Invasive Species

Teaching About Invasive Species Used by permission, Tim Grant, author & publisher
Teaching About Invasive Species Used by permission, Tim Grant, author & publisher
Exotic invasive species. “Exotic”, sounds rather alluring, but “invasive” implies something completely different and undesirable.

Basically, we are referring to any species that is not native to that ecosystem, it can survive and reproduce there, and by its introduction can cause harm to the environment, the economy, wildlife, and human health. And this doesn’t mean just plants. There are also invasive animals and even microorganisms that can disrupt the balance that maintains natural ecosystems.

They usually have some means of dominance over native species, such as superior reproduction or faster growth success. They may also have unique forms of defense against native predators. Being newly introduced to an area, they may not even have any competition from similar species, or natural predators may not exist in their new area at all. Their advantages can outcompete native species at alarming rates and result in a reduction, or elimination, of biodiversity in huge areas. And research has proven that having a diversity of native life forms improves the health of ecosystems.

Organizations dealing with agriculture, forestry, fisheries, wildlife and waterways estimate that the annual costs to try to control invasive species in our country exceeds $120 billion dollars. And, whether you are a supporter of the Endangered Species Act or not, a quote from the U.S. Fish & Wildlife Service states “More than 400 of the over 1,300 species currently protected under the Endangered Species Act,…..are considered to be at risk at least partly due to displacement by, competition with, and predation by invasive species.”

In Utah, there are 596 invasive plant species, 28 invasive insects, and a few mammals too. I’ll simply mention a few and why they are so problematic: In the water we are plagued with Quagga and Zebra Mussels, Carp , and plants like Purple Loosestrife. One adult Zebra Mussel can produce one million larvae that mature in one year.

Africanized Honeybees have been sneaking into our State, and they can be very aggressive.
Some of the more common invasive plants include: Russian Olive,
Field bindweed, Dyer’s Woad, Russian and Canada thistle, Stinging Nettle, Tamarisk, …..even Kentucky Bluegrass is on the list. The yellow Dyer’s Woad plant that covers many of our hillside grazing lands, is prolific and may produce 10,000 seeds per plant

The European Starling and English House Sparrow are two birds that don’t belong here, but have been extremely successful by inhabiting all 50 States and occupy nesting sites and deplete food sources of our native American songbirds.

Mammals include the Red Fox, Muskrat, White-tailed Deer (which might excite some hunters), and the adorable Raccoon which may be one of the best examples of the problems invasive species can cause. Raccoons can damage homes, fruit trees, and gardens, kill chickens, cats, migratory birds, pheasants, ducks, quail and grouse. They can also spread disease to other mammals as they eat out of garbage cans, carry fleas, ticks, lice, distemper, mange, and blood tests have shown that 80% of them have been exposed to rabies as indicated by the presence of a rabies titer.

For more information, search online for the topic of interest, plus Utah State University. Or get the book “Teaching About Invasive Species” edited by Tim Grant.

This is Ron Hellstern, and I am Wild About Utah.
 
Credits:

Images: Courtesy & Copyright Tim Grant, GreenTeacher.com
Text: Ron Hellstern, Cache Valley Wildlife Association

Additional Reading

Leavitt, Shauna, The Invasive Phragmites, https://wildaboututah.org/invasive-phragmites/

The Invasive Phragmites

Invasive Phragmites: Great Salt Lake Phragmites Courtesy & Copyright Karin Kettenring
Great Salt Lake Phragmites
Courtesy & Copyright Karin Kettenring
Those unfamiliar with the history of the Utah’s wetlands may see Phragmites and say, “What a beautiful, elegant plant! It looks so graceful blowing along the shore.”

However, the plant’s attractiveness and ability to absorb pollutants may not compensate for its negative impacts.

Phragmites is an invasive perennial grass that now thrives in much of the wetlands around the Great Salt Lake and other marshes in northern Utah. It grows in dense clusters and normally reaches 5 to 10 feet in height. If the conditions are right it can reach 15 feet.

The patches of grass are so dense that wetland managers are called out each year to rescue duck hunters – who are lost in the Phragmites.

Karin Kettenring, associate professor of wetland ecology in the Department of Watershed Sciences at USU and her research team have been studying Utah Phragmites for the past decade.

Kettenring explains why Phragmites is a concern, “We fear it is fundamentally changing the habitat of Great Salt Lake wetlands which are renowned for being a home for migratory birds including waterfowl and shore birds.”

The exotic grass most likely started in the Great Salt Lake wetlands after the flooding of 1983. The flood washed out the marshes. When the water levels receded, the salty water had destroyed all the native vegetation in the wetlands. Phragmites then moved in. By 2011, the exotic grass had spread over 24,000 acres.

Mowing Phragmites Courtesy & Copyright Karin Kettenring
Mowing Phragmites
Courtesy & Copyright Karin Kettenring
Scientists believe humans inadvertently brought Phragmites to Utah, since birds don’t migrate East and West, and the birds usually don’t eat the seeds. Someone’s boat may have transported the seeds into Utah. They sat dormant in the soil until the conditions were perfect, then the spread of Phragmites began.

Today an average small patch of Phragmites, about 20 feet square, can spread a couple yards a year just from the stems it sends out above and below the ground. However, research has shown it’s not the stems that cause the most reproduction – but the seeds.

Karin_Kettenring-in-the-Great-Salt-Lake-Wetlands Courtesy & Copyright Karin Kettenring
Karin_Kettenring-in-the-Great-Salt-Lake-Wetlands
Courtesy & Copyright Karin Kettenring
Karen Mock, associate professor in the Department of Wildland Resources and a long-term collaborator on this project helped Kettenring with the genetic work.

They tested the genetics of a lot of Phragmites pulled from the same patches and found many different genotypes – proving the plants came from different seeds, not the stems of neighboring plants.

With these results, Kettenring’s lab discovered the best way to control the invasive grass is to first control the seed production by mowing the grass mid-summer to keep it from spreading. Then in the fall spraying the area with herbicide three years in a row. An herbicide approved for use in wetlands can be used – such as Rodeo.

If the Phragmites has been there only a few years then the seeds of the native vegetation will still be in the soil, and they’ll come back on their own.

However, if the Phragmites has been there for a long time then re-seeding of native plants will be necessary.

To determine the best way to re-seed wetlands, Kettenring partnered with Utah Division of Wildlife Resources, Utah Division of Forestry, Fire & State Lands and David England – one of Kettenring’s past graduate students. England has spent extensive time in the lab determining how to help seeds germinate.

Emily Martin, Kettenring’s current graduate student will also help with the UDWR reseeding as she searches for techniques to make seeding more effective.

Ultimately their goal is to restore native plant communities to keep Phragmites from coming back and restore habitat for important migratory birds.

This is Shauna Leavitt and I’m Wild About Utah.

Credits:
Photos: Courtesy & Copyright Karin Kettenring
Audio: Courtesy and Copyright Kevin Colver
Text: Shauna Leavitt

Sources & Additional Reading

How to control Phragmites
Kettenring, Karin, Rupp, Larry, Whitesides, Ralph, Hazelton, Eric, Phragmites Control at the Urban/Rural Interface, 2014, https://works.bepress.com/karin_kettenring/92/

Extensive readings about Phragmites:
https://works.bepress.com/karin_kettenring/

Video: USU researchers mowing Phragmites in the Great Salt Lake wetlands. The passenger is Chad Cranney a past graduate student of Karin Kettenring’s:
https://bft.usu.edu/rqcq9

*****

Larese-Casanova, Mark, Phragmites-Utah’s Grassy Invader, Wild About Utah, August 23, 2012, https://wildaboututah.org/phragmites-utahs-grassy-invader/

Common Reed, Phragmites australis. National Invasive Species Information Center, USDA National Agricultural Library, https://www.invasivespeciesinfo.gov/aquatics/commonreed.shtml

Phragmites Factsheet, US Fish & Wildlife Service, https://www.fws.gov/GOMCP/pdfs/phragmitesQA_factsheet.pdf

Phragmites Phragmites australis, Aquatic Invasive Species, Utah Division of Wildlife Resources, Sept 17, 2013, https://wildlife.utah.gov/habitat/ans/phragmites.php

Phragmites Phragmites australis, Plants Database, USDA Natural Resources Conservation Service(NRCS), https://plants.usda.gov/core/profile?symbol=phau7