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Monthly Archives: April 2014

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I wish this plant looked a little less attractive.

It seems to have a lot going for it.

Bush honeysuckle is a nice looking plant: its glossy leaves are some of the first to emerge in the Spring, and hang on well into the Fall. Attractive, scented flowers blossom in June, followed by edible berries that remain on the bushes through the Winter. It can tolerate some shade, and its root system can help to stop erosion. No wonder they were deliberately and thoughtfully introduced to this country!

Sounds good, right?

In fact, of the four types of bush honeysuckle that grow on Beaver Island, two are native. On the surface, they are almost indistinguishable from the two types that we label “invasive.”

So, what’s the difference?

Not all non-native species are “invasive.” My hyacinths are not taking over the yard, no matter how much I encourage it. Many plants – though not part of our native vegetation – are welcome additions to our yards and gardens.

That is not the case when it is an invasive plant.

I just did an internet search of “attributes of invasive plants”, thinking I’d find a concise,  understandable list that I could share. I was humbled and horrified by explanations that were so far over my ability to make sense of them, I couldn’t begin to interpret them. I tried “characteristics of invasive plants” with similar results. If you’d like that information, it’s out there. Meanwhile, let me explain it as I understand it.

Invasive species have an advantage.

Maybe this advantage comes to them because our climate is even more favorable to their growth than their home climate was. Maybe our soil lacks the microbes that would slow their growth or reproduction. Perhaps the animals that might feed on the plant are not available here. Plants that would compete with them for nutrients, light and space do not grow here. This allows them to be a “bully” in our eco-system, taking over land and space so aggressively that our native species are crowded out.

According to the brochure of Top Ten Invasives (which is the source for my list), published by the Beaver Island Association (<www.beaverislandassociation.org>), invasive plants

  • decrease your ability to enjoy hunting, fishing, mushroom collecting, bird watching and other recreational pursuits
  • if left unchecked, will limit many uses of our islands now and for future generations
  • can harm the natural heritage of our wetlands, fields, forests, lakes and rivers

In the case of invasive Bush Honeysuckle, the plants have a “rampant and aggressive” growth pattern that forms dense thickets. They block the sunlight, preventing other plants from growing there. It is believed they also may release a chemical into the soil that is toxic to other plants. Though it was once believed that it would provide a habitat and food source for wildlife, the opposite is true. Wildlife was left more exposed to predators, and the berries produced have no nutritional value to the birds that eat them.

Though very similar to our native honeysuckle, the invasive plants can be distinguished by their flowers. Native honeysuckle have yellow blooms. The invasive strains (Tatarian, from Russia, and Morrow’s, from Japan) have flowers of pink or white. The older stems of the invasive honeysuckle are hollow; all stems are solid in the native plants. They are generally found in sunny areas, and form dense stands about 6′ tall.

Cutting alone will not destroy the plant, as it can regenerate quickly from the roots. Pulling is effective in small stands or with young plants. Digging out older plants, being sure to get the entire root system, is one way to control them.  A glysophate herbicidal solution (Round Up)applied to the plants or cut stems can work to kill the plant. As always when using herbicide, care should be taken to protect surrounding plants, water and wildlife.

When purchasing decorative plants, make sure they are not species that can threaten the natural beauty of our island.

As we’re getting out and about this year, let’s all be aware and keep watch for the invasive plants that threaten our landscape.

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As promised, this is the first installment of our “Top 10 Invasive Species” countdown (David Letterman, eat your heart out!).

I’m starting at the end of the list, with Narrow-Leaf Cattail.

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We all know the cattail plant, I think. Cattails have gone in and out of favor as a decorative accent in flower arrangements, but they’re a fairly common road-side sight.

The narrow-leaf cattail is a plant that did not originate here. Because of that, it has an advantage.

The scientific name is Typha angustifolia, and was first noted in Michigan in 1837.

Like most invasive species, narrow-leaf cattail forms a monoculture that replaces native plants in high quality natural areas. Its roots produce dense mats of rhizomes. Its leave produce a thick litter layer that reduces the opportunity for other plants to establish or survive. This reduces critical food resources for birds, butterflies, and other wild creatures.

Many areas that were once diverse plant and animal habitat are now solid stands of cattails.

Narrow-leaf cattail grows 3′ – 6′ tall. Long (2′ – 5′), narrow and flattened leaves show up in the Spring. Flowers emerge mid-Summer. The male part of the flower is the distinctive velvet brown, cigar-shaped protuberance that we all associate with the cattail. The female part of the flowers emerges above that, on each stem.This is where invasive cattail can be easily distinguished from native (Typha latifolia) cattails. There is a distinct gap on the stem between the male and female flowers, on the invasive narrow-leaf cattail. This gap does not exist on the native plants.

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Each plant can produce up to 250,000 seeds in a single year. The seeds can remain viable for one hundred years! Reproduction is possible not only by seed dispersal, but by the thick, rapidly-spreading lateral rhizomes. To add to the horror, narrow-leaf cattail has been known to hybridize with native cattails, creating a strain that is even more difficult to control. According to the USDA Forest Service,  the habitat for narrow-leaf cattail includes: wetlands; lake shores; river backwaters; roadsides; ditches; disturbed wet areas; bogs; fresh or brackish marshes, lakes and ponds. It can thrive in either nutrient-rich or slightly saline soils.

Pretty intimidating, isn’t it?

Add to that the fact that measures that might wipe out this invasive species could also destroy habitat for many native species (thus paving the way for other invaders), and the challenge we face becomes evident.

The best recommendations set the goal at controlling the spread and density of this plant.

The first step is awareness, then identification. Where water levels can be controlled, flooding (to more than 48″ deep) can be used to inhibit growth or spread. Some waterfowl graze on the young plants. Controlled burns have been used to get rid of thatch, stalks and leaf litter, but does not kill all the rhizomes. Cutting and disposing of seed heads is a good defense.

As with all invasive species, this is an uphill struggle…and the slope is steep. We need all the help we can get!

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It’s easy, when snow covers everything, to put summer’s concerns right out of mind.

My garden hose is somewhere out there, frozen to the ground. The recent rain and subsequent thaw revealed many things left undone when winter came early: leaves to be raked, twigs to be picked up, perennial beds to be cleared. Out of sight, out of mind.

Other concerns are not so easily forgotten.

Phragmites, for instance.

One on-line course I took this winter told of a large stand of invasive Phragmites (thankfully not on our island) that was treated with herbicide. The stand was so dense, it was necessary to use a helicopter to dispense the herbicide. As soon as snow covered the area, a controlled burn was used to get rid of the stalks and seed heads. Early Spring, the debris was bulldozed, gathered and hauled away.

Then, as weather warmed, new Phragmites growth emerged from the newly thawed ground. 

Non-native Phragmites is a pervasive and determined invader.

Some people question whether we are doing everything we can to be rid of it, once and for all.

Others, more familiar with infestations of this plant in areas where it has gained a greater foothold, are amazed at our success.

I can tell you honestly, total eradication is a steep order.

Certainly greater minds than mine have been working on it.

Teams are studying the spread patterns of Phragmites, through seeds, stolons and rhyzomes. They are actually studying the DNA of the plants to determine which are spread asexually (by roots and runners) and sexually (by dispersal of seeds). From their studies we have learned that the plants that have spread through seed dispersal are much hardier, more resistant and aggressive in their growth pattern. Now we know it is best to gather and properly dispose of the seed heads, to prevent their propagation.

Others are looking into biological methods of Phragmites control. Because the plant is not native, it has the advantage of having no enemies. From the very microbes in the soil that might inhibit growth or spread, to insects or birds that might feed off a native plant, invasive Phragmites has no such inhibitors. We humans are standing alone in the plant and animal world, to battle this plant which is harmful to so many others. Scientists are studying ways to change that. With their success, we could create, at least, a more level playing field. Unfortunately, these solutions are still a ways off in the future.

That leaves us where we are now, with the best resources at this time for battling the problem.

And we have restraints.

The herbicide we use is deemed safe for wetlands and shoreline, but caution is necessary. We want to preserve our waterways and the plants and animals that belong there. We have precious and rare species that we take special care with…but every native species is important. Any time a native plant is displaced or eradicated – whether through carelessness, thoughtlessness or ignorance – it paves the way for invasive species to move in and take over.

One of the best defenses against invasive plants is a strong natural native habitat.

The other best defense is vigilance.

Phragmites is a problem of great priority, but we have other invasive species here, too. I received a report this morning that Japanese Knotweed has reared up on Fox Lake. European Swamp Thistle has been noted in the Barney’s Lake area. Garlic mustard threatens the habitat of many of our woodland flowers. I can’t begin to recognize – or even remember – each of these plants…but that is going to change.

I intend to feature one invasive each week on this blog, with photos, so that we all have the information we need to help protect our island.

As the snow melts, and the ground warms, we’ll all be spending more time outside.

Let’s keep watch.