Monday, 11 December 2017

Forest Killing Weed: Japanese knotweed

closeup of Japanese knotweed flower

Japanese knotweed, also called Mexican bamboo grows up to 15 feet tall.

What would you say if somebody told you that a weed could crack the asphalt in you driveway, force its way through the foundation of you house and prevent maple regeneration in your woodland? The weed is called Japanese knotweed and it is here in Wisconsin.

Picture of silver maple floodplain forest community.

Healthy silver maple lowland floodplain forest community with native ferns as ground cover. Courtesy of the Maine Department of Agriculture, Conservation and Forestry.

Researchers in Pennsylvania found that the invasive plant, Japanese knotweed (Fallopia japonica), can grow so thick in river floodplains that it can prevent silver maple seeds from taking root and regenerating the forest canopy.

It appears, however, that poison ivy may be a competitor for Japanese knotweed. And unlike knotweed, poison ivy seems to be much more of a team player. Areas with high density of poison ivy had more diversity than those dominated by knotweed. Not withstanding the problems it causes humans, poison ivy seems to be  better neighbor for stream bank plants.

Japanese knotweed is a serious threat in wet soils, especially in lowlands and along riverbanks. Knotweed is also found along bike paths in Madison and roadways in Iowa County.

Knotweed Control

Getting rid of Japanese knotweed is very tough. It grows up six to ten feet tall on hollow stalks that die back in the winter. Knotweed produces a large amount of seed that sprouts really well. High water and even mower decks can easily spread seed or small pieces of cut stalks; both of which can start an whole new infestation. Knotweed also spreads through underground roots called rhizomes that can grow up to fifteen feet deep and twenty feet horizontally in a single year.

Kill very small patches by covering with black tarps that must be held down in place and cover an area fifteen feet wider than the patch itself to keep the roots from creeping out around the edge. The tarps must be left in place continuously for at least three years. This approach does not work for most situations.

Use a combined approach to attacking your Japanese knotweed problem. Cut down in June when the plants are around knee high. This removes stored nutrients from the roots and weakens the plant. Carefully bag and remove EVERYTHING and burn it completely or take it to a commercial landfill. Every small piece of stem that contains a node (where the leaf and stem meet) can form a completely new plant. NEVER take cuttings to a compost facility or place them on a home compost pile.

Repeat the process of cutting, bagging and removing all stems, leaves, flowers and seeds in late August or the first week of September. Again, burn the cuttings completely or taken them to a commercial landfill.

Three weeks later, spray the plants that have re-sprouted with Glyphosate (commercial products include Roundup) according to the label directions.

Japanese knotweed requires three years or more following the same regime to totally eliminate the problem.

Find More Help

For more information about managing Japanese knotweed, check out the Wisconsin DNR Invasive Species factsheet or the UW Extension bulletin.

August 2017

Sunday, 13 August 2017

Little Things Mean a Lot

A new Ontario study shows that destruction of small wetlands can increase algae blooms in the Great Lakes basin. The Canadian Press notes that while government agencies tend to focus more of their attention on large wetland remediation projects, smaller wetlands actually punch above their weight when it comes to filtering out nutrients from runoff.

Authors, Nandita Basu and Fred Cheng, writes in Water Resources Research, Biogeochemical hotspots: Role of small water bodies ilandscape nutrient processing, “Results suggest that small wetlands play a disproportionately large role in landscape-scale nutrient processing.”

Their conclusions suggest that what you do as an individual landowner makes a real difference. “Thus, given the same loss in wetland area, the nutrient retention potential lost is greater when smaller wetlands are preferentially lost from the landscape. Our study highlights the need for a stronger focus on small lentic systems as major nutrient sinks in the landscape.”

The Wisconsin Wetlands Association publishes My Healthy Wetland a handbook for landowners. They also host workshops and publish a quarterly e-newsletter.

July 2017

Wednesday, 26 July 2017

Good Things Come in Small Packages

Wetlands educator show difference between Reed Canary Grass and native wetland grasses.

According to a new study released by University of Waterloo (Ontario, CA) professor Nandita Basu, small wetlands seem to be more efficient at reducing nutrient loading. His team reviewed 600 studies worldwide of wetlands rivers and reservoirs. They concluded that smaller wetlands are more effective as “nutrient sinks” because they have more soil that filters less water.

These findings are particularly important for Wisconsin because too much nitrogen and phosphorus cause the algae blooms that poison our lakes.

The way you manage runoff from your land affects the land and waters that are downhill. Small wetland restorations high in the watershed make a big difference. Restoration contractors and consultants can help you figure out the best practices to manage nutrient runoff.

Wetland restoration can be complicated. Moving soil and many other activities in wetlands require the right licenses and permits. Look for a professional who is trained in wetland ecology and has a proven track record doing wetland projects. Make sure to ask for and check out their references.

The Wisconsin Wetlands Association is a great first stop to find information about out wetlands. They not only have general information about wetlands, they provide really good resources for private landowners. The Wisconsin DNR has an online Wetland Restoration Handbook that has chapters to walk you through the entire restoration process.

Wisconsin’s wetlands are so much more than cattails. You will be amazed at how easy it is to fall in love with your swamp.

2016

March 2016

Saturday, 26 March 2016

Opening Day

Sunday was the first day of burn season. Okay, it was the first day of burn season for me. The truth is my fellow burn buddies in The Prairie Enthusiasts started without me on Friday. Worse, because many of them are retired, they will be burning on Monday and Tuesday while I am punching a time clock.

Burn season is that magical time in early spring between winter brush season and fishing season. Throughout the winter, on days when the weather permits, chainsaws, brush saws and loppers reclaim neglected southern Wisconsin shrub-land to a semblance of the prairie and savanna that settlers found when the arrived nearly two hundred years ago. Brush clearing drives away the winter doldrums, but it is fire that makes the magic.

Fire from prescribed burns is needed to keep the invasive shrubs and aggressive trees like boxelder and black locust at bay. Most trees and shrubs do hot tolerate fire. Their bark burns and the sap layers beneath are destroyed, killing the woody plants. Some trees and a very few shrubs tolerate fire. For millennia, bur oaks, white oaks and hickory have used their tough bark to protect them.

Before European settlement, lighting and fires set by Native Americans keep the prairies and savannas of southern Wisconsin clear. Today, that task falls to public land managers, private landowners and volunteer groups like the Pheasants Forever, Quail Society, Prairie Enthusiasts and Nature Conservancy.

We meet up at the barn at noon and within a half hour a dozen hearty soles are at the first burn unit getting our briefing. Weather is perfect, northwest winds 10-15 mph with relative humidity in the mid 40s means the fire will be manageable, even on the steep slope that makes up our first unit.

A pair of sandhill cranes move off the marsh scared by the commotion of a dozen humans even before flames light up the hillside. They are just beginning their nest building and have not begun laying eggs. Enough unburnt spots will remain in the marsh for them to rebuild a nest in time to raise their family.

The burns continue through the afternoon, right up to sunset. We burn two upland hillside units and a third large marsh area, which has six test wells that must be protected from the flames. All goes according to plan, with the final fire line being closed off as the sun set over the ridge.

Most days I keep my Nomex hood pulled up over my cheeks and nose to protect them from the flames. Today, however, it is the chill wind that keeps my face covered, especially as our crew is forced to wait to light off the upwind side of the marsh unit.

With luck, burn season will continue until Mother’s Day weekend and opening day of fishing season. For everything there truly is a season and a time to every purpose. Helping to restore balance to the land is what conservation is all about and looking over that valley ready for its spring rebirth makes me feel blessed.