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Frequently Asked Questions

What are "Natural Areas?"

The City of San Francisco has a diverse array of parks and open spaces, a portion of which are Natural Areas. Natural Areas are remnants of San Francisco's historic landscape. They contain rich and diverse plant and animal communities that differ dramatically from one another. These communities include oak woodlands, creeks, lakes, grasslands, dunes, scrub and rock outcrops. In many cases these nature preserves are the only places where wildlife such as the Red-tailed Hawk, Gray Fox, Great-horned Owl, and San Francisco Garter Snake still reside, reproduce and play.

How much of city lands are Natural Areas?

Of the 3,500 acres and 230 parks in San Francisco managed by the Recreation and Park Department, Natural Areas comprise approximately 500 acres in 35 parks or portions of parks. What are some examples of these nature preserves in San Francisco Most of the undeveloped portions of Twin Peaks, Lake Merced and Glen Canyon Park are natural areas. Natural Areas do not contain manicured lawns, ballfields or ornamental flowerbeds. Most of Golden Gate Park, approximately 96 percent, is not a Natural Area.

What is the Natural Areas Program?

The Natural Areas Program (NAP) is the division of the San Francisco Recreation and Park Department responsible for managing Natural Areas. The NAP began in 1997 in response to concerns raised by citizen, school and environmental groups that San Francisco's natural heritage was being lost. The NAP is a community-based habitat restoration program whose mission is to protect and preserve our natural areas and biodiversity for future generations through stewardship and citizen involvement. The City General Plan (Open Space Element, Policy 13) mandates the protection of Significant Natural Resource Areas and states that "natural resources of the site should be protected and enhanced through restrictions on use and appropriate management practices. Native plant habitats should be preserved and efforts undertaken to remove exotic plant species from these areas." So the management activities undertaken by the NAP are fulfilling a city mandate.

What is biodiversity and why is it important to preserve these sites?

The Bay Area is considered a biodiversity hotspot. Simply stated, biodiversity is the variety and variability of life. Biodiversity is important because it represents the web of life in which humans exist and upon which we depend. Usually, biodiversity is measured by the number of plant and animal species in an area. Due to the unique combination of natural forces (wind, climate, geology and geography), many different plants and animals have evolved here, some of which exist nowhere else on earth! Some of the rare or endangered species that exist in Natural Areas include the Mission blue butterfly, the San Francisco forktail damselfly and the San Francisco wallflower.

Why preserve nature in the middle of a big city?

People of all ages find refuge in these urban oases. These areas give the people of San Francisco a sense of place and distinguish it from anywhere else on earth. Preserving the historic nature of San Francisco is just as important as preserving its historic cultural legacy. Furthermore, these urban natural areas provide educational opportunities. Through the Recreation and Park Department's School Stewardship Program, urban school children have an opportunity to experience and learn about the nature that exists in their own backyard and neighborhood. The Natural Areas and School Stewardship Programs give residents an opportunity to act locally on global environmental issues.

What's so important about saving one species when the earth already has so many?

Each species of plant and animal fills a unique role in our natural world. Just as the strands of a spider web are interconnected, so too are species in an ecosystem. While a web can still function with a few missing strands, continued disruption will eventually cause collapse. In the natural world, the loss of species compromises the integrity of the ecosystem. Habitat loss, pollution, urbanization and the spread of noxious weeds are among the causes of species extinction. The integrity of San Francisco's ecosystem is dependent on Natural Areas and the life they support.

What does the NAP do in our parks?

The staff and volunteers work to preserve and restore Natural Areas by reducing the impacts of urbanization, fragmentation and habitat loss. The thousands of volunteers who work with the NAP each year, restore nature in San Francisco by removing noxious weeds, growing and replacing plants, planting food and cover plants for wildlife, controlling erosion, improving trails and educating others. In addition, the NAP staff promotes environmental awareness through free trainings, educational materials, conferences and presentations.

What portion of Recreation and Park Department resources is devoted to natural areas management?

Out of 300 Recreation and Park gardeners, nine are in the Natural Areas program. The Recreation and Park Department spends $89 million (for operations and recreation), but only $600,000 (or approximately 0.67%) is used for Natural Areas.

How will habitat restoration affect the appearance of our park?

Contrary to recent media portrayals, it is not the mission of the NAP to restore San Francisco to sand dunes. Just as the gardeners tending the lawns of a ball field are not attempting to convert our entire park system to ball fields, the NAP does not restore landscaped areas to Natural Areas. Most of the restoration activities that have been performed by NAP staff and volunteers in the last five years have gone relatively unnoticed by many park users. This will continue to be the case-the existing look and feel of your local natural area will remain largely unchanged.

Why do humans need to be involved in preserving our Natural Areas? Doesn't nature take care of itself?

Preservation of natural areas requires the participation of people. Throughout history, humans have moved plants and animals around the globe, out of the environments they evolved and into different areas. Sometimes species have been introduced intentionally, like iceplant to stabilize soils, or unintentionally like the Norwegian rat. A small proportion of theses introduced plants and animals have the capability to spread and become weeds in our natural areas. Just as humans are responsible for introducing these species, some believe we are obliged to act as stewards of our remaining natural heritage. This approach is not unique to San Francisco or to this century. The NAP, in conjunction with other land managers such as the Golden Gate National Recreation Area and the Port of San Francisco, encourages such stewardship. Also throughout time humans have managed land for our specific purposes. In San Francisco, three hundred years ago, the indigenous people, the Ohlone, intentionally set fires to maintain grasslands that supported the bulbs and other food plants upon which they relied. Some of these species such as Ithuriel's spear and brodiaea still exist in our Natural Areas. Today land stewardship often involves the protection of our natural heritage by preserving environments for other species.

What are invasive species?

Of the thousands of plants in the nursery trade, only a handful are considered to be "invasive" weeds. These plant species are capable of spreading rapidly and displacing native plants because they are adapted to similar climatic conditions, lack predators or pests and/or have other characteristics that make them thrive. Today, if left alone, our natural areas would contain only a handful of native plants and the animals that rely on the diversity of flora would go extinct. At this point in our history, the balance has been tipped by humans and natural areas cannot take care of themselves.

Does habitat restoration involve removing and planting trees?

Trees are important to wildlife because they provide nesting sites and hunting perches for birds and other animals. So as part of the preservation of bird habitat, for both resident and migratory bird species, the NAP will continue to plant trees, diversify, manage and protect forests. Native and exotic trees will continue to grow and be maintained within Natural Areas, because of the habitat and aesthetic values they provide. Native trees, like the coast live oak and the arroyo willow, not only provide superior food and habitat for wildlife, but also can co-exist with other native plant communities. By contrast, a few non-indigenous tree species are "invasive" and can be problematic under some circumstances.

When are non-native trees problematic?

First off, the tree must have invasive characteristics. Tasmanian blue gum (or blue gum eucalyptus), for example, has few natural predators, rapid growth rates and shades and poisons nearby sun-loving natives by exuding their own natural herbicides. Second the tree must be growing in a place where it can directly threaten a native plant community.

How many trees has NAP removed?

Tree removal in Natural Areas is selective. There are an estimated 25,000 trees in San Francisco Natural Areas. As of August 12th, 2002 the NAP has removed approximately 60 mature (greater than 6 inches in diameter) trees. These trees were removed to encourage the growth of our native coast live oak, trees, creekside willow, grasslands and/or shrub communities. The NAP does not clearcut, nor does it intend to remove entire groves of mature trees. Typically, small trees or saplings that are spreading into native habitat areas are thinned to allow sunlight to reach other plants and to improve the health of the entire ecosystem.

Is there poison oak in Natural Areas? What does the Natural Areas Program do about it?

Poison oak is very common in San Francisco Natural Areas. The Natural Areas Program continuously controls poison oak along trails in order to allow safe pedestrian access. Although poison oak is a native plant, the Natural Areas Program never plants it.

How can I experience Natural Areas?

Natural Areas are available to be explored by all. The Recreation and Park Department encourages you to visit these naturally beautiful places. Many San Franciscan's hike, walk, jog, fish and bird watch in Natural Areas. In some areas where the plants, animals or soils are fragile, in newly planted areas for example, access may be limited. It is estimated that access could be limited in less than 100 acres of land.

Can I bring my dog to Natural Areas?

Dogs and their human companions are welcome in Natural Areas. Off-leash dog recreation opportunities, which permit dogs to run free without fencing, exist or will exist in most natural areas. Some dog behaviors, such as digging and chasing wildlife, can be damaging to natural areas. Therefore it is important that dog owners be responsible for their pets activities. Please abide by posted park rules, clean up after your pet, prevent digging and wildlife disturbance and stay in designated areas. For more information on San Francisco's new citywide dog policy, please call the Recreation and Park Department at (415) 831-2700 or check the website.

How can we help preserve and protect natural areas?

As a visitor to a Natural Area you can help preserve these precious remnants by picking up trash and dog litter, minimizing soil disturbance and digging, respecting park rules and trail restrictions, not picking or planting flowers or trees or disturbing wildlife, learning about environmental stewardship and volunteering.

How can I volunteer or get involved?

The Recreation and Park Department has numerous on going and one time volunteer opportunities. To get involved or receive a free brochure call (415) 753-7268.

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