The Placerville Nursery and National Forest Genetic Electrophoresis Laboratory

by Steve Tyson, California Native Plant Society

Anyone who has driven Highway 50 toward Kyburz, or turned onto the road to Ice House and climbed the hill to Peavine Ridge, has had at least a fleeting look at the results of a major fire. More than a decade after the Cleveland burn a casual visitor might only see” exposed hillsides with scattered burned snags and some low green growth” possibly dismissed as the very “brush” that could be a detriment to a healthy forest.

Slowing down to take a closer look, one might see that many of the plants (remember that shrubs and trees are plants too!) are in fact native shrubs, growing as they should to help the area recover: Manzanitas and elderberries are well represented, providing habitat for birds and small mammals, as well as food when abundant fruits and berries ripen. Native grasses should be sending up seed stalks to wave gracefully in the breeze, and certainly a number of wildflowers will be found scattered throughout the openings between the islands of woody shrubs. So in fact there is a considerable amount of forest growth to be found when one takes the time to look. And just look how many small pine trees there are.

But these numerous trees didn’t just happen to sprout at the same magic moment sometime after the fire. They were transplanted to the hillside by crews bringing them from the nursery. The nursery? Yes. One of the great “secrets” in our county is the existence of the USFS Placerville Nursery, deceptively located in Camino just a few miles off Highway 50. What could be easily missed by casual visitors is an eye-opening surprise once discovered: acres and acres of tree seedlings; in fact, up to 15 million seedlings in a busy year, specially grown to reforest California’s national forests. Let’s take a look at how this works.

First, you should dismiss the notion that the best thing to do after a fire (or any other major destructive force) is to simply hurry in and replant trees. While that may be a great idea in theory, it’s a bad idea if the job is to be done correctly. Why? Because when it’s necessary to replant trees, the best plan is to put back trees that match what was removed, and not just pine trees replacing pine trees. There’s more to it.

The Forest Service has spent many years researching trees at facilities in Camino, addressing two main concerns: reforestation should be done with seedlings matched to the specific climate and elevation, and the seedlings should insure genetic diversity. To this end, the Camino nursery houses the National Forest Genetic Electrophoresis Laboratory, or NFGEL.

Electrophoresis? Suffice to say, bits and pieces of tree material are crushed and treated to produce a solution, then a paper strip is soaked in the solution and inserted into a small slice of a starchy gel. Once this obviously decorative bit of science is constructed, the lab assistant Igor is asked to turn on the electricity. Current zaps through the gel and as a result, enzymes are sent scooting away from the tree juice sample and into the gel. When the smoke clears, the gel is sliced and put into yet another chemical bath, and Bingo!, the genetic code of the sample is revealed; every enzyme has produced a colored mark, and those marks make up a signature “band”. It should be no surprise that trees with different genetics produce different banding.

OK, so now we see how to prove that similar trees are in fact not related, we have only one more big question: can tree X grow in location Y? We’re happy to report that the nursery has been working on that one too. Every autumn, seeds are collected from state-wide forest locations, taken from special trees selected for the best characteristics of growth, disease resistance, and other desirable traits. Cones and some branch tips are gathered from these selected trees and brought to the nursery for processing. The branch tips are grafted onto same- species root stock to produce genetic copies of the parent tree; some of those trees will be kept in clone banks, others placed in a seed orchard where they continue to grow to provide more seed stock; cones are spread out in trays, dried, and the seeds extracted and marked, then put into storage in a huge warehouse where the temperature is kept at near-zero. [Note: if you think the smell of pine is wonderful in the summer, visit the cold room in July to experience the refreshing cold combined with the intense fragrance of the seeds! What a treat.]


Storage Tubes

Tubes hold seedlings for storage at the Placerville Nursery

Fact: The Placerville Nursery cold storage room, the only Forest Service seed bank in the state, holds 70,000 pounds of seeds representing every national forest in California.

Now you can see why it can take a little time to get back to a burned area and replant. When there comes a reason to reforest an area, an order is placed for seedlings. At the nursery, when springtime soil is warmed and ready, appropriate seeds are taken from storage and planted to start seedlings, which are managed and watched and let to grow in the ground until the end of autumn. In winter, seedlings are lifted from the fields, moved through an inspection, and then only the best of the bunch are put into storage to wait for spring again, when they will be taken to the reforestation area and planted all over the hillsides. The visitor who parks and walks into the burned areas near Ice House to have a good look around will find that thousands of Ponderosa have reached about the four foot size by now. The forest is returning.

The USFS Placerville Nursery and National Forest Genetic Electrophoresis Laboratory is open all year. It is located at 2375 Fruitridge Road, Camino, CA 95709.

Interested in a tour? If so, call 530-622-9600 between 8:00 a.m. and 4:30 p.m. Monday through Friday.