Why Native Plants Matter

California is a place of exceptional biological diversity. Many species that live here can’t be found anywhere else. Marin County alone has over a dozen species unique to this county, in plant communities that, in the space of a few miles, range from marine to coastal to higher elevation habitats.

Many native plant habitats in Marin are under siege. They are threatened by the spread of destructive invasive species such as broom, pampas grass and yellow star thistle; by recreational uses that degrade native plant habitats; by rapid climate change that exceeds their ability to adapt; and by the lack of understanding of the importance of preserving native plants and habitats for biodiversity. In addition, we have long ignored natives when it comes to planting our home gardens. Imported exotic plants dominate gardens and public spaces everywhere in the county.

Plants are the foundation of the food chain, the only living thing that can convert the sun’s energy into carbon and capture it so other living things can then access it. Insects are the next level of the food chain. When they eat plants, they perform the essential function of converting plant carbon into animal protein. This can wreak havoc on plants. However, insects also serve as the most important pollinators of the plant world. Plants thrive when they find a way to balance the competing forces that attack and support them: they must repel predators to avoid being eaten while attracting pollinators in order to reproduce. Rooted in the ground, they can’t run away from creatures that would eat them like animals do. As a result, the plant world has developed a dazzling array of chemicals both to repel predators and attract the right pollinators.

We are completely dependent on this plant-insect symbiosis. Plants provide oxygen, transfer carbon from the air to the soil, and feed, directly or indirectly, most creatures above them in the food chain. Insects that feed on plant pollen and nectar often pollinate them in the process. Three quarters of our food crops depend on insect pollinators. Although humans use pesticides to destroy insects and a planet with less insects may seem like an improvement, our survival is tied up with insects: they are essential to maintain the ecosystems that support humans. If they don’t thrive, we don’t either.

It has taken millions of years of evolution for native plants and insects to develop these relationships and the plant chemistry on which they depend. These co-dependent relationships are why the loss of native plants in the wild and in our gardens is so critical. Most California insects have developed a symbiotic relationship with specific native plants and are unable to thrive and reproduce in their absence. Even non-native plants that have been here for 200 years are not seen as a food source by many insects. Honeybees are a non-native insect so they do well, but California’s 1500 species of native bees are struggling to find food resources, as are our bird populations, which are highly dependent on native insects, especially caterpillars, to feed their young.

The Marin Chapter of the California Native Plant Society works to protect our native plants and habitats. We welcome and need volunteers interested in helping to ensure that the native plants we enjoy in the wild continue to exist and flourish. Our work takes many forms: demonstration gardens to showcase natives and fire-smart garden techniques, public education about natives, work with schools, spring and fall plant sales, comments on public land use plans affecting native plants, work with public land managers and other non-profit organizations to conserve and restore native plant habitats, and much more. Please explore our web site to find out more about our work and how you can get involved.