Posts Tagged Chinese Wisteria

Invasive Exotic Species: The Ongoing Battle

Chinese wisteria strangling a forest edge.

Chinese wisteria strangling a forest edge.

If you’ve read this blog much, you’ve read about my feelings regarding invasive exotic species. These plants/animals/diseases are not native to the region, which means they have no natural predators. They move in, spread aggressively, and permanently alter the composition and health of our native forests.

The problem is world-wide. Ecologists everywhere consider invasive species to be the second biggest threat to the remaining biodiversity on our planet. Only outright habitat destruction due to urbanization poses a greater threat to the health of our ecosystems.

Of the alien plant invaders I hate the most on my five acres of North Carolina piedmont, I think the Most Evil prize must go to Japanese Stiltgrass (Microstegium vimineum). This invading grass has transformed creeks and wetlands throughout my region into big ugly messes, and the wildflowers and ferns that once flourished there are disappearing rapidly.

Winter-killed Microstegium vimineum still manages to overwhelm a native holly along the creek.

Winter-killed Microstegium vimineum still manages to overwhelm a native holly along the creek.

Number Two on my alien invader hate list is Japanese Honeysuckle (Lonicera japonica). Except during the coldest of winters, this evil vine remains green all year. Like Chinese Wisteria, Japanese Honeysuckle spreads from tree to tree in our forests, creating a dense tangle of vegetation that impairs the health of trees and provides access highways for predators of our native birds attempting to nest in the trees.

This tangle of Japanese Honeysuckle among the trees makes it easy for snakes, raccoons, and other predators to raid bird nests.

This tangle of Japanese Honeysuckle among the trees makes it easy for snakes, raccoons, and other predators to raid bird nests.

A lot of folks don’t realize that English Ivy is also invading our native forests. Like Japanese Honeysuckle, English Ivy produces berries beloved by birds. They spread the seeds through our forests, and the evergreen ivy starts its takeover. The weight of these non-native vines on our native trees causes them to be more easily pulled down by strong winds and ice storms. And from a purely aesthetic point of view, vines strangling forests are quite ugly.

A native dogwood being devoured by invading English Ivy.

A native dogwood being devoured by invading English Ivy.

My yard is also plagued by one of the invading species of Elaeagnus. More of a problem in piedmont uplands than floodplains, I’m finding it all over my yard now, thanks to bird-aided seed deposition.

The flowers of Elaeagnus are suffocatingly sweet.

The flowers of Elaeagnus are suffocatingly sweet.

Much scarier to me are invading evergreen privet shrubs on my floodplain. I see near-solid coverage of this shrub in wet woodlands throughout my region. They outcompete every native plant on the forest floor.

I am always on the lookout for invading privet. They pop up everywhere thanks to the birds that love their fruits.

I am always on the lookout for invading privet. They pop up everywhere thanks to the birds that love their fruits.

The newest invader on my “I hate it!” list is Asiatic Hawksbeard (Youngia japonica). This astonishingly aggressive low-growing plant is outcompeting even the crabgrass in my lawn! Wonder Spouse is planning an attack with a propane-powered weeder that burns the aggressors into cinders. I don’t want to think about what happens if that plan doesn’t work.

Terrifyingly invasive Asiatic Hawksbeard

Terrifyingly invasive Asiatic Hawksbeard

Under the “misery loves company” heading, I’m not alone in my battle against invading exotic species. Every government agency charged with protecting our native wild lands and animals is involved in this fight. Anyone caring for a park, farming, growing timber, or any other related activity is battling invasive species perpetually.

If you live in North Carolina and you have the time and discretionary funds to do so, you might want to attend the North Carolina Invasive Plant Council’s (NCICP) upcoming meeting on Feb. 11-12. They hold the meetings in different parts of the state each year. This year, the meeting is in Asheboro, NC at the NC Zoo. This year’s presentation topics include:

  • Invasive plant control in Mecklenburg County parks
  • Monitoring and mapping invasive insects and pathogens
  • Weed bio-control within a regulatory agency
  • Birds and invasive plant dispersal
  • Invasive plant challenges facing the Uwharries
  • Invasive aquatic vegetation and arteriovenous malformation disease
  • Invasive plants knocking at our door
  • Weed identification workshop

A field trip on the second afternoon will feature the NC Zoo’s greenhouse and composting operations, as well as demonstrations of how they handle invasive species on their grounds.

I’ve been to a number of these meetings, and I always learn much. For example, it was at one of these meetings that I learned about the Weed Wrench, still Wonder Spouse’s favorite weed eradication weapon.

I’m planning to attend this year, and I’ll report the highlights here. If you live in another southeastern state, consider contacting and joining that state’s chapter of the Southeast Exotic Pest Plant Council. I checked the links to each state, and it looks like the Alabama, Florida, and North Carolina chapters are the most active, holding annual meetings. If you live in Georgia, Kentucky, Mississippi, or South Carolina, I would encourage you to contact those chapters through the above link and ask them why their site is inactive. I can promise you it is not because they aren’t fighting invasive alien species in those states too.

If we stand any chance at all of preserving healthy native ecosystems in our parks, national forests, not to mention our own back yards, we all need to know as much as we can about invasive alien species. Forget about invaders from outer space. The invaders we need to worry about are already here.

2014 is the Year of the Lepidoptera!

To end on a happier note, I thought I’d let my fellow North Carolinians know that our state park system has decided to highlight our native butterflies and moths this year. All of our NC parks will be offering walks and family-focused events throughout the year that will educate folks about these important insects. To find a list of events near you, go here.

 

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No Foolin’: Purple Plague Ushers in NC Invasive Species Awareness Week

Chinese wisteria strangling its victims

I call the bloom period of the invasive exotic Chinese Wisteria (Wisteria sinensis) the Purple Plague, because the long, grape-like clusters of blooms are purple, and because the bloom period of this invader visually emphasizes its plague-like effect on our southeastern US woodlands.

I’ll concede that the blooms are not ugly, and many folks like their overpoweringly sweet fragrance, although I’m not a fan. It was the aesthetic appeal of this plant that got it here. Many southerners fell in love with it, draping it over arbors, sides of houses, and training it into artfully shaped waterfall-like forms in their front yards.

If Chinese Wisteria stayed where it was planted, I would not object to its existence in southeastern yards and gardens. But it doesn’t, not by a long shot. Actually, shot is a good word here. You see, the seed pods of this vine are long, bean-like structures. On late autumn days when atmospheric conditions are just right, the pods split open with a resounding crack that sends seeds flying explosively in all directions. I’m told by folks who live near heavily invaded forests that when the pods explode, it sounds like rapid gunfire that goes on and on and on, until all the pods have expended their loads.

Why is this vine considered to be a problem? Take a look at this tangled mess growing along a major road about 5 miles from my house:

See how the wisteria vines ramble and climb over everything?

Like the evil invader Japanese Honeysuckle (Lonicera japonica), vines of Chinese Wisteria climb over every plant in the forest, creating impenetrable tangles of vegetation that destroy any chance for a healthy ecosystem in such areas.

Chinese Wisteria vines can grow quite large and woody. The extra biomass, especially when vines are leafed out in summer, can add enough weight to burdened trees to make them much more likely to fall or break during wind events created by thunderstorms and hurricanes. During winter ice storms, when one burdened tree falls, those connected to it by this invasive vine are also likely to fall, pulled down by the vines tangling them together.

As with Japanese Honeysuckle, the sprawling masses of tangled vines, trees, and shrubs, create perfect highways for predators like black snakes, raccoons, and other climbers. In such areas, it is vastly easier for these predators to access and devour eggs and nestlings of many of our native songbirds.

In my opinion, there is never a good reason to deliberately introduce invasive Chinese Wisteria into a landscape. It will not — not ever — remain only where you plant it. It will — without question — escape into nearby woodlands, where it will destroy the integrity, beauty, and health of these small forests that are essential to native wildlife and plants.

And there’s a native alternative to this invader: American Wisteria (Wisteria frutescens). It is not as flamboyantly showy as the Chinese invader, but it performs the same functions — covering arbors, for example, just as beautifully with similar flower clusters. Most importantly, our native Wisteria vine does not escape and destroy our forests — reason enough to plant it instead, if you ask me.

I will freely admit that Chinese Wisteria is not the most damaging invasive exotic plant species in my region of the country. But it’s blooming and very visible right now, so I think it serves as perfect symbol for North Carolina’s second annual observance of Invasive Species Awareness Week, which runs from April 1-7 this year. Many conservation-related organizations plan activities during this week that highlight this issue. The site links you to a calendar of events occurring throughout the state this week.

Many botanists and ecologists believe that invasive species represent one of the top two threats to our native ecosystems. The other threat is habitat destruction due to land clearing. These two issues are related. As more land is cleared, smaller tracts of native forest remain. These smaller tracts are much more easily overtaken and destroyed by exotic invasive species.

If you live and garden in North Carolina, I ask that you take a few moments to visit this link to the Web site of the North Carolina Exotic Pest Plant Council to learn more about invasive species in our state.

If you live in a different state in the southeastern United States, visit this link to the Southeast Exotic Pest Plant Council. The home page includes links to all the member state organizations, so you can find out what they’re doing about invaders in your state.

As a life-long gardener in the Piedmont region of North Carolina, I can personally attest to the transformation of my native woodlands by invasive exotic plants. When I was child roaming Piedmont woodlands in the 1960s, Japanese Honeysuckle was not strangling the trees. Autumn Olive (Elaeagnus umbellata) and Japanese Stiltgrass didn’t overwhelm my beautiful woodlands until a decade or two ago. Same for Chinese Privet (Ligustrum sinense).  The invaders are coming faster now and establishing themselves much more quickly.

Anyone who cares about the long-term health of our native ecosystems should be deeply worried. I know I am. Please educate yourself about these invaders, learn about the many lovely native plant alternatives to the dangerous species.

Much good information is out there. Besides the Southeast Exotic Pest Plant Council site, try the information-packed Web site of the North Carolina Botanical Garden. Here’s a link to their list of exotic invasive plants to avoid. And here’s a link to the page where they offer suggestions for native plant alternatives.

With just a bit of effort, your garden and yard can become part of the solution to this growing problem. Please consider joining me in this battle against alien invaders. Together we can fight the Purple Plague, and restore a healthy balance to our native landscapes.

A typical roadside shot within a few miles of my house

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