Mapping the present for the future: A regional coalition of land agencies coordinates an ambitious Marin County project

By Kathy Morrison

Certainly, it is a mountainous task: Map every bit of the vegetation in an 828-square-mile county that’s a biodiversity hotspot.

But imagine the invaluable resource that results from such a project. The high-detail map could be used to study plant communities, to plan for flooding, to site least-invasive development plans, or to track the reduction or growth of tree canopies. It would be useful for emergency management as well as for recreation planning.

The peaks and canyons may be the site of 200 miles of trails, but they also are home to more than 750 native plant species and 250 native animal species.

Marin County is the focus of just such a task, thanks to the Tamalpais Lands Collaborative (TLC), a forward-thinking coalition of regional land management agencies and one nonprofit agency, and its public outreach initiative, dubbed One Tam. CNPS also is part of the mapping project.

Tam, of course, refers to Tamalpais, the 2,571-foot mountain that dominates Marin’s landscape. Concern for the future of the beloved peak and surrounding lands inspired the creation of the coalition.

“Over the years there’s been growing recognition that issues we all face are the same issues, none of which stop at our borders,” says Janet Klein of the Golden Gate National Parks Conservancy, a nonprofit partner of the Golden Gate National Recreation Area (GGNRA). Among these concerns she cites are invasive species, climate change, drought, forest disease, and risk of catastrophic wildfire. “We’ve all realized the need to scale up our work and become more efficient in what we do. Collaboration is a huge way to get there.”

In addition to the Parks Conservancy and the GGNRA/National Park Service, the TLC includes the California State Parks, Marin County Parks, and the Marin Municipal Water District (MMWD). The four land management agencies all own adjoining lands on Tam, Klein explains. The TLC’s defined area of focus is roughly 46,000 acres, covering all of Mount Tamalpais State Park, Muir Woods National Monument, and the water district’s watershed lands, plus parts of the GGNRA and several of the Marin County open space preserves.

“We’ve all been working together for years,” Klein explains. Cross-pollination of staff and ideas is common. “We will share equipment and we will share expertise. But it’s always been ad hoc, project by project, or need by need, and it’s not always 100 percent smooth.” Lack of staffing or funding sometimes exacerbates difficulties.

Creating a coalition

It’s no stretch to say that Marin County residents are passionate about their open space, which in many cases is right next to their homes. Mischon Martin, chief of natural resources and science for Marin County Parks, notes that park lands include 34 open space preserves, which border 3,400 backyards. One poll she cites showed that 88 percent of park users live within a mile of a preserve. “We love our lands to death,” she says.

Klein says the push behind the Tam coalition was California’s State Parks budget crisis of several years ago, when initially as many as 70 of the 278 parks were scheduled to be closed. Mount Tamalpais State Park was not on that list, but to keep the park operational, the State Parks opened up to what she calls more creative thinking on resources, putting together the Redwood Creek Initiative with the National Parks Service and the GGN Parks Conservancy.

About the same time, Klein says, the MMWD was exploring the idea of creating its own nonprofit organization, a more modest version of the Parks Conservancy, to protect and support the 36,000 acres of public land it manages.

The report also revealed many gaps in knowledge about the mountain. Surveys were needed on Tam’s insects, for example, as well as its lichens, bats, small mammals, riparian and hardwood forests and woodlands, soils, and hydrologic functions.

The Parks Conservancy took a look at all of this and approached the four land management agencies with
the idea of the Tamalpais Lands Collaborative. The partnership was formalized in 2014, and the members put together a five-year strategic plan, an aspirational list of projects, Klein says. “It was far more than we thought we could accomplish at the outset, but it set the bar,” she says.

One Tam is the TLC’s public campaign to guarantee that the mountain, which receives 5 million visitors annually, remains healthy. The peaks and canyons may be the site of 200 miles of trails, but they also are home to more than 750 native plant species and 250 native animal species. Tamalpais has thousands of acres of serpentine soils and other special habitats for rare plant species.

Among its ongoing programs in tandem with coalition members, One Tam facilitates regular habitat restoration workdays, coordinates a bat monitoring project, monitors wildlife via motion-activated cameras, offers youth stewardship training, and hosts an annual science symposium. The One Tam Weed Management Program is a coordinated effort of the TLC agencies to keep native landscapes pristine.

Meanwhile each of the collaborative’s members maintains authority over its own lands and projects, Klein says. One agency’s decision on dog access, for example, does not automatically apply across the other members’ lands. Resources and information are shared, but individual goals and mandates are retained, she explains.

A vegetation map plan sprouts

In 2016, the collaborative completed a key baseline ecological report on Mount Tamalpais, its wildlife, plants, and landscape, combining previously existing data from each of the member agencies. “Measuring the Health of a Mountain: A Report on Mt. Tamalpais” concluded that the mountain’s overall health is fair, with certain indicator communities — the coho salmon and the foothill yellow-legged frog — in poor health. Of the plant communities, the maritime chaparral is in poor health, while the Sargent cypress and shrublands communities are in good health, the report noted. The other plant communities fall in between, rated fair.

But the report also revealed many gaps in knowledge about the mountain. Surveys were needed on Tam’s insects, for example, as well as its lichens, bats, small mammals, riparian and hardwood forests and woodlands, soils, and hydrologic functions. California giant salamanders, the report notes, are excellent indicators of stream health and need to be studied, along with the mountain’s seeps, springs, and wet meadows. The Douglas-fir forests, too, need to be monitored, especially encroachment into other habitats in the wake of fire suppression, the report concluded.

What went before

It was at this point that TLC agencies realized they needed a complete, updated vegetation map of the mountain lands. “A vegetation map is more than just a two-dimensional map,” Klein explains. “We always mean it’s a spatial data set that gives us very detailed descriptions of the vegetation types and communities that are found on Mount Tamalpais.”

Parts of Marin have been mapped previously, notes CNPS Vegetation Program Director Julie Evens. For instance, old aerial maps exist of the western part of the county. The National Parks Service created an early detailed map of Point Reyes National Seashore, she said. Andrea Williams, vegetation ecologist with the MMWD, says the water district is unique among the partners because it has mapped its watershed three times since 2004, particularly to track the spread of Sudden Oak Death (SOD). And Marin County Parks has a vegetation map of its open space, completed in 2008, Martin says. The State Parks only had tiny pieces of its land mapped as part of the other efforts, Klein notes. Other maps of the county, such as fire and fuels maps, had been done in different ways and were very low-resolution, she adds.

This patchwork collection of available maps, created at different times, does not lend itself to a full understanding of Tam and its living world. “They’re difficult to knit together,” notes Williams. And vegetation, of course, does not stop at boundaries.

“So this was a great example of what the collaborative could do together,” Klein says. The water district was the next of the members with plans to update its map. “So all the other partners lined up, and with that backbone support from the Parks Conservancy, the decision was that we would all go together in 2019.”

Once that conversation started, local excitement picked up, with the agricultural community and fire community expressing interest, Klein says. Finally, the collaborative decided to consider mapping the whole county.

The model for a comprehensive map could be found just to the north. Sonoma County was already well into the process of creating a vegetation map. And Martin says that in exploratory meetings with Sonoma, Marin officials were advised, “If you can do it, do countywide and do LiDAR.”

Call in the LiDAR

LiDAR is a surveying method that measures distance to a target by illuminating the target with pulsed laser light and measuring the reflected pulses with a sensor. “What it starts to give you is vertical profiles of the landscape and the vegetation, bouncing back up,” Klein says. The fine-detail LiDAR produces 8 points of return per square meter, far beyond what the partners have had it in past.

The most recent county parks map used a very coarse LiDAR, Martin says. The high-quality LiDAR to be used in the all-county map is fine enough to view plant communities beneath tree canopies. She notes that in Sonoma County areas where GPS units don’t work well, this level of LiDAR was able to detect old, overgrown logging roads and trails, which can be a boon for parks planners or roads departments.

Sonoma County posted its completed vegetation map online in June 2017. (It can be viewed at sonomavegmap. org.) Just four months later, wildfires erupted in several corners of the county, scorching thousands of acres and killing several dozen residents. A post-fire assessment and update of the map is in progress.

Expanding the map project

Jumping from mapping Mount Tamalpais to mapping the entire county would not have been possible without broad local support. Fortunately, there was enough of a ground-swell to do it all at once, Evens says. Coalition members presented the idea to officials from such agencies as public works, which manages the creeks, and MarinMap, the county’s system of GIS data. “Surprisingly, everybody was excited about the idea,” Martin says. That enthusiasm included willingness to chip in funding.

Marin County Parks itself is contributing $100,000 just this year, Martin says. That funding is possible thanks to Marin’s quarter-cent sales tax, Measure A, approved in 2012. The Parks Conservancy also identified some private philanthropic sources for funding, Klein notes. U.S. Geological Survey funds, tagged for low-resolution mapping, also became available to support the high-res project.

I couldn’t imagine making the decisions we make without this. This is one of the most exciting things we’ve done in a really long time.”
— Mischon Martin, chief of natural resources and science for Marin County Parks

Making the map

The Marin project kicked into gear this past summer, first with high-resolution aerial photography, then with the LiDAR, Klein says. These images will become the base to which data collected in the field are added. Evens’ team at CNPS is aggregating more than 1,000 points of pre-existing data from previous field work in Marin to create a vegetation classification system.

Over the summer, preliminary groundwork had crews spot-checking old data as well as gathering wetlands data, Klein says. A more extensive schedule of ground data collection is planned next year. After classification adjust-ments and other computer and human analysis, a draft map is expected to reach the agencies in early 2020. It will take another year of ground verification before a final map is released.

The map information will open up all kinds of possibilities for the coalition partners and for the county. It will inform decisions such as hydrology planning, habitat restoration, and land use. “I couldn’t imagine making the decisions we make without this,” Martin adds. “This is one of the most exciting things we’ve done in a really long time.”