Nurseries put in place for the logging industry are now responsible for restoring native species to national forests across the country.

— by Jane Braxton Little

In a back room at the U.S. Forest Service nursery in Placerville, California, dozens of small glass bottles containing seeds are arranged in wooden cases like a horticultural sampler. Each one cradles the future of a native species: ponderosa and Jeffrey pine; incense-cedar and red fir; aspen, antelope bitterbrush, and curl leaf mountain mahogany. Some seeds are as big as blueberries, others smaller than the head of a pin. Some are round, some angular, others flat flakes. There are black seeds, beige seeds, blood-red and two-toned seeds. Leaning against the table are waist-high burlap sacks containing sagebrush, ceanothus, and bitterbrush seeds.

This small room holds the promise of survival for native plant species from the giant sequoia to the stemless dwarf lupine. Here and at other facilities in the Forest Service nursery network, plants threatened with local extinction are collected, catalogued, and stored. When wildfire, flood, hurricane, or insect infestations destroy a species in the wild, workers germinate these safely stored seeds. This federal nursery system is a botanical ark, the nucleus of the agency’s mission to restore and retain ecosystem health throughout its 193-million-acre domain.

Seeds being germinated by a Forest Service nursery (Credit: Jane Braxton Little)

“We’re not just growing the traditional species anymore. Today it’s all for restoration—100 percent,” says Monty Maldonado, a Forest Service forester in charge of nurseries, reforestation, and genetics. Restoring native species is a new mission for the agency known for decades of clearcutting. In the 1980s, when timber production drove the Forest Service, annual timber harvests ballooned to 14 billion board-feet— enough to build 140,000 houses. Fourteen nurseries across the country were busy sprouting 100 million conifer seeds a year to replant denuded hillsides. But in the 1990s, when timber harvest levels dropped to 4 billion board-feet, nursery production plummeted, too. Without seedlings to grow for planting on vast stretches of clearcut lands, the federal nursery system faced an uncertain future. How it responded has not only benefitted today’s national forests and grasslands; it also ensures the future of biological diversity on federal lands.

 

A CENTURY OF SEEDLINGS

The Forest Service began growing seedlings even before the agency was formally sanctioned. The first nursery was in the grass-covered Sandhills of Nebraska. Approved in 1902 by President Theodore Roosevelt, it was initially designed to provide trees as building materials for homesteaders settling on lands that had few natural forests. Within a decade, however, indiscriminate harvesting and enormous fires justified the creation of what Maldonado calls “a man-made forest.” The Nebraska nursery shipped thousands of conifer seedlings to Montana, Idaho, and Wyoming. It did not seem to matter to these early nurserymen that the cones that bore the seeds for these young trees came from thousands of miles away.

The number of Forest Service nurseries expanded in the 1930s to accommodate President Franklin D. Roosevelt’s programs to get America working again after the Great Depression. The Civilian Conservation Corps planted three billion seedlings to mitigate soil erosion and enhance timber resources. Not all the plantings were sensitive to native ecosystems, but the programs employed over three million out-of-work men. After World War II, the demand for timber created the boom years for America’s timber industry. Harvesting on national forests tripled from 1950 to 1965 and held steady at an annual yield of around 10 billion board-feet into the early 1990s.

These were boom years for federal nurseries, too. With the demand for fast-growing superior stock, nurserymen established a fundamental principle for success: The better adapted a seedling is to its planting site, the better it will grow. They developed a system for collecting cones and carefully cataloguing them by species, elevation, and climate. Scientists call this precise identification the seed zone.

When the timber production bust hit, it left nurseries and agency officials fighting for the future of their century-old system. They found its raison d’être in wildfire—millions of acres of wildfire. Starting in 2000, the size of runaway fires on national forests exploded throughout the West. In the last 10 years, the burned acreage more than doubled the average acreage of the previous four decades. Fire has blackened nearly seven million acres every year since 2000.

 

FROM FIRE TO FOREST

On a clear spring morning, I drive through the rolling foothills of California’s central Sierra Nevada, climbing past sun-dappled vineyards and apple orchards in first bloom to the Forest Service nursery just outside the Gold Rush town of Placerville. Cultivated fields lined with six-inch pine, fir, and cedar seedlings surround a compound of buildings where scientists, silviculturists, and geneticists propagate nearly five million seedlings a year. Bruce Boom is waiting at the office door with a broad grin and a welcoming handshake. A lanky man with graying hair, Boom is the Placerville nursery manager.

Bruce Boom, nursery manager in Placerville, CA. (Credit: Jane Braxton Little)

The sprawling operation on 157 acres of fertile clay loam was established in 1957 as part of the Forest Service response to the post-war demand for timber. In the timber harvest heyday of the 1980s, annual production here peaked at over 16 million seedlings. Boom leads me across a paved area bigger than a basketball court where the nursery starts the process of restoring devastated forests. Every autumn, cones from as many as 17 different tree species arrive in thousands of bushel bags tagged by seed zone.

The Sierra sun gets the first crack at opening them as they lie in trays grouped by origin. The sunsoaked cones are then hauled into a cavernous open-air warehouse, loaded into a hopper, and fed into a tumbler that shimmies and shakes the seeds apart from their woody protectors and sorts them by size. Next, the seeds are X-rayed to determine which ones are viable. Then they go into deep freeze in a warehouse-size locker that stores them at zero degrees Fahrenheit.

After a wildland fire, Boom will get an order for a specific number of seedlings of a specific species. That launches the germination process. Nurseries across the country have traditionally grown bare-root seedlings, but today they are responding to an increased demand for seedlings grown and shipped in containers, says Maldonado, head of the Forest Service nursery system. Some seeds are sown directly in the field, others in Styrofoam tubes in greenhouses, where overhead heaters and fans regulate the temperature.

Neither the shift from clearcuts to post-fire restoration, nor the adjustment from bare-root to container stock, has affected the meticulous system of cataloging seeds and seedlings according to the zones where the cones originated. What has changed is the diversity of seeds. The demand today is for a variety of plants that might have astounded a previous generation of nursery managers.

Take the Coulter pine. A native of the coastal mountains of southern California, its spiny cones are the largest of any conifer and can weigh as much as 10 pounds, earning them the nickname “widow makers.” Last year, when the Station Fire roared through the hills near Los Angeles, it devastated the native Coulter pines, burning them so intensely that the flames destroyed the cones despite their evolved capacity to open with the heat of fire. After the burn, workers at the Placerville Nursery removed some of the seeds they had stored in the freezer and began raising them for planting in 2011 on the hillsides charred by the fire.

“If we hadn’t had them in the seed bank, we might have lost this species in some of its natural niches,” said Mike Landram, Forest Service silviculturist for the California region.

 

A BOTANICAL ARK

These nurseries grow thousands of seedlings to keep any number of native tree species at a healthy population. (Credit: USFS Region 5)

Wildfires are not the only natural events that damage national forests and grasslands. Maldonado ticks off a long list: hurricanes, tornados, insect infestation, floods. Restoring these areas is also part of the agency’s new mission, he says. Longleaf pine seedlings harvested from national forests helped regenerate lands in Mississippi after Katrina. Several hundred acres were replanted with Forest Service seedlings in Wisconsin after a devastating tornado. Seedlings sprouted in Forest Service facilities are growing native grasses to plant along highways. The nurseries are providing willows and wetland species to restore eroded stream banks, and shrubs and trees to reclaim mine sites. Silviculturists are adapting the storage and classification protocols they developed for commercial conifers to these new plants.

The diversification has expanded the mission of the National Seed Laboratory in Georgia. Opened in 1952 at the beginning of the timber production boom, the lab’s initial priority was to make sure tree seeds had the ability to regenerate. Scientists developed methods for testing that became established protocols, now widely adopted by federal and private nurseries in this country and abroad. Seed certification remains the Forest Service lab’s focus, says Bob Karrfalt, its director, but the seed types have expanded dramatically. Formerly called the National Tree Seed Laboratory, the 16,000-square-foot Forest Service facility with seven employees has been dealing with any and all native plant species since 2005.

“We have so many more plants on our palette now, all for restoration,” Karrfalt says. “We want to ensure that every restoration project gets a good start with viable seeds.”

One of the lab’s newest challenges is testing seed stock to restore the tallgrass prairies native to central North America. Indiangrass, big bluestem, and switchgrass ecosystems, which once waved six-foot tassels toward the sky, have been devastated by agriculture. Restoration at Midewin National Tallgrass Prairie in Illinois uses seeds certified at the Forest Service laboratory for each specific planting site.

The lab is also playing a crucial role in restoring longleaf pine forests, which once occupied over 90 million acres from Virginia, south to Florida, and west to Texas. Agriculture, industrial timber plantations, and fire suppression have reduced these fire adapted ecosystems to less than three million acres. Today the laboratory in Georgia is testing the genetic identity of seeds from species that include bunchgrass and wiregrass as well as longleaf pines themselves. The goal is to ensure that the seedlings eventually planted are adapted to the site to help restore one of the most diverse ecosystems on the planet, Karrfalt says.

The increase in plant diversity has not caused the Forest Service lab to shun trees, its original focus. It has identified four species hard-hit by insect infestation for particular conservation efforts: ash, hemlock, butternut, and five-needle pines. The success of these programs and reforestation projects worldwide depends on high-quality seedlings, says Karrfalt. “And that’s our job.”

The National Seed Laboratory and the network of Forest Service nurseries are all part of a commitment to restore and retain natural biodiversity for future forests and grasslands, says Maldonado. With wildfires on the increase and climate change affecting where individual plants thrive, it may not be enough to protect all of the natural wonder federal lands now offer. But knowing where each seed originated is a good scientific start, he says. It ensures that natives will be planted where they belong. And having the seeds from an immense variety of native species means that species will not be lost despite the inevitable damage from natural and man-made events.

“We know these offspring will be planted at the right location, with no ecological imbalance,” says Maldonado. “We love and cherish these forests. This is how we take care of them today.”

 — Jane Braxton Little writes from Plumas County, California

 

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This article was published in the Summer 2010 issue of American Forests magazine.