A Wooly Experiment

Starting last year, with the aid of US Department of Agriculture Natural Resources Conservation Service (NRCS) funding, we committed to a multi-year effort to contain invasive plants on sanctuary grounds.  This support allowed us to move forward on a the current Best Management Practice (BMP) herbicides.  Committed to what is the BMP a search for an alternative technique that would lessen the amount of herbicide used on our grounds, especially in riparian areas.  We have heard about goats being utilized in controlling other invasive plants throughout many biotas.  In Pennsylvania, "Goats in the Woods" was initiated several years ago at several state parks to lessen undergrowth in forest interiors with success. However, it was not clear if they were effective in targeting a single species such as asian stilt grass. We set out to determine if goats would be an effective alternative to herbicides and weed whacking.

The first thing we needed in preparation for the livestock was a means of keeping the animals from running off and protected from any predators. Portable electric fencing was the best way of achieving this goal. Three rolls of ElectroStop@Plus single spike 164' fence and accessories were provided by Department of Conservation and Natural Resources (DCNR).  This enabled us to build with one fence a 40’ by 40’ paddock.  They could be rolled up, moved, and setup in a matter about 15 minutes. In order to keep them powered for an extended period of time, we used a 100 amp hour AGM deep cycle marine battery that could be brought in and out in the forest without having to worry about spilling any caustic solutions. This battery lasted about 5 days before it needed a charge. When it came time to charge the battery, it was switched out with a 60 amp hour battery, taken out of the woods, and then brought back in after charging over night.

The initial round of goats consisted of 16 goats total, 5 mothers and 11 kids. Getting all 16 of the goats a half-mile into the woods took many helping hands and a huge chunk of the morning. There is no way this could be done every morning, so the goats remained at the site over night. After a day or two, just about every native plant in the enclosed area was eaten, and the stilt grass was just nibbled at. We then expanded the area from 40’ by 40’ to 80’ by 80’. In a last ditch effort we sprayed to the stilt grass with sugar water and the natives with a cayenne pepper solution. This worked for about 15 minutes before they just ate the natives anyway. After a week the goats were sent back.

After some looking into livestock more, we called a local family who were willing to lend us two of their sheep. These sheep again only nibbled at the stilt grass, and were sent back after just a couple of days with no results. It cannot be said that no sheep are effective, but these were used to eating sheep feed rather than grazing for food.

Finally in our last attempt, we brought in 4 goats from St Thomas...Pennsylvania that is, and who were said to eat stilt grass. They were given only a week no matter how successful they were, because we simply ran out of time to use livestock this summer. However, if they were effective they would be brought back next year. They did nibble on the stilt grass and brought a lot of attention to the problem of invasives.

Ultimately, it was decided by Hawk Mountain Managers that goats can be effective in some applications but not an efficient means in what we were trying to accomplish. Trying to herd goats into the middle of the forest is not practical. They do not want to be put in the woods like that and are very reluctant to follow. It only takes a couple of days for the goats to be ready to move on to their next paddock due to eating all non-targeted native vegetation.  But, beyond all that, they eat the native plants along with only nibbling the invasives. So, if the purpose of the project is to be protecting the forest biodiversity, then we concluded that the use of livestock is not the best method for controlling asian stilt grass.

Fire Blasting the Invasives

The majority of our time so far has been spent manually pulling out the barberry, using a rock bar to pry it out or wrapping a sling around the base and using a winch to rip it out. These methods are effective, but are a lot of work and very time consuming. We decided to look for other approaches and came up with torching. 

Torching is used sometimes in place of weed whacking. Since the stems of barberry are pretty thick, we start off by clipping the base of the bush before actually torching. In order to completely kill the bush, the torch must be held on the plant for about 30 seconds or more. We are not 100% certain this method works, so a test grid was set up. That way in a year we can come back to see if torching was effective. Overall I would say torching took about the same amount of time as using a rock bar, and it should not be done on a dry day. However, it was much less strenuous and would be a good manner for getting the isolated bushes that surround the dense thicket of barberry.

Where in the World: Mapping Stiltgrass Communities

Japanese stiltgrass tends to grow in homologous communities, covering large areas and choking out all other vegetation. The problem is especially obvious in sites cleared by humans—chiefly roads, crop fields, and drainage sites.

After we kill the stilgrass in one of these patches, there’s almost no remaining ground cover. These immediate landscape changes are obvious, but we’re really more interested in observing how the areas regrow, to assess whether our work is effective in the long-term. To gauge our baseline, we’ve begun using portable GPS units and GIS software to map areas currently dominated by Japanese stiltgrass. Basically, one of the project members walks the edge of a stiltgrass patch carrying a GPS unit.

The unit tracks the path, which we then import into a GIS program that superimposes the data points over a map of the area. Keeping tabs on annual changes in these borders will allow us to determine both whether we’ve successfully contained stiltgrass in areas where we’re working and whether stiltgrass communities we haven’t reached are continuing to expand.

Asian Stilt Grass!

Microstegium vimineum, commonly referred to as Japanese stilt grass or Chinese packing grass, is part of the Poaceae or grass familly. The stilt grass is traditionally native to Southeast Asia, but was introduce to the United States around 1919. Originally, the stilt grass was used to pack Oriental porcelain, which is how it probably first appeared here. Stilt grass was first introduced into the Tennessee area and can now be found from south New England to the Carolinas and west to Texas and Illinois. 

Stilt grass is an annual plant that sheds hundreds of seeds before dying off in the late fall months. Stilt grass is usually spread by land disturbances, such as, grazing, burning, or logging. The seed can also be carried by moving water, so patches tend to appear in wet areas. Once it settles to an area it can spread quite rapidly. The stilt grass can grow in large patches that will outcompete native plants and block out sunlight to  other understory plants. 

There are a few methods that can be used to manage Asian stilt grass. Pulling the packing grass by hand is a simple and relatively easy way to manage it, but if there is a large area then this could take time and require several years of pulling to exhaust the seed bank. Another way is by weed whacking and mowing the stilt grass. This should be done late in the season to avoid the seeds from setting. Herbicides area also an effective way to manage stilt grass, but will usually kill the native plants with in the area.

Lowering the Bar(berry)

Japanese Barberry (Berberis thunbergii) was originally introduced to the United States as an ornamental plant primarily used in botanical gardens and landscape design. The shrub produces bright-red berries, which birds consume, resulting in widespread seed dispersal. Barberry also spreads through root creepers and—in our experience—tends to grow in dense thickets. Originally introduced in 1875, the shrub can now be found throughout the East and has spread as far west as Montana. For this project we are targeting an area of high-density barberry that has choked out native understory growth, particularly ferns, blueberry, and oak seedlings.

 As of now, our primary method of management has been manual pulling. Although they lack depth, the shrub’s root system is tough and plants that cannot be pulled by hand are ripped out using a winch system.  For a few plants a standard come-a-long could be utilized.  But since we were dealing with an extensive impacted area we needed to find a more efficient system of removal.  That system is comprised of 3/4 ton rope puller with a 1/2" rope and several tow straps  (see below video clip).  This system allowed us to adjust more quickly to hooking into a new shrub after pulling one out.  After a rain the shrubs pulled easier and sometimes by using only a digging bar.  When using the winch system a minimum of two were necessary, but three personnel was ideal.  

 From a worker’s perspective, Japanese Barberry is probably the most frustrating invasive targeted in this project. The stems of the shrub are covered in hundreds of spiny thorns that easily break off into the skin. Also, scientists Jeffery Ward and Scott Williams with the Connecticut Agriculture and Experiment Station have found a positive correlation between Japanese Barberry and ticks carrying Lyme Disease. In the future, we plan on experimenting using livestock grazing and controlled stem burning as methods of barberry management.

The Newest of the Invasives!

Garlic mustard, or Alliaria Petiolata, was first discovered in the US in 1868 in Long Island, New York. It was brought over from Europe to be used in a couple different foods. However the plant has only been on Sanctuary grounds for about 15 years now. 
 

 The impact up here at Hawk Mountain is mainly along the roadside. This invasive can take over undisturbed areas of forest relatively easily. It competes with native plants for light and space. The seeds germinate in early spring, so garlic mustard is the first invasive we managed. Since it is an annual, once the plant dies that season it does not re-sprout.  The aggressive nature of this plant is in the amount of seeds (thousands) each individual can produce which can germinate the following spring. The best approach for us at this time was to hand pull and weed whack prior to the plant producing seeds.

- Lucas

Meet the IPRP Staff for 2014

Project Manager Lucas Wessner

Lucas Wessner just finished his freshman year at Bloomsburg University studying geology. He first got involved with Hawk Mountain as a Conservation Corps member, and is now working on the Invasive Plant Management Project. Luke likes to play soccer, ski, go backpacking, and kayak on weekends.

Project Staff Member Sam Summer

Sam Summer volunteered at Hawk Mountain throughout high school as one of the original members of the Conservation Corps. Now, he's returned as a full-time member of the Invasive Plant Management Project. A rising sophomore, Sam attends the University of Pennsylvania, studying architecture and environmental science. In his free time, he enjoys backpacking, climbing, and drawing.

IPRP Intern Grif Griffith

Grif Griffiths is an up and rising senior at Marshall University in Huntington, WV. He is studying Natural Resources & Recreation Management. Grif is completing an internship here at Hawk Mountain as a requirement for graduation. He will be involved in the Invasive Plant Management project. After school he will like to continue working with the conservation and preservation of natural resources.

Project Staff Member Connor Mertz

Throughout high school, Connor Mertz volunteered at Hawk Mountain Sanctuary as a member of the Hawk Mountain Conservation Corps. He just graduated from Kutztown High School and starting this fall Connor will attend Montana State University to pursue a degree in Sustainable Food and Bioenergy systems.














This is the dedicated staff at this time...but as future posts will tell this is not all inclusive to the who's who working to keep Hawk Mountain Sanctuary's forests filled with our native flora!  

Happy Trails,
Todd Bauman