Faster-than-average warming is bringing changes to Richmond’s ecosystems. Temperatures and sea levels are rising. Fog patterns are shifting. Richmond’s plants and animals are facing a future of altered habitats.
Anna’s hummingbird feeding on pallid manzanita nectar in a stand of maritime chaparral at Sobrante Ridge Regional Preserve
To the west lies 32 miles of shoreline, the longest of any city in the Bay Area. To the east lie the hills: Sobrante Ridge and Wildcat Canyon. These open spaces contain salt marshes, subtidal zones, evergreen forests, coastal prairie and chaparral. Shorebirds, raptors, mammals, fish, and invertebrates call Richmond home.
As part of a comprehensive study on human-caused climate change at National Parks published this fall, Patrick Gonzalez, a climate change scientist and forest ecologist at the University of California, Berkeley, looked at historical and future climate data at Rosie the Riveter WWII Home Front National Historic Park in Richmond.
Gonzalez said he found, “significant warming in Richmond, greater than the national rate and greater than the global rate.” Over the last century, from 1895-2010, the temperature has increased by 1.2 degrees Celsius, or 2.2 degrees Fahrenheit.
“If we don’t reduce our carbon production from cars, power plants and other human sources,” he said, temperatures at the Rosie the Riveter WWII Home Front could by 2100 increase by three times what it has already risen during the past century. “That would mean a rise of another 3.8 degrees Celsius, or 6.8 degrees Fahrenheit,” Gonzalez said.
Shorebirds feeding at the Dotson Family Marsh
Along the Shoreline
On a recent Saturday morning, bird watchers from all over the bay gathered at the Albany mudflats for a Golden Gate Audubon Society field trip. By ten minutes before 9 o’clock, nearly everyone had already arrived, quietly lined up on the viewing platform and aimed their spotting scopes toward the water. A “list keeper” was designated and Birders began calling out what they spotted: one long billed curlew, two American wigeons, one American avocet, 500 western sandpipers, two brown pelicans. Intact intertidal zones in the East Bay support some of the richest bird habitats in the world.
The San Francisco estuary is the largest on the west coast of North America. Although the Bay Area has already lost 80 percent of its tidal marsh, it is still home to the majority of tidal wetlands in the state.
“Tidal marshes are a lot like a sponge. They soak up water and help protect against sea level rise and they filter pollutants. They are super diverse productive systems,” said Julian Wood, the San Francisco Bay Program Leader at Point Blue.
The northern part of the Richmond shoreline is undeveloped and home to marsh habitat that thrives at Point Pinole and Point Molate. Michele Hammond, a botanist at the East Bay Regional Park District, said Whittell Marsh is home to the federally endangered soft bird’s-beak, a salt tolerant annual herb with spike shaped clusters of flowers. Salt marshes provide habitat for hundreds of species of migrating and year-round shorebirds and are home to pickleweed and the endangered salt marsh harvest mouse. They also help to filter runoff, keeping the bay healthier.
But Bay Area salt marshes like these could soon be forced up slope or disappear. Gonzalez and his team used data from a tidal gauge located offshore near Crissy Field in Golden Gate Park to gather historic sea level data, noting we could expect the trends in Richmond to be similar. “Human caused climate change has raised sea levels by an amount that would come halfway up to your knee, about 22 centimeters,” or nine inches, Gonzalez said.
Future sea level projections indicate it could rise by an amount that would come between your knees and your hips. “If we don’t reduce our carbon pollution, then continued climate change could raise sea levels another 75 centimeters,” or about 30 inches, by 2100, under the highest envisioned scenario, Gonzalez said.
“Any continued sea level rise threatens inundation of coastal areas,” he said.
As sea levels rise there are two ways for marsh habitats to adapt. “They can increase their elevation vertically through sediment accretion or move landward and shift upslope,” Wood said. The newly restored Dotson Marsh at Point Pinole was designed to accommodate these processes.
Lech Naumovich, executive director of Golden Hour Restoration, a non-profit focused on restoring native plants and habitats, said that many intact marsh habitats like at Point Molate are up against concrete so there is no room to move upslope.
In some coastal areas, “you have intact marsh and then, ‘Boom! Development,’” Naumovich said. “If sea levels rise, the marsh habitat could disappear underwater, becoming subtidal, and there would be no way for the replacement marsh habitat to move upslope,” he said.
According to V. Thomas Parker, a biologist at San Francisco State University, at the current rates of sea level rise and sediment accretion, marsh habitat can keep up but if sea level rise accelerates and sedimentation declines, “there is a threshold projected to be around 2050 where they will become mud slabs. They will drown,” Parker said.
The National Oceanic and Atmospheric Administration has created maps for visualizing sea level rise. To view which areas of Richmond could end up submerged under Gonzalez’s scenarios, drag the sliders between two and three feet.
American Avocet at the Albany Mudflats. This species is listed as climate endangered by the Audubon’s Bird’s and Climate Change Report.
Fog at Sobrante Ridge Regional Preserve
Shifting Fog Patterns
The Bay Area’s climate is characterized by fog, and many plants have evolved to depend on it. Understanding how climate change is impacting fog patterns is complex and is an area of active study. Several recent studies have indicated that there is a trend toward fewer fog days in the Bay Area, according to the California Climate Assessment, released in August of 2018.
The first significant rain of the season landed softly on the leathery green-gray leaves of the pallid manzanita. The plant’s twisted dark maroon bark glistened with water droplets. Fresh milky-white flowers covered two of the manzanita plants. Lichens and moss turned bright green from the moisture. Anna’s hummingbirds had appeared in full force congruently with the manzanita blooms: they chirped and chattered and swooped down to drink pallid manzanita nectar. The Pallid manzanita is the defining species of a plant community called maritime chaparral.
“Maritime chaparral,” named because it thrives in marine influenced climates, is a California plant community that depends on fog. The plant community is a rare ecological type and can only be found in a handful of places in the East Bay, one of which is at Sobrante Ridge Regional Preserve just beyond Richmond’s borders. The Sobrante Ridge maritime chaparral plant community is also home to brittleleaf manzanita, shreve oak, interior live oak, madrone, western bracken fern and sticky monkeyflower.
The pallid manzanita is a “classic fog species,” said Parker. It has a lobe shaped leaf base called “auriculate” because it looks like an earlobe. “You have a super rare plant with similar morphology to other rare plant species only found in fog,” said Parker.
Hammond, the botanist at the East Bay Regional Park District, said that the few remaining stands of maritime chaparral are fragmented and highly degraded. “As we lose the fog, we lose our maritime chaparral,” Hammond said.
Decreasing fog is just one of the challenges this plant community is facing. It is also declining because fire suppression activities are preventing the plant from successfully reproducing and because a soil borne pathogen is weakening the remaining populations.
Naumovich, who is working with the park district to restore pallid manzanitas, said “maritime Chaparral in the East Bay could be gone in the next 30 years. Healthy juvenile populations of pallid manzanita can be found in fewer than five locations across the range of this plant.”
Lichens at Sobrante Ridge Regional Preserve. Lichens tend to grow in areas that receive summer fog.
Urban Wildlife Corridors
“Some wildlife species may need to shift locations as the vegetation they inhabit moves with a changing climate. Barriers to movement are substantial due to habitat fragmentation and urbanization,” according to the August publication of the Fourth California Climate Change Assessment.
Diana Benner, vegetation ecologist at the Watershed Nursery, a Richmond-based plant nursery specializing in growing California native plants, said, “our philosophy at the nursery is that having healthy plant communities with diverse genetics will increase the chance that plant species will be able to either adapt or disperse to climate change conditions. Having as much connectivity as possible in the form of urban wildlife corridors, like the Richmond Greenway or even individual gardens, can contribute.”
Plantings along the Richmond Greenway
Changes in Seasonal Timing
Doug Bell, wildlife program manager at the East Bay Regional Park District, said that the park district is working to better understand how climate change is impacting wildlife. Bell has been studying the impacts of drought on golden eagles in the Diablo range. He said, “we are looking at responses of wildlife populations to wide swings in weather patterns, such as the swings from wet to drought conditions.” If we do have more incidences of high variability as we move into the future, he said this could have impacts on wildlife.
“The timing of seasonal events, such as flowering or insect emergence, is highly sensitive to climate and offers important opportunities for monitoring biotic responses and engaging citizen science,” according the California Climate Assessment.
Tom Kelly, co-director of Greens at Work, a native plant revegetation project at Point Isabel, said he sees lots of different birds that are stopping over at Hoffman Marsh to feed and rest during their migratory route on the Pacific Flyway. Kelly said he has observed anecdotally that some plants and native grasses are flowering earlier. “If plants are flowering, going to seed and producing food for birds at a time that is not synced up with the time birds are coming through, then there could be a reduction in bird populations. The timing is really important. They could go hungry,” Kelly said.
Gonzalez said there is still time to alter the course of this trajectory. “The good news is with renewable energy, energy conservation and other available practices to reduce carbon pollution, if we meet the Paris Agreement goals, we can limit the projected temperature increase to 1.4 degrees Celsius, or 2.5 degrees Fahrenheit, half of the heating under the highest scenario,” he said.
“We could also limit sea level rise to 50 centimeters,” or about 30 inches,” Gonzalez said.