A rutted dirt road emerges from a dense thicket of Douglas fir on San Juan Island’s Cady Mountain. Patches of scorched earth heal from fires that swept through the Garry oak savanna last summer. Green wildflower shoots break the surface of the blackened prairie. The oak savanna habitat on Cady Mountain has begun to reappear after more than a century of hiding.
Were it not for 100 years of fire suppression, more oak savanna and prairie ecosystems would be present on Cady Mountain. But without a natural force like fire to keep opportunistic species in check, Douglas fir have colonized these ecosystems and threatened the mountain’s biodiversity. Thom Pence, a retired forester living on Cady Mountain, is working to restore oak and prairie habitat and would like to reintroduce fire to the landscape. A Natural Resources Conservation Service grant funds Pence’s restoration project. The grant covers some of the cost of removing non-native species and planting native vegetation, but the service does not support his desire to prescribe controlled burns to the mountain.
"These are fire-generated ecosystems," Pence said. "Without fire, restoration is impossible."
Natural fires and those intentionally set by American Indians for agricultural purposes played a vital role in maintaining oak savanna and prairie habitat. Frequent, low-intensity fires curbed conifer encroachment and promoted the growth of native prairie species.
With the presence of periodic fire, grasses and wildflowers dominate the the prairie ecosystem. As Europeans suppressed fire from the ecosystem during the past 100 years, prairies and oak savannas have nearly disappeared throughout the San Juan Islands.
"It was incredible," Pence said, recalling the moment he discovered the large Garry oak population on his property. "So much was hidden by the forest that I didn’t even realize (the oaks) were out there."
Pence discovered a large number of oaks on Cady Mountain when he moved there in 1999, but most of the area was overgrown with Douglas fir trees.
"We are literally swimming in a sea of Douglas fir," said Peter Dunwiddie, the director of research programs for The Nature Conservancy. "They are very effective at invading prairies."
Dunwiddie said considerable acreage on Cady Mountain was historically grassland and oak savanna; the site, however, has been severely degraded. Eighteen of the 29 grass species on Cady Mountain are non-native grasses that were planted to support livestock grazing.
Pence said extensive restoration, including removing Douglas fir trees and reintroducing fire to the landscape, is necessary to turn the tide of succession.
"Prairies are a fire-maintained community," Dunwiddie said. "From a conservation perspective, if proactive steps are not taken to restore the community, the native biodiversity will be lost."
Fire maintains the structure of the site and holds back Douglas fir seedlings. Many of the non-native grasses, however, respond well to fire, and burning could facilitate unwanted growth.
"We will probably never get back to a natural habitat," Pence said, crouching down and pointing to tiny fir seedlings sprouting up amid the dead winter grasses. "These guys are growing uninhibited and will continue without the use of prescribed fire."
The Nature Conservancy identified the prairie ecosystem as one of the most crucial habitats for conservation in Western Washington because of its biodiversity.
Pence funded the first three years of restoration himself and performed all the manual labor. He involved neighbors when he found out he could receive federal grants for the restoration effort.
The site now includes approximately 175 acres.
In October 2003, Pence received a $160,000 grant from the Natural Resources Conservation Service. The grant pays 75 percent of the cost to remove conifers and invasive species and plant native grasses during a 10-year period. Although the service identifies prairie ecosystems as one of the most biologically diverse west of the Cascade Mountains, the grant does not fund burning.
Rachel Maggi, the west area biologist for the Natural Resources Conservation Service, said that while it supports prescribed burns in other states, the service’s policy prohibits the funding of burning in Washington state for legal and safety reasons. The Department of Natural Resources considers Cady Mountain a high-risk area for fire.
Pence said further efforts to fund burning have come up short.
"It’s ironic," Pence said, shaking his head. "This is a fire-dependent ecosystem, yet we can’t get funding for fire."
Pence, who retired in 1999 after 30 years in the U.S. Forest Service, said he is the only landowner on the mountain with experience in fire ecology.
After burning small areas on his property, Pence said he has seen wildflowers grow back more densely. In the spring, Cady Mountain is painted with deep purple shooting stars and camas and bright yellow buttercups, all native prairie flowers.
"It’s the eye candy — the wildflowers and the wildlife," Pence said. "If we could bring back the blue birds or butterflies, it would be a saving grace to the project."
Dunwiddie said it might not be realistic to completely restore Cady Mountain to its native grassland habitat because it lacks the density of native species. Cady Mountain might only have three to five native species per square meter, Dunwiddie said.
Yellow Island, however, has more than 20 native species per square meter.
The Nature Conservancy bought Yellow Island, which is tucked between Shaw and San Juan islands, in 1980. Dunwiddie said its vision was to restore the landscape to a prairie dominated by grass species.
Yellow Island’s native prairie survived because the 10-acre island was too small for agricultural use and has no fresh water. Evidence also indicates that American Indians burned on Yellow Island.
The Nature Conservancy’s goal is to use fire on Yellow Island to mimic the historical regime and produce specific results. The Nature Conservancy has refined its ecological goals for Yellow Island since restoration began in 1998.
Phil Green, the Yellow Island Preserve steward, said that when restoration began, the focus was clearing native snowberry and ocean spray bushes, which had grown more dense in the absence of fire.
Green said Douglas fir is a native species in prairie habitats but did not exist in thick stands with the presence of fire. The firs on the island are "lone wolf" trees; they grow in an open environment as single trees, with branches spreading widely to the ground. Several 200- to 300-year-old conifers grow on the island.
After 20 years of restoration and the return of fire to the ecosystem, a greater diversity of native flowers has emerged.
"The goal is not to achieve a snapshot but to perpetuate a dynamic landscape which keeps changing over time," Dunwiddie said.
In 2002, The Nature Conservancy put a regular burn schedule into place. Green said the conservancy burns roughly one to two acres annually and is working to instill a five- to six-year fire cycle.
Dunwiddie said no answer is clear as to what the desired future condition is because no truly native prairies still exist, and historical data records do not go back far enough to determine the island’s original state. The goal of The Nature Conservancy is to protect the best example of the native biodiversity that once existed on the San Juan Islands.
"Even if it is considered unnatural, we must restore fire management to sustain the community," Dunwiddie said. "We will lose great species biodiversity if we don’t."
Restoring grasslands is only the beginning to restoring the degraded landscape. More unidentified plants and animals exist in the ecosystem. Dunwiddie said it is a great challenge to restore an ecosystem when only a small percentage of what the community once consisted of is known.
Since prairies consist of more than plants, Dunwiddie sees replanting and burning as only the beginning. The return of other species will mark the success of the restoration.
"It’s not a build-it-and-they-will-come situation," Dunwiddie said. "We’re missing the big picture and hoping the rest will come.