it, thus perpetuating the species. Upper leaves are smoother (picture of same plant on right)

This oak has intermingling limbs that can grow to massive girth. This specimen was a small example by Hetch Hetchy Reservoir.

Photo by Dan Webster

There are several types of bees that are black in the midsection with bombus californicus being one of them. The range of this type of bumble bee is San Francisco Bay area and throughout central California. They pollinate about 25% of the plants in California.

Picture from internet.

The Bigleaf maple is a western hardwood that has leaves 16”-24” that provide much shade. For this reason it is widely used in parks across its range from

western Canada south to California. Elevations range approximately 4000’ and lower. Prefers moist soils. Deciduous specimen found streamside at Hetch

Hetchy Reservoir.

This rock supports several species of lichen. Lichen is an organism that occurs when there is a symbiotic relationship between algae and fungus. Each of the types of lichen grows at different rates

depending on moisture and nutrients. A patch as small as a 50 cent piece could take thousands of years to grow.

This bi-ped species, with reasoning, language, and advanced tool-making abilities, has been known to inhabit the Yosemite Valley for the last 8,000 to

10, 000 years. Since early times native inhabitants have used the abundant resources available in the area to maintain a healthy and prosperous lifestyle.

Inhabitants today continue to admire, study, and preserve said resources.

The pictures in this PowerPoint were taken by Liz Miller during

the fall 2010 Biology 39 course. Several pictures were taken by

fellow classmates and duly credited. In addition there were

a few downloaded from the internet.

Sources for the material for this PowerPoint were from:•Our class fieldtrip•Textbook by John Muir Laws•A collection of Audubon Society “First Field Guides”•The internet

•First Wikipedia and then numerous links connected to Wikipedia