fire ecology

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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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Invasive Species vs. The Global Economy

As humans have spread across the globe, other species have followed. The domestication of animals and the advent of agriculture helped speed up this process, but species have been traveling around with humans long before that. Presently, our ability to move species from one corner of the globe to another is unprecedented. As more countries join the global economy, the risk of outsider species establishing themselves in uncharted territory increases. Species introductions via globalization are not likely to decrease, and so the question must be asked: Are we, as a global community, equipped to address this?

A review published in Nature Communications in August 2016 warns that “most countries have limited capacity to act against invasions.” The authors come to this conclusion after analyzing available data about invasive species across the globe and developing a “global, spatial forecast for emerging invasions throughout the twenty-first century.” National responses to invasive species were assessed based on reports to the Convention on Biological Diversity (CBD).

As part of the 2011-2020 CBD Strategic Plan for Biodiversity, nations or states that are parties of the CBD agreed to work towards a series of goals called Aichi Biodiversity Targets. Target 9 addresses invasive species: “By 2020, invasive alien species and pathways are identified and prioritized, priority species are controlled or eradicated and measures are in place to manage pathways to prevent their introduction and establishment.” The authors of the review found that, while most countries have made progress on identifying and prioritizing some of the most prominent and threatening invasive species, “current management practices only target a handful” and “prevention of introduction and establishment lags far behind progress towards the reactive CBD goals.”

Biological invasions are expected to remain high across the globe; however, regions with a high Human Development Index (HDI) face different threats compared to regions with a low HDI. Due to increasing levels of international trade, high-HDI regions will continue to be threatened by introductions via pet and plant imports. Climate change and the coinciding biome shifts and changes in fire frequency are expected to aid in the establishment and perpetuation of invasive species in these regions.

Low-HDI regions have historically been less threatened by invasive species compared to high-HDI regions. As these regions join the global economy, they risk experiencing a much higher level of species introductions. Many of the planet’s biodiversity hotspots are found in low-HDI regions, making these hotspots more vulnerable to invasions as the potential for introductions increases. The authors found that the threat of introductions is at its highest in regions where “high levels of passenger air travel overlap with agriculture conversion.” Low-HDI regions are more limited in their capacity to respond to invasions compared to high-HDI regions and are more vulnerable to food shortages when invasive species disrupt agriculture.

“High risk in low-HDI countries could arise from coincidence between intensifying agriculture sectors and high levels of passenger air travel that is likely to transport arthropod pests. … Low-HDI countries could prioritize screening of passenger baggage for live plants, fruits or vegetables, which could host crop pests and pathogens.” – Early, et al. (2016) – photo credit: wikimedia commons

The authors state: “The intensities and global patterns of introduction and disturbance are changing more rapidly today than at any time during human history.” Introductions are not projected to slow in high-HDI regions, and low-HDI regions will be increasingly threatened as species already well established in high-HDI regions expand their reach. This is grim news, but it also presents an opportunity. Through cooperation and data sharing, our understanding of invasive species can greatly increase, and regions with greater access to resources can share such things with less fortunate regions. This is the hope of the authors as well: “We urge increased exchange of information and skills between regions with a wealth of invasive alien species experts and low-HDI countries that have less expertise.”

For more information about this review, go here. For more information about global trade in the modern era, check out the new podcast Containers.

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Weeds and Wildflowers of the Boise Foothills: June 2015

Boise, Idaho is a beautiful city for many reasons. One feature that makes it particularly attractive are the foothills that flank the city from the southeast to the northwest. The foothills are a transition zone to the mountains that lie to the northeast. Large sections of the foothills have been converted to housing, but much of the area remains as wide open space. There are around 150 miles of trails winding through the foothills that can be accessed from the Boise area. These trails are used frequently by hikers, mountain bikers, dog walkers, bird watchers, trail runners, and horseback riders. The foothills, along with so many other nearby attractions, explains why Boise is such an excellent city for those who love outdoor recreation.

boise foothills trail

I feel embarrassed to say that I had not yet made it into the foothills this year until about a couple weeks ago. I had intended to go for more frequent hikes this year, but life has been in the way. What I was especially curious to see was how the plant life in the foothills changes throughout the year. Because Boise is located in a high desert and receives very little precipitation (especially during the summer months), many of the local wildflowers show themselves in the spring when there is moisture in the soil, after which they wither up and go dormant for the rest of the year.

But there is still lots to see in June. However, it should be noted that when you are hiking in the foothills you must develop an appreciation for weeds, as many of the plants you will see are not native to this area and, in many cases, are in much greater abundance than the plants that are. Species brought in from Europe and Asia have become well established in the Boise Foothills, significantly altering the area’s ecology. One of the major changes has been wildfire frequency. Before weeds like cheatgrass – an annual, shallow-rooted grass imported from Europe – became so prolific in the area, fires were rare, slow moving, and isolated. The continuous, quick burning fuel source provided by dead cheatgrass heightens the risk of more frequent, faster moving, widespread fires, especially in the hot, dry summer months. This threatens plant species that are not adapted to frequent fires.

But this post isn’t about the ecology of the foothills. We can save that for another time. For now, I just wanted to share some of the plants I saw – both native and non-native – on my short walk through a very tiny corner of the Boise Foothills earlier this month.

The trail that I hiked is one of several trails in an area of the Boise Foothills called Hulls Gulch Reserve.

The trail that I hiked is one of several trails in an area of the Boise Foothills called Hulls Gulch Reserve.

 

Bachelor's Buttons (Centaurea cyanus) are native to Europe. They are a common cultivated flower and have escaped from yards into the foothills. They are quite attractive and popular among pollinators. Their flowers and stems are edible so perhaps we should all take to eating them.

Bachelor’s buttons (Centaurea cyanus) are native to Europe. They are a common cultivated flower and have escaped from yards into the foothills. They are quite attractive and popular among pollinators. Their flowers and stems are edible, so perhaps we should all take to eating them.

 

Silverleaf phacelia (Phacelia hastate) - a foothills native that is also a pollinator favorite.

Silverleaf phacelia (Phacelia hastata) – a foothills native and a pollinator favorite.

 

Pale evening primrose (Oenothera pallida) - a foothills native pollinated by nocturnal moths.

Pale evening primrose (Oenothera pallida) – a foothills native pollinated by nocturnal moths.

 

Medusahead (Taeniatherum caput-medusa) is an invasive annual grass from Eurasia. It has an ecological impact similar to cheatgrass (Bromus tectorum).

Medusahead (Taeniatherum caput-medusae) is an invasive annual grass from Eurasia. It has an ecological impact similar to cheatgrass (Bromus tectorum).

 

The fruits of nineleaf biscuitroot (Lomatium triternatum), a spring flowering plant in the carrot family (Apiaceae).

The fruits of nineleaf biscuitroot (Lomatium triternatum), a native spring wildflower in the carrot family (Apiaceae).

 

Fruits forming on antelope bitterbrush (Purshia tridentata), one of several shrubs native to the Boise Foothills.

Fruits forming on antelope bitterbrush (Purshia tridentata), one of several shrubs native to the Boise Foothills.

 

Rubber rabbitbrush (Ericameria nauseosa), a native shrub that flowers in late summer.

Rubber rabbitbrush (Ericameria nauseosa), a native shrub that flowers in late summer.

 

Lichens on the branch of basin big sagebrush (Artemisia tirdentata sbsp. tridentata) another common native shrub.

Lichens on the branches of basin big sagebrush (Artemisia tridentata subsp. tridentata), another common native shrub.

 

Tall tumblemustard (Sisymbrium altissimum) an introduced species and one of many tumbleweed species in the western states.

Tall tumblemustard (Sisymbrium altissimum) – an introduced species and one of many tumbleweed species in the western states.

 

Little spider atop the flowers of western yarrow (Achilea millefolium), a foothills native.

A little spider atop flowers of western yarrow (Achilea millefolium var. occidentalis), a foothills native.

Learn more about the Boise Foothills here and here.

Where have you been hiking lately?