Grassland Restoration Project - Third Year of Establishment - 2017

Summary

This year marked the third season for the 30-acre grassland restoration project. The most significant change in management was the mowing schedule to control invasive plants. The absence of extensive weed flushes during the summer resulted in a single mowing which took place in early May. Regular inspections and removal of invasive plants continued through out the summer in place of large scale mowing. Two interns were hired for a period of 10 weeks with the major responsibility of locating and removing invasives.

The invasive plants that required frequent monitoring and removal were mugwort and Canada thistle. While not extensive both plants occurred in small patches through out the field. Mile-a-Minute was less problematic in its distribution and ease of removal. Black locust saplings grew to a height of 2 to 3 feet by August and were removed by either cutting the roots at 6 inches below the soil surface or digging out the entire root. A small number of multi- flora rose and porcelainberry plants were found along the southwestern border of the field.

The warm season grasses were dense and abundant through out most of the 30 acres. Big bluestem was most abundant followed by Indiangrass. Little bluestem could be found mainly in the hilly sections of the field that had previously suffered erosion and can be described as rocky and sandy substrate. The Little bluestem in these areas was noticeably less dense and shorter compared to other areas of the field where it occurred. Switchgrass is by far the least abundant warm season grass.

Spring

From mid-April until mid-June approximately eighty volunteer hours were spent raking thatch off the field to encourage the growth of native vegetation. Although this effort was labor intensive it appeared to be successful judging from the resulting growth of Warm Season Grasses over the summer season.

Vegetation Transect Results

Vegetation transects were conducted during June and July. The survey consisted of 3 transect lines with a total of 47 stations. Percent composition was estimated in a meter square quadrant every 50 feet.

Data gathered and analyzed for both transect periods indicates the following:

1. A higher percentage of native vegetation compared with invasive species.
2. Woody vegetation was minimal and consisted primarily of black locust and multiflora rose.
3. The percent composition of all identified invasives in June was 0.74% and in July, 0.84%.

Native vs. Invasive Vegetation

While native vegetation maintains a higher percent composition than invasive forbs and woodies in the restoration site, field observations would argue that the presence of invasives maybe greater than transect data suggests. For example, although no woodies were found within the transect samples or along the transect lines, several multiflora rose were located within the south area of the site. It is likely that additional woody vegetation is scattered within the 30-acre site. In addition, small isolated areas of invasive forbs such as Canada thistle and mugwort exist outside of the transect area. Given these findings yearly monitoring and removal of these plants should be continued.

Summer Environmental interns and volunteers in back of Mugwort pile.

Mugwort growing on field edge alongside Goldenrod.

Invasive Species

Despite the success of warm season grasses in comparison to other vegetation, there remains problematic areas of invasive plants including mugwort (Artemisia vulgaris), Canada thistle (Cirsium arvense), and mile-a-minute (Persicaria perfoliata). These species were difficult to manage and control due to their location within the field, physical characteristics and removal method. Mugwort is thought to be an allelopathic species that colonizes an area through an extensive root system and eliminates native species through its expulsions of chemicals inhibiting native seed germination. Mugwort was most extensive in the southeast section of the restoration field and smaller patches in other locations. Canada thistle, like mugwort, was found throughout the field but was mainly located southwest of the Hickory trees. Moreover, mile-a-minute (MAM), was found primarily east of the hickory trees extending west to east often referred to as the “hickory shadow”. MAM was also found along the northwest border of the field during the month of September. Canada thistle was difficult to remove because of its prickly exterior, as well as its fluffy seed head that was hard to manage under windy conditions.

2017 Plant list in Restoration Site by monthly occurrence.