Invasive Plants: Impact on Biodiversity

Life in the City can be difficult for native plants and animals. Our local biodiversity crisis is caused by pollution, habitat loss, fragmentation and neglect, all of which severely impact local habitats for native wildlife and plants.

The San Francisco SIX
Take a Tour of the San Francisco Six with the new SFWMA brochure.

The number one destructive force on our local biodiversity is invasive species.

Invasive species are those that are introduced to an area they did not previously inhabit, where they exploit available ecological opportunities to spread rapidly and dominate. Some species were brought to San Francisco deliberately, such as South African iceplant to control erosion and Australian eucalyptus for lumber and windbreaks. Other “stowaways,” such as the European species of rat, came over in ships' holds. Of the thousands of introduced species, only some are invasive and destructive to San Francisco's natural heritage. These species take hold, spread rapidly, and if left unchecked, can displace our indigenous plants and animals.

The pesky subset of non-native plants known as invasive weeds are successful because they reproduce rapidly, are adapted to heavy disturbance, and find similar climatic conditions as in their home territories. When they arrive here, they do not come with their predators and pests to keep them in dynamic ecological balance.

The twin pillars of integrated pest management and community stewardship are the only way to manage invasive weeds in the city sustainably.

Learn about the Bradley Method of invasive weed control at Edgehill Mountain's website.

For more info about invasive plants & a list of priority weeds, visit: