sagebrush steppe

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Highlights from the Western Society of Weed Science Annual Meeting 2023

As soon as I learned that the Western Society of Weed Science‘s annual meeting was going to be held in Boise in 2023, I began making plans to attend. I had attended the annual meeting in 2018 when it was held in Garden Grove, California and had been thinking about it ever since. It’s not every year that a meeting like this comes to your hometown, so it was an opportunity I knew I couldn’t miss. The meeting was combined with the Western Aquatic Plant Managment Society‘s annual meeting, so consider that a bonus.

The first meeting of the week was the general session where introductions are made and various updates are given. There were two keynote addresses as well. One highlight for me was learning about Women of Aquatics, which is a support group for women that work in aquatic sciences. Because this and so many other scientific fields tend to be male dominated, it’s good to see organizations offering support and creating community to help address some of the challenges women face when working in fields where they are underrepresented. Another highlight was Matt Germino‘s talk about fire ecology in the sagebrush steppe. Due to decades of overgrazing and the introduction of a suite of invasive annual grasses (among other factors), fire has become far more common in our region than it once was. The sagebrush steppe is not adapted to frequent fire, which is part of what makes restoration work so difficult. In 2015, a megafire (referred to as the Soda Megafire) occurred in the Owyhee Mountains, burning around 279,000 acres of sagebrush steppe. Restoration efforts after the fire have been well researched, and such efforts continue to this day. Research opportunities like this are helping us improve the way we address this issue in the West, and I hope to spend future posts elaborating further on this topic.

After the general ssession, I attended a few of the talks that were happening in the various breakout sessions. One was about climate change trends in the western U.S. No surprise, temperatures are on the rise, and along with that will come changes in the way we receive our preciptation (which has already been documented). Our region is expected to see more rain and less snow, and rain events are expected to be of shorter duration but with heavier rainfall. Snowpack is expected to continue to decrease, and drought is expected to become more extreme, which ultimately leads to more fire weather days. None of this is great news, but it’s important to understand what we are in for. I also attended a talk about non-target impacts that can arise from certain herbicde treatments used to control bird cherry (Prunus padus) in Alaska, which brought me back to my time attending the Alaska Invasive Species Workshop in Anchorage.

Posters!

The following day, the breakout sessions continued, and dozens of talks were given throughout the day. It’s impossible to attend them all, and unfortunately a few of the talks that I really wanted to hear were cancelled. One interesting talk that I’m glad I got to see was about liquid-applied cellulosic mulches used to replace polyethylene sheet mulches (black plastic) in strawberries and other crops. The results seen so far seem promising, and I’m eager to follow this topic to see where it goes and hopefully even try it out myself one day.

During the meeting, there were also a series of posters on display that summarized research being doing by some of the attendees. I didn’t get a chance to read them all, but a few standouts included posters about using prescriptive grazing to help control tall oatgrass (Arrhenatherum elatius) populations in Colorado, using an electrical current to help manage weeds in blueberry farms, and weed seed predation by ground beetles in diversified wheat production cropping systems. If a poster is about some form of novel or underused method of weed management, I’m definitely going to read it.

bur chervil (Anthriscus caucalis) in downtown Boise

It might seem a little odd for me to be attending meetings like this, especially since I don’t work as a weed scientist or in weed management, and much of what is discussed, namely presentations about all the various herbicide treatments used in rangelands, turfgrass, and large-scale agriculture, don’t concern me (nor do they really interest me). Talks like this are what you would expect to hear at a weed science conference, so despite not being my thing, I appreciate that such talks often include discussions about herbicide resistance and the responsible use of herbicides, climate change, drought and responsible water use, and adaptive management approaches to weed control. I’m not sure when I’ll get a chance to attend this meeting again – it may be another 5 years or more – but whenever the opportunity presents itself, I’ll be there.

Next Up: Botany 2023 is coming to Boise in July. I’ll see you there!

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Meet Erigeron linearis

Erigeron is a genus of herbaceous, flowering plants consisting of between 390 and 460 species and is a member of the aster/sunflower family (Asteraceae). Plants in this genus are annuals, biennials, or perennials and are mainly found in temperate regions around the world. At least 163 species occur in the contiguous United States. Erigeron diversity is particularly high in western states; however, each state is home to at least one Erigeron species.

A common name for plants in this genus is fleabane. This name comes from an outdated belief that the plants can be used to repel or poison fleas, flies, gnats, and other tiny insects, a belief for which there is no evidence. In Ancient Greek, the name Erigeron is said to mean something akin to “old man in the early morning,” likely referring to the appearance of the seed heads which look like little tufts of white hair. Some Erigeron species are also commonly referred to as daisies.

desert yellow fleabane (Erigeron linearis)

One species of Erigeron that I would like you to meet is Erigeron linearis. While most of the plants in this genus have flowers that are white, pink, or various shades of purple, E. linearis is a yellow-flowered species, hence the common name, desert yellow fleabane. Another common name for this plant is narrow leaved fleabane, a reference to its linear leaves. E. linearis is a small plant with a prominent taproot that reaches up to 20 centimeters tall and forms a leafy, rounded mat or cushion of whitish or gray-green, alternately arranged leaves. The white appearance is due to numerous, fine, appressed hairs on the leaves and stems. Flower stalks are produced in abundance in late spring through early summer and are mostly leafless. They reach above the mound of leaves and are each topped with at least one flower head, which nods at first, but then straightens out as the flowers open. Each flower head is about 2 centimeters wide and is typical of plants in the sunflower family, with a cluster of deep yellow disc florets in the center, surrounded by ray florets that are lighter in color. Both disc and ray florets are fertile; however, the disc florets have both “male” (stamens) and “female” (pistils) flower parts, while the ray florets have only “female” parts. The involucre, which sits at the base of the flowers, is egg-shaped or hemispheric and made up of a series of tiny, fuzzy bracts called phyllaries.

the flower head of desert yellow fleabane (Erigeron linearis)

The fruit of Erigeron linearis is called a cypsela, an achene-like fruit that is characteristic of plants in the sunflower family. The fruits are miniscule and topped with a pappus composed of short outer bristles and longer, pale, inner bristles. The two types of pappus bristles (or double pappus) must be the reason for the scientific name this species was originally given in 1834, Diplopappus linearis. While the seeds of more than 80% of flowering plant species found in dryland regions exhibit some form of dormancy, a study published in Plant Biology (2019), found that E. linearis is one of the few species with non-dormant seeds. This means that for those of us interested in growing plants native to the Intermountain West, E. linearis is a pretty easy one to grow and is a great addition to water-wise gardens, pollinator gardens, and rock gardens.

Erigeron linearis seedling

Erigeron linearis is distributed across several western states and into Canada. It is found in northern California, eastern Oregon and Washington, southern British Columbia, across Idaho and east into southern Montana, western Wyoming and northwestern Utah. It is found at low to moderate elevations in open, rocky foothills, grasslands, sagebrush steppe, and juniper woodlands. It prefers well-drained soils and full sun. It is one of many interesting plants found on lithosols (also known as orthents), which are shallow, poorly develop soils consisting of partially weathered rock fragments. In the book Sagebrush Country, Ronald Taylor calls lithosols “the rock gardens of the sagebrush steppe,” and refers to E. linearis and other members of its genus as “some of the more colorful components of the lithosol gardens.” E. linearis is a food source for pronghorn, mule deer, and greater sage-grouse, and the flowers are visited by several species of bees and butterflies. The plant is also a larval host for sagebrush checkerspots.

desert yellow fleabane (Erigeron linearis)

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Documentary: The Sagebrush Sea

Last month I posted a few photos of some of the weeds and wildflowers of the Boise Foothills. In that post I touched briefly on the ecology of the foothills, and a few readers expressed interest in more posts about this topic. It is definitely a topic I would like to explore further, but it is not one that I know a ton about. In fact, despite spending the majority of my life residing in this high desert, sagebrush-dominated ecosystem, it has only been in the past few years that I have really gained an appreciation for it. Perhaps that’s understandable. This landscape, which initially appears drab, lifeless, and boring, is not easy to love at first…until you do a little exploring, at which point you find it teeming with life, loaded with diversity, and worthy of admiration.

That is one of the themes of a new PBS Nature documentary, The Sagebrush Sea, which debuted on PBS in May 2015. The film is an intimate view of what’s really going on in this vast, seemingly empty landscape that many of us simply ignore, passing through on our way to somewhere else. It is an introduction to a fascinating ecosystem, shaped and formed by extreme events and inhabited by plants and animals that have unique adaptations that allow them to survive the harsh conditions of the high desert. Some of these plants and animals can be found nowhere else on earth. For anyone looking to learn more about the ecology of the Boise foothills and/or the larger ecosystem of which they are a part, this is an excellent place to start.

The-Sagebrush-Sea

The sagebrush steppe is a plant community dominated by sagebrush (Artemisia tridentata and its various subspecies) and bunchgrasses. At one point it covered as many as 500,000 square miles of western North America – hence “the sagebrush sea” – but human activities have reduced it to half that size. The plants and animals in this ecosystem have been coevolving together for at least 2 million years. Sagebrush is, as the narrator of the film says, “the anchor of the high desert,” living up to 140 years old and helping to ensure that the desert doesn’t become a dust bowl. Sagebrush also provides food and shelter for a great number of species.

The Sagebrush Sea was produced by the The Cornell Lab of Ornithology, so while lots of other plant and animal life get adequate screen time, the birds of the sagebrush steppe dominate the film. One species in particular, the greater sage-grouse, is the star character, driving the film’s narrative and speaking for the protection of this threatened and underappreciated ecosystem.

A view from behind a male greater sage-grouse (Centrocercus urophasianus ) - photo credit: wikimedia commons

A view from behind a male greater sage-grouse (Centrocercus urophasianus ) – photo credit: wikimedia commons

Sage-grouse are endemic to the sagebrush steppes of the intermountain west. They are sensitive to disturbances and are “tied to unbroken expanses of sage.” Their breeding grounds (leks) are large patches of open ground, but when they aren’t breeding (which is the majority of the year) they are taking refuge in the sagebrush and grasses. The females make nests below sagebrush, where they blend right in, camouflaged from predators. Sage-grouse consume various plants and insects throughout the year, but their diet consists mainly of the evergreen leaves of sagebrush. Just 200 years ago there were up to 16 million sage-grouse in the sagebrush sea, today that number has been reduced to around 200,000. Due to such a steep decline, they may soon be added to the endangered species list.

Because sage-grouse are so reliant on healthy, intact, widespread sections of sagebrush-steppe, they are considered an umbrella species. Taking measures to protect them will simultaneously spare and even improve the lives of numerous other species with similar requirements. To begin with, there are a handful of other bird species that nest nowhere else except in sagebrush, specificallly the sagebrush sparrow, the sage thrasher, and the brewer’s sparrow. Other animals feed on sagebrush and rely on it to make it through the winter, such as pronghorn and mule deer. Sagebrush is also considered a nurse plant, providing shade and moisture for grass and forb seedlings growing below it.

The sagebrush steppe is threatened by the usual cast of characters: habitat fragmentation, urban and agricultural development, invasive species, climate change, etc.  Some specific activities like cattle ranching and oil and gas drilling also come into play. While The Sagebrush Sea briefly introduces some of the major threats to this ecosystem, it does not dwell on any single issue or point fingers in any one particular direction. For one, it is hard to place blame when there are so many factors involved; but more importantly, the filmmakers wanted the film to be accessible to everyone in order to foster a greater appreciation for the sagebrush sea and a consequent desire to protect it. The debates regarding this part of the world are heated enough, and those directly involved are already well aware of the issues.

This is a beautiful film. The images it captures are captivating and at times breathtaking. Apart from the sage-grouse, various animal families are introduced throughout, each one stealing your heart. My only complaint is that, at only 53 minutes, the film is too short. Luckily, the world they depicted is right outside my door, and I am now even more inspired to explore it.

To learn more about sage-grouse conservation, visit Sage Grouse Initiative.