Natural Features & Ecosystems

 

NPS

Climate

Climate greatly influences the types of plants and wildlife found in an area. Located in the east San Francisco Bay area, John Muir National Historic Site is within the Mediterranean climate region of California. This Mediterranean climate zone occurs along the central and southern coastal areas of the state, where cool breezes come in from the Pacific coast and hot air is pulled from the interior portions of the state. Found in very few other places around the world, the Mediterranean climate is typically characterized by dry, hot summers and wet, mild winters.

For information on how climate change will affect plants and animals at John Muir National Historic Site, visit our climate change page.

Geology

Mt. Wanda elevation: 650ft
The rock that makes up Mt. Wanda and the area around it is mostly marine sedimentary rock that was formed during the Cretaceous period 145- 66 million years ago. This sedimentary rock was created when weather and erosion broke down rocks on land into particles (sediment) that eventually settled on the ocean floor and was compacted into rock under that immense weight and pressure . Over time, the movement of tectonic plates pushed this rock out from under the water to create the rolling hills of Martinez, including Mt. Wanda. To learn more, check out this geologic map of California from the California Department of Conservation.

How does the geology of Mt. Wanda affect the plants, animals, and ecosystems we see?

Different types of rocks in an area determine which kind of soil is formed there. In turn, the type and composition of soil in an area impacts the vegetation that grows there, which then affects the types of animals that live there. The soil on Mt. Wanda is mostly loam and clay loam. Loam is nutrient rich with relatively loose texture and moderate water retention. Clay soil is lower in nutrient richness, but has a high potential to retain water. The combination of these two soils supports the diverse natural communities seen on Mt. Wanda, which tolerate a wide range of water availability.

Ecosystems

An ecosystem is a biological community of interacting organisms, and their physical environment. Within ecosystems, there are different natural communities with unique combinations of plants and wildlife. On Mt. Wanda, there's an opportunity to see a variety of natural communities on a single day’s hike. The main trailhead at the northern section starts with bay laurel forest, then transitions to an oak woodland, followed by more open savannas and grasslands. Shrublands can also be found on site in more remote locations. To learn more about these communities, check out our plants page.