Friends of the Dunes

Science & Nature

Further Reading

Frequently Asked Questions about Dune Ecological Restoration

Pickart, A. 2008. Restoring the Grasslands of Northern California’s Coastal Dunes. Grasslands. Published by the California Native Grasslands Association. Vol XVII, No. 1.

Pickart, A.J., and J.O. Sawyer. 1998. Ecology and Restoration of Northern California Coastal Dunes. California Native Plant Society, Sacramento, CA.

Restoring the Dunes

Dune systems depend on constant change. Invasive plants have upset the ecological balance by inhibiting sand movement, changing soil chemistry and crowding out native plants. Many invasive plants were first introduced to the dunes for the purpose of stabilizing the shifting sands in the early 1900’s.

The study of dune restoration first began at the Lanphere Dunes in the late 1970’s. Since then a lot has been learned about the practices of restoring dunes and how dunes react to the removal of invasive plants. Restoration of the dunes on the North Spit in Humboldt County focuses on hand removal of non-native, invasive plant species. With minimal disturbance to the land during restoration activities, the ecosystem is able to regenerate quickly. Native plants are able to increase in number and reclaim areas once invaded. This helps restore native biodiversity and return natural processes to the dune ecosystem.

You can learn more and get involved in restoring local dunes by participating in one of our volunteer restoration programs.

Invasive Plants

Beachgrass

European beachgrass (Ammophila arenaria)

Native to Europe, this grass was planted along the north spit in 1901 to stabilize the sand along the railroad. The Latin name Ammophila means "sand-loving" as the grass thrives on being buried. This grass spreads by deep, tough, buried stems (rhizomes) and forms dense, continuous stands.

Dune Impacts – European beachgrass traps blowing sand and does not allow it to continue through the dunes system, causing dune stabilization. Sand movement is a critical part of the dynamic dune system and over stabilization creates an unnatural condition on the dunes. The thick stands that it forms crowds out native plants.

Control – European beachgrass is removed with hands and shovels. Although this is labor intensive, it is the most effective method locally. Because this grass is constantly being buried with sand its root systems grow deep in the sand. This makes it virtually impossible to remove the entire root. Portions of root remaining after initial removal efforts will re-sprout and will require 4-8 follow-up treatments before being starved of nutrients and die. Beachgrass is piled up and left to dry before being burned.

Iceplant

Iceplant (Carpobrotus chilensis and Carpobrotus edulis)

Iceplant is native to South Africa. It is believed that it was introduced to local dunes as early as the 1500’s in sand used as ship’s ballasts. The origin of Carpobrotus chilensis is not clearly understood, and some biologists believe it is native to California. This species is far less invasive than C. edulis. However, when C. chilensis hybridizes with C. edulis, it takes on more aggressive traits and should be controlled.

Dune Impacts - Iceplant is a succulent which stores water in swollen leave or stems enabling it to survive after being uprooted. It grows low to the ground and blankets the dunes, crowding out native plants, and stabilizing sand.

Control - Iceplant is easily controlled with manual removal. Large clones can be rolled up like a carpet with the roots being cut with shovels underneath as it is rolled. Small patches are piled up and left to dry. After a few months piles are revisited and any pieces of the plant that are touching the ground and growing are removed and placed on the top of the pile until all of the pile is dead and dry.

Lipine

Yellow Bush Lupine (Lupinus arboreus)

Yellow bush lupine is native to central California, but this species is not native to Humboldt County. There are two other species of lupine that are considered to be native here, but are smaller and less commonly seen on the dunes. Yellow bush lupine was introduced to the North Spit in the early 1900’s when the railroad was being used to transport rock to construct the north jetty. Five women were hired by the Army Corps of Engineers to plant the lupine seeds along the railroad to prevent unwanted sand burial. The seeds were obtained by the Presidio in San Francisco.

Dune Impacts – Yellow bush lupine is a large shrub that creates a new microclimate by providing shade and moisture to surround plants. The roots have nodules which contain nitrogen-fixing bacteria that increase nutrients and organic matter in the sand, creating a condition where other weedy plants can become established.

Control – Small yellow bush lupines are removed by physically pulling up the entire plant, including the deep tap root. Larger bushes are removed using an axe to chop the plant off at the base. Shrubs are then piled, dried and burned. Lupines have long lasting seed banks, so removal efforts must be continuous as new plants will emerge from seeds that have previously been dispersed.

Stewarding Our Coastal Dunes

Carol Vander Meer / My Word, 05/21/2013

You may know Friends of the Dunes for our Annual Sand Sculpture Festival, or our school programs that have introduced thousands of Humboldt County students to the coastal dunes, or maybe you know us as the group that opened up the Humboldt Coastal Nature Center. We are all of those things and more, including being a group working to involve the community in restoring the natural diversity of coastal environments by removing invasive, non-native plants like European beachgrass.

Friends of the Dunes has been involving the community in coastal conservation for over 30 years. We are an active member of the Dunes Cooperative that facilitates coordinated ecosystem management of coastal dune environments through collaboration of local land managers. Our staff and Board of Directors have expertise in natural resource management, geology/geomorphology, wildlife biology, plant ecology, and education.

There have been some misconceptions circulated lately about coastal restoration activities and their impacts. We would like to offer some insight about the process of restoration, how it helps restore natural diversity and its relationship to coastal processes. Friends of the Dunes works with experts in coastal land management, scientists working in coastal processes and members of the local community to support the restoration of resilient coastal ecosystems, while also accounting for the needs of neighboring communities.

The goal of dune restoration is to restore the natural diversity of plants and animals to the dunes and help return, where appropriate, the natural processes that sustain dune ecosystems. It is the varied conditions caused by a constantly shifting, changing landscape that creates the unique, diverse habitats for plants and animals that we enjoy today. Dunes are by nature moving and dynamic. In some places forests become covered with sand, while in other areas new forests develop. Open sand is often quickly colonized by early successional plants. Wetlands are formed when dune swales are carved out by the wind down to the water table, but their locations shift and change as sands move. It is an active cycle of processes that creates and sustains these shifting habitats and biological communities.

Our dunes are wide and broad with a relatively low foredune, a broad, undulating expanse of mid-dunes and much higher forested back dunes. Unlike some places along the Oregon coast, where houses are built right on the coastline, most buildings and homes along our coast are at least a quarter of a mile or more from the beach, and were built in stable, forested back dunes. This makes it possible to restore some dune processes, closer to the ocean, without threatening property and homes. In areas near communities or infrastructure, we are adapting our approaches to restoration to include plantings of native dune plants, which reduces sand movement.

We are open to dialogue about how to incorporate the best science available to ensure that the beauty and dynamic nature of the dunes is enjoyed today and for generations to come. How to adapt to ongoing climate change is one of the important questions in coastal dune management today.

Ongoing studies are underway that will help us to predict how our dunes will change as sea levels rise, and how vegetation may respond to these changes. Andrea Pickart, ecologist for Humboldt Bay National Wildlife Refuge, recently wrote in an article in our newsletter, Dunesberry:

"In some ways, coastal dunes are one of the more resilient ecosystems with respect to climate change. Located at the boundary zone between marine and terrestrial ecosystems, they are dynamic systems that have historically undergone constant, albeit gradual change in response to climate and related sea level changes. From this long history of change, we know that dunes have the capacity to migrate and equilibrate with new sea levels."

Friends of the Dunes will continue to work with scientists and coastal land managers to develop and implement the best dune management and restoration practices for our coastal areas. We will further the work of coastal conservation by sharing the beauty of our coast to students, visitors and community members through educational opportunities, restoration efforts and conservation projects. We do this because we believe that connecting people to nature is an essential part of conserving and protecting the ecosystems which sustain us.


Friends of the Dunes | PO Box 186, Arcata CA 95518 | 707-444-1397 | info@friendsofthedunes.org

Please report any problems with this web site to webmaster@friendsofthedunes.org. Thank you!