Data from: Evaluation of mowing frequency on right-of-way plant communities in Mississippi

Abstract: Native grasses and native wildflowers are declining, especially
along roadside right-of-ways due to intensive mowing and herbicide
management practices. Roadside right-of-ways undergo regular disturbances
such as mowing, maintenance, and road developments that affect soils,
groundwater, surface hydrology, and vegetation composition. We
investigated species richness and percent coverage within plant
communities along highway right-of-ways to determine if reduced mowing
increased native plant coverage. The study was conducted using 10 research
plots situated along Highway 25 in Oktibbeha and Winston counties,
Mississippi. Each research plots consisted of three different treatments
as follows: one that included greater than four mowings per year, one
mowing only in fall, and one mowing only in fall with a supplemental
native wildflower seeding. Using line transect sampling, we detected 277
plant species, which included native and non-native forbs, legumes,
grasses, rushes, sedges, and woody perennials (vines, shrubs, and trees).
Total percent coverage of native and non-native plants within different
growth form categories did not differ among treatments (F2, 96 = 0.45, P =
0.83). However, coverage differed between uplands and lowlands (F1, 96 =
18.22, P {less than or equal to} 0.001), between years (F1, 96 = 14.54, P
{less than or equal to} 0.001), between fall and spring seasons (F1, 96 =
16.25, P {less than or equal to} 0.001), and interacted between years and
seasons (F1, 96 = 24.08, P {less than or equal to} 0.001) and seasons and
elevations (F1, 96 = 5.00, P {less than or equal to} 0.001). Non-native
agronomic grasses exhibited the greatest coverage ({greater than or equal
to}90%) in all treatments. Percent coverage of each plant growth form was
greatest in lowlands. Our research showed an increase of native grasses
and wildflower species along roadsides with a reduced mowing regimen. We
concluded that the timing and intensity of mowing for the duration of our
study had little effect on the species composition of plant communities.
However, one mowing per year retained agronomic plant coverage for erosion
control and soil stabilization during roadside maintenance. Specific
proactive management implementations can include native plantings,
selective herbicide use to decrease non-native grasses, continual mowing
from roadside edge to 10 meters (m), and only one mowing in late fall, but
with an extension of the boundary to reach beyond 10 m from the roadside
edge to suppress the invasion of woody plants, which could lead to lower
long-term maintenance costs.