Rare, Endemic Plants of the Pine Hill Preserve

 

What is a rare, native plant?

Native plants refer to the thousands of plant species that have been growing in North America since before human habitation. Rare means that the particular plant species is found in low numbers. This could mean that the plant species is common in very few locations, grows at many locations in small numbers, or, if it is very rare, exists in a few locations and in low numbers.

Plants may naturally be found in low numbers or may become rare due to human actions such as pollution, development, degradation of habitat or other activities.

 

Why are there eight rare native plants in western El Dorado County?

Significant biological diversity of plants exists in western El Dorado County just east of Sacramento, California and experts agree that unique geology, including the elevation and special soils, has a strong influence on this diversity. Other possible influences such as the role of pollinators or other mechanisms of dispersion remain a mystery.

Very distinct Rescue Series soils have been formed from the weathering of gabbro rock. Gabbro is a type of rock that is created when magma cools slowly, deep in the earth’s crust. When the rock is exposed, a rocky reddish soil high in magnesium and iron is slowly produced. The gabbro-soils, derived from rocks formed 175 million years ago, cover approximately 25,700 acres in the Pine Hill area.

Unique combinations of soils and climate often result in plants specifically adapting over time to particular places. In some cases, these plant types become constrained to the particular areas and are called endemic species–they grow in just one area in the world. Many of California’s endemic species are also rare, including species at the Pine Hill Preserve. The following plant species grow in low numbers in the Pine Hill area and nowhere else in the world!

• Pine Hill ceanothus -- Ceanothus roderickii
• Pine Hill flannelbush -- Fremontodendron decumbens
• El Dorado bedstraw -- Galium californicum ssp. sierrae
• El Dorado mule ears -- Wyethia reticulata
• Stebbins' morning glory -- Calystegia stebbinsii (There has been some observations of this species in the Grass Valley area)

Seven hundred and forty (740) different plant species have been recorded in the Pine Hill area. This means about 10% of the plant species known in California are represented within this tiny fraction of the state. (Note that the 740 species total includes non-native species.)

 

Why is it important to protect native plants?

Wild plants and animals have evolved together; hummingbirds, deer, frogs, butterflies and all native animals depend on native plants for food, shelter and survival. Native plants are both useful and beautiful.

Plants play many key roles in nature. For instance, they prevent erosion, help to maintain clean water, and limit carbon dioxide emissions. Additionally, biological diversity helps keep ecosystems functional.

Rare plants can also provide important insight into evolutionary processes and human needs by providing new compounds useful in medicines and agriculture. In particular, because the rare plants in the Pine Hill Preserve thrive on inhospitable soils, they may provide valuable insights about rehabilitating degraded areas or using marginal lands.

Concern about the rare species led to five of the native rare plant species being listed as either threatened or endangered under the Federal Endangered Species Act in 1996. The state of California has also listed one of the plants as endangered and four as rare.

 

Media - Pine Hill Preserve: New Preserves, New Fire, and New Research

Presented on by Debra Ayres on Tuesday, January 26, 2021 to the CNPS El Dorado Chapter

Debra Ayres, PhD, is a retired project scientist at UC Davis. She has degrees in botany and plant ecology. She is vice president of the CNPS El Dorado Chapter.

NOTE: There was some glitching in the presentation due to a snowstorm.