Native Plants and Fire

Lacamas Prairie Natural Area in Clark County
Lacamas Prairie Natural Area in Clark County is an example of the landscapes where native peoples used fire to control vegetation for food and medicinal plants, craft materials and wildlife. Photo: DNR

It is known that fire can be a major factor in the health of the forest. It also can be a major factor in the composition of the forest. Many of our native plants have adapted to fire, including lodgepole pine which requires fire to melt the wax on cone scales so they open to spread their seeds, and grasses which thrive after fire has killed the competing shrubs and broadleaf plants.

Native people who managed the lands of the Pacific Northwest for thousands of years understood how valuable fire was in maintaining sustainable stands of native plants. They used fire as we might use chemical herbicides. Eventually, growing trees would provide too much shade for the good production of fruit, tubers, grasses and herbs. So the native people would use controlled burns to rejuvenate failing stands of edible, medicinal and spiritual plants.

Typically, the burns would be conducted in late fall or early spring. This was timed to take advantage of the plants’ ability to store nutrients in their root structures during the growing season. It also took advantage of the cool and wet times that helped control the size and heat of the fires. By keeping the fires small and fast moving, the site never got hot enough to hurt the below-ground parts of the desirable plants, but would prune back their tops and kill the unwanted plants. The trees that were encroaching on the huckleberry, camas, fescue and blackberry fields were kept at bay by fire.

The chemicals that were stored in the tops were deposited on the soil surface and then moved into the rooting zone by rains and melting snows. These chemicals such as potassium, phosphorus and micronutrients became the fertilizer that supported new plant growth. So the residue of the fire along with the energy that was stored in the roots would enable the plants to push up new growth the next spring. Fire also exposed the mineral soil by burning the duff and debris, providing an excellent seed bed for native plants.

In Washington the native peoples kept large prairies open for production of food plants, medicinal, craft materials and wildlife. What new arrivals from Europe thought were virgin prairies were in fact large pastures and gardens. This was also true of the vast berry fields in the mountains and the diverse plant system in riparian areas.

As we have controlled fire in all areas of our environment, an unfortunate result in many areas is that we have enabled nonnative plants to push out the native plants that needed fire to thrive. The nonnative plants also are better users of nitrogen runoff from agriculture and homestead lands. In some cases now the invasive plants have become so prolific that they are better able to repopulate burned area than our native plants. The native plants are no longer present in sufficient numbers to produce the seeds and new plants like the introduced plants.

So how do we take advantage of the native plants’ ability to survive fire if they are no longer in the ecosystem in numbers like they were 100 years ago? As a first step, we need to learn what native plants were growing before fire was excluded on land we manage. We can learn a lot from the work being done by restoration ecologists at universities, federal land management agencies, conservation groups and tribal governments. These entities are all looking at how to successfully replant and reseed burned- over areas with the goal of raising the numbers of native plants in the ecosystem. This will help to increase fire resiliency as well as reestablish traditional gathering areas, and create new areas on public natural resource lands. The real end goal is to provide the public with access to sustainable native plant materials.

Many forest landowners have developed a trust relationship with local Native American families who still practice traditional gathering. The landowners share the forest bounty, increasing access to local plants, while the native families teach how to manage areas for special crops.

Other great sources of information on traditional native plant systems are the journals of early explorers and botanists like David Douglas, who kept detailed descriptions of where he found plants and how they were being managed. A final great resource on native plants for Washington state residents is the Washington Native Plant Society and its website, monthly local chapter meetings, and statewide workshops.

Creating native plant gathering sites is just a matter of learning the proper management techniques, acquiring the seeds, cutting or seedlings and making it happen. Consider converting that root rot pocket into a shade garden of native plants. Or take the area under a powerline or over a utility pipeline and create a mini-prairie of native grasses, shrubs, bulbs and berries. A wet area or a frost pocket where trees will not grow can become a field of wild raspberries, currants, blueberries, blackberries and roses.

These areas can be managed sustainably without herbicides, especially if fire can be included as part of the long term rotation. Not only will you be producing native plant foods but you will be providing flowers for the native pollinators and snacks for the native animals. You will be creating perfect wildlife viewing areas across your family forest landscape.

So put on your forest gardening gloves and get started adding native plant garden plots across your family forest landscape.

By Jim Freed, WSU Extension Forester Emeritus