Mapping the Hidden Forest

Cami Pawlak’s Tree Heat Maps and California’s Living Diversity

In the mosaic of California’s ecosystems—from alpine ridges to coastal fog belts—a quiet revolution is happening in the way we see and understand our trees. At the heart of this transformation is Camille “Cami” Pawlak, a scientist and cartographer, whose range maps and species richness heat maps breathe new life into our understanding of tree diversity across the Golden State.

As co-author of the groundbreaking paper California’s Native Trees and Their Use in the Urban Forest and cartographic contributor to the new book California Trees by Matt Ritter and Michael Kauffmann, Pawlak helped create a tapestry of native tree knowledge: 95 meticulously mapped species, each one traced to its native extent in California.

A Forest in Pixels

Pawlak’s digital work is a fusion of rigorous science and ecological storytelling. She built species richness heat maps by layering the native range of each tree across California’s varied topography. The result? A vibrant visualization of biodiversity that highlights California’s tree diversity like never before.

One of the brightest pulses on this heat map is in Robert Louis Stevenson State Park, where the convergence of species is so rich, it holds the highest concentration of endemic tree species in the state—eight species found only in California. Her work brought this hidden biogeographic truth into focus.

A Living Library: The Trees of Robert Louis Stevenson State Park

Tucked in the Mayacamas Mountains, this park is a refuge for California’s arboreal soul. Thanks to Pawlak’s range mapping, the following tree species are confirmed here:

Endemic Tree Species (Found Only in California):

• Aesculus californica – California buckeye
• Hesperocyparis macnabiana – McNab cypress
• Hesperocyparis sargentii – sargent cypress
• Pinus attenuata – knobcone pine
• Pinus sabiniana – ghost pine
• Quercus agrifolia – coast live oak
• Quercus douglasii – blue oak
• Quercus kelloggii – California black oak
• Quercus lobata – valley oak
• Quercus wislizenii – interior live oak
• Sequoia sempervirens – Redwood (yes, a few are in Oregon)
• Torreya californica – California Nutmeg

Other Native Trees of the Park:

• Acer macrophyllum – Bigleaf maple
• Alnus rhombifolia – White alder
• Arbutus menziesii – Pacific madrone
• Calocedrus decurrens – Incense-cedar
• Chrysolepis chrysophylla – Giant chinquapin
• Cornus nuttallii – Mountain dogwood
• Notholithocarpus densiflorus – Tanoak
• Pinus lambertiana – Sugar pine
• Pinus ponderosa – Ponderosa pine
• Pseudotsuga menziesii – Douglas-fir
• Quercus chrysolepis – Canyon live oak
• Quercus garryana – Oregon oak
• Salix laevigata – Red willow
• Salix lasiandra – Pacific willow
• Umbellularia californica – Bay laurel

From Wild Slopes to Urban Streets

Beyond the wild landscapes, Pawlak’s work plays a practical role in shaping resilient urban environments. She helped build city-specific native species lists using these same range maps—allowing city planners, arborists, and homeowners to choose trees that truly belong, ecologically speaking.

This matters immensely as California cities confront hotter, drier futures. Many native trees—especially those endemic to mountain or riparian environments—might not be suited to lowland cities. But thanks to Pawlak’s work, those decisions can now be made based on real data, rather than assumption.

Cami’s research found that native trees are underrepresented in California’s urban landscapes. Although she identified 95 tree species native to the state, only 76 of them occur within city boundaries, and just 75 are currently planted as urban trees. On average, California cities have only 6.89 native species within their boundaries, and many have far fewer—some none at all. Native trees make up just 7.74% of individual trees and 3.18% of species in city tree inventories. Furthermore, most urban centers were established in regions that naturally support fewer native trees, such as valleys and coastal scrublands. She also noted that many native species have moderate to high water needs, which may limit their future suitability in drought-prone cities. Overall, her work highlights both the ecological constraints and the limited opportunities for expanding native tree diversity in urban California

Rooted in Place, Growing Forward

Camille Pawlak’s contributions are not just scientific—they are visionary. Her work gives us tools to see California not only as it is, but as it was and might yet be again. Through her range maps and species richness data, we see that even in an era of climate uncertainty, there is deep value in knowing what has always grown where.

Whether you are hiking among the ancient canopies of Robert Louis Stevenson State Park or planting a street tree in downtown Los Angeles, you are part of the same ecological story—a living, growing narrative made clearer by the work of scientists like Cami Pawlak.

Explore the Maps in the Urban Forestry Ecosystem Institute

🔗 Discover which trees are native to your wildlands, city,  or parks

Let the forest guide your choices, whether for conservation, rewilding, or simply knowing the names of the neighbors in your local grove.