Atlas of the Biodiversity of California

Title Page, Preface, and Table of Contents (PDF)(opens in new tab)

• Title Page
• Message from the Director
• Acknowledgements
• About the Artist
• Table of Contents

Biodiversity may be defined on many different levels. For a regional landscape or an entire state, it is the diversity of species, habitats, and vegetation types. For a habitat or vegetation type, it is the diversity of life forms within it. For a species, it is the genetic variation within a population or among populations.

A Definition of Biodiversity (PDF)(opens in new tab)

• A Definition of Biodiversity
• An Introduction to the Atlas
• About the Maps

To explain California’s biodiversity, we must first look at its geography, the basic physical systems that shape California. California is roughly 164,000 square miles in size with 840 miles of coastline. The size and interplay of active physical systems within California has resulted in a landscape of extremely varied geography: the highest and lowest elevations of the contiguous United States are both found in California. We can explain much about the biodiversity of the state by looking at its topography, geology, soils, climate, bathymetry, and ocean currents.

A Remarkable Geography (PDF)(opens in new tab)

• Climate and Topography
• Sea Currents and Temperature
• Bathymetry
• Geology and Soils
• Geography and Vegetation

Areas of high richness, rarity, and endemism are found in every region of California. Even within a taxonomic group, such as plants or mammals, one region may support the highest total richness of species because of its climate and resulting vegetation. Another may support the highest concentrations of special status taxa or endemics because of its rare local geology or its geographic isolation. Each region is unique in its contribution to the biodiversity of California.

Measures of Biodiversity (PDF)(opens in new tab)

• Vegetation Types
• Plants
• Special Status Plants
• Amphibians
• Reptiles
• Birds
• Mammals
• Freshwater Fishes
• Invertebrates

California supports resources of national and even international significance for biodiversity. From the rich kelp forests off the coast, to the unique populations of fishes in rivers, streams, and mountain lakes, to the isolated pupfishes of the deserts, California’s aquatic communities rival some of the most diverse. Yet California is best known for its terrestrial diversity, including iconic coastal redwoods found nowhere else on earth, characteristic oak woodlands of the coastal mountains and Sierra Nevada foothills, and seemingly hostile deserts that support an incredible diversity of life. The Central Valley features sweeping grasslands, colorful flower fields, and one of the most extensive distributions of vernal pools in the world.

Examples of Biodiversity (PDF)(opens in new tab)

• Kelp Forests
• Anadromous Fishes
• Coast Redwoods
• Oak Woodlands
• Wetlands and Riparian Habitats
• Vernal Pools
• Trout
• Mojave Desert
• Central Valley Grassland Habitat

California’s biodiversity faces many pressures. Most are linked to supporting the state’s large and growing human population. Threats to biodiversity are mainly due to the direct loss of habitat. In addition, fragmentation of habitat by developed infrastructure obstructs the movement of fish and wildlife and restricts their access to what habitat remains. A burgeoning population also places heightened demands on water, raises pollution, and increases the introduction of invasive plants and animals. Another growing threat to biodiversity comes from the rapidly changing climate, which in California means further reductions in water availability, rising sea levels, and more frequent extreme weather and wildfire events.

Threats to Biodiversity (PDF)(opens in new tab)

• Human Population and Land Use
• Human-Wildlife Conflict
• Stream Barriers
• Aquatic Invasive Species
• Terrestrial Invasive Species
• Climate Change

The people of California employ several strategies to conserve the state’s extraordinary natural heritage, both on land and at sea. These strategies include conservation planning, land ownership and stewardship, habitat restoration, and environmental law compliance. Government agencies, tribal governments, organizations, and individuals all cooperate in implementing these important protective measures.

Conserving Biodiversity (PDF)(opens in new tab)

• Lands Conservation
• Marine Managed Areas
• Habitat Connectivity
• Regional Conservation Planning
• Watershed Health
• Habitat Restoration

See this section for information on key words, references, and authors.

Glossary, Index, and References (PDF)(opens in new tab)

• Glossary
• References
• About the Authors
• Index