Fire Adaptive Plants for Pollinators
Montana Naturalist : Spring/Summer 2018
My first five years in Montana were blissfully free of wildfire. I’d walk outside, gaze up at Lone Peak, in the Gallatin Valley, and marvel at its crisp outline against the clear, blue sky. Then, as I drove my car full of belongings to Missoula, in the year 2000, I got my first taste of smoke. Literally. Familiar sights were draped in a ghostly haze, helicopters swooped down to the river for water to fight the fires, and the highway closed behind me as if there was no going back. And, well, there wasn’t.
Over the years, wildfire has become a regular visitor to our region, something many of us understand as a normal natural process exacerbated by human activity—but not something we ever get comfortable with. I can’t say that my own family has adapted, but I know, like many, we try to adjust. Last year, it meant fleeing during the worst part of the worst fire season we’ve had on record in the last 100 years.
But I always wonder about our non-human neighbors who can’t flee: the animals and plants who must adapt or die. And, as a gardener and beekeeper, I am particularly curious about how the increasing instance of wildfires might impact our pollinators and what we can do to help.
It is no secret that pollinators play a critical role in the propagation of countless plant species—including food crops. Seventy-five percent of the world’s flowering plant species depend on pollinators to reproduce and 35 percent of the world’s food crops also depend on them for reproduction. Scientists estimate that one of every three bites of food we eat is a result of the work that pollinators do.
Montana’s native pollinator species include six different species of bumble bees, leafcutter bees, carpenter bees, sunflower bees, metallic green bees (or sweat bees), polyester bees, digger bees, and mason bees. There are also 45 species of lepidoptera (butterflies and moths), seven hummingbird species, wasps, certain beetles, and flies that contribute to pollination in Montana.
We rely on native and non-native pollinators to pollinate nearly 40 agricultural crops in our state. And, while not native, honey bees are responsible for the state’s 10th most valuable crop (ranking us in the top two producers of honey in the nation) and for pollinating countless crops and native plant species across the state. But it’s not just about humans. Other wildlife depends on pollinators as well, because without them, there would be fewer nutritious seeds and berries to consume.
It is also no secret that pollinators face many threats: habitat destruction, loss of forage diversity, increased pests and diseases, as well as pesticides and herbicides that increase their vulnerability or outright kill them.
It can seem like there is a lot of gloom and doom when it comes to wildfires and pollinators, but the good news is: in the short run, fire actually seems to help pollinators. In the wake of wildfires, we get more flowers, which translates to more forage for pollinators.
And the other good news is that nature is a fascinating adapter and gives us a lot to work with. There are numerous plants that are pretty effective at resisting fire and many others that are fantastic at recovering after a fire. Knowing about fire-adaptive, pollinator-friendly forage gives us the opportunity to further support our pollinators, by protecting the plants they need and/or planting more of them.
What does “fire adaptive” mean?
In this context, plants adapt certain traits or methods that help them survive and/or reproduce after a fire. Consider our state tree, the ponderosa pine. If you’ve ever walked up on one of these beauties, you’ve likely been seduced by the sweet vanilla scent of their bark. Maybe you’ve leaned your face in for a deeper sniff only to feel the warmth and think that tree might just be made partly of fire. But you’ve probably also noticed how thick said bark is. This thickness actually helps to insulate the tree from the heat of wildfire.
Other fire-adaptive traits in plants include:
Producing new growth from underground organs, rhizomes, or roots.
Protecting buds with layers of succulent, nonflammable foliage.
Locating buds within the main stem and root, in order to protect them.
Possessing seeds that are only dispersed by fire. (Many pine species, including lodgepole pine, only open their cones after a fire—the term used to describe this type of cone is “serotinous.”)
7 Native, Pollinator-Friendly, Fire-Adaptive Plants
(whoa, that’s a mouthful, or a proboscis full)
It’s likely that you’ve seen many of these species of plants in town or on the trails and their beauty is enough. But now you can admire them for their role in our ecosystem as well, and maybe even plant a few in your own yard or garden.
1) Chokecherry (Prunus virginiana):
Chokecherry is a hearty shrub that blooms in April and May. The notable clusters of creamy flowers turn into deep purple-black berries that make a fabulous jam—even though their astringency produces a choking sensation upon eating them (hence the apt name). Those flowers provide some of the earliest forage of the year for pollinators. And the plant is well adapted to fire. Although it is susceptible to top kill in a fire, surviving root crowns and rhizomes re-sprout quickly, post fire. And, chokecherry seed germination improves with heat, suggesting that the plant benefits from fire.
Known pollinators include:
Honey bees
Flies
Sweat bees
2) Yellow Rabbitbrush (Chrysothamnus nauseosus):
This brushy shrub blooms August through October and thrives in more arid climates. The soft green foliage and dusty yellow flowers provide much forage and full ornamentation for the late season. And, traditionally branches of rabbitbrush were used for smoking hides. While rabbitbrush is also susceptible to top kill in a fire, it sprouts vigorously after a burn, from epicormic buds located just below the surface of the soil. It also reestablishes well through seeds that can be carried for relatively long distances.
Known pollinators include:
Painted lady butterflies
3) Prairie Coneflower (Ratibida columnifera):
A cheerful flower with uplifting posture, prairie coneflower tends to thrive in wide, open, sunny locations. It is not known for high nutritional value, but is certainly palatable to livestock and wildlife. It is well suited for post-burn areas. Again, though susceptible to top burn, when dormant it has good fire tolerance, since it sprouts from the caudex—or intersection of stem and root. It also produces numerous small seeds, which increases its ability to reestablish on burned areas.
Known pollinators include:
Skipper butterflies
Bumble bees
Honey bees
4) Lewis Flax (Linum perenne ssp. lewisii):
These elegant, ethereal blue flowers bob on flexible fibrous stems from May through September. They demonstrate good fire resistance because the leaves and stems stay green with significant moisture content throughout the fire season. These same plants have been cultivated for over 4,000 years in Africa and Eurasia, to produce linen thread from the stems. And they tolerate drought, cold winter, and semi-shaded conditions. They also produce ample seeds, therefore ensuring greater recovery, post fire.
Known pollinators include:
Flies
Mason bees
5) Maximilian Sunflower (Helianthus maximiliani):
A Montana summer is not complete until you see these bright beauties growing in clusters on hills and roadsides. You won’t see them, however, on highly grazed range. They provide much late season forage for pollinators and mammals alike, where they do bloom. They also show strong fire tolerance when dormant, and reproduce with both rhizomes and seeds that allow them to thrive on burned sites.
Known pollinators include:
Honey bees
Bumble bees
Other native bees
Butterflies
6) Blanketflower (Gaillardia aristata):
This yellow and red beauty blooms abundantly July through September and has become a favorite in water-wise gardens across the state because of its ability to thrive in variable conditions and the stability it provides in disturbed areas. The plant has long been known for its medicinal qualities—the Blackfeet used infusions of its roots and leaves to treat their upset stomachs and saddle sores, on horses. It was also one of the species collected by Captain Meriwether Lewis along the Blackfoot River in 1806, and contemporary cancer studies have determined that the plant contains a tumor-killing compound. The plant’s chemistry composition is not considered volatile and it has a high moisture content, so it is believed to have low likelihood of flammability.
Known pollinators include:
Long-horned bee
Fritillary butterfly
Skipper butterfly
7) Smooth Blue Aster (Symphyotrichum laeve):
An autumn favorite, these showy purple flowers with yellow centers provide dense clumps of hearty blooms in August and September. White-tailed deer prefer to graze this plant to other forbs and it provides them with high nutritional value. Of course, it also attracts many pollinators, but is particularly suited to butterflies, as it provides them with forage and shelter. Smooth blue aster is rhizomatous and hence can sprout even after being top-killed by fire. It occurs in areas with frequent fire regimes and is presumed to be fire adapted, though there is little specific information available on it.
Known pollinators include:
Butterflies
Native bees
Long-horned bee
Flies
Want to learn more about these and other fire adaptive plants for pollinators? The U.S. Forest Service and the U.S. Department of Agriculture have ample resources online. You can also talk to your county extension agent to find out the plants best suited for your particular area.
And remember: after the fire, comes the bloom.