Watching Grass Grow II
Lehigh Gap Restoration Project
The following article by Dan R. Kunkle was published in the Fall 2003 issue of Wildlife Activist.
With the onset of cooler weather and several heavy frosts in early October, the first season of growth has ended for the grasses on our test plots on the Lehigh Gap Wildlife Refuge restoration area. While the test results are not yet in for the year, by any measure imaginable, the first season of our re-vegetation effort must be considered a huge success.
Seeding began later in spring than we had hoped, as logistical problems with contractors delayed the start of planting until mid-May. Fortunately, cool wet weather in early summer allowed us to continue seeding test plots and other areas into mid-July – about a month longer than expected. The wet weather continued into August, then sunny, hot weather prevailed leading to phenomenal growth of our warm-season grasses.
Warm-season grasses are native to our area. They are perennials that die back above ground each winter and re-grow each spring. Under normal conditions, they take three years to reach full maturity of height and seed production. Little Bluestem normally grows to about 3 feet tall, while Big Bluestem, Indiangrass, Switchgrass, and others can reach heights of 7 to 8 feet at maturity. Usually, flowering and seed production are delayed until at least the second growing season and often until the third year, and grow to only a height of 6 to12 inches the first year.
Most likely because of the excellent growing conditions this year with unusually wet weather, plus the availability of nutrients and lack of competition, our test plot grasses have exceeded all expectations for performance this year. The plantings were successful at least to some degree on every test plot, including our experimental plots that received only seed – no fertilizer, lime or mulch. Many test plots include grasses that have reached 4 feet in height, and at least four species have flowered and produced seeds, including Big Bluestem, Coastal Panicgrass, Switchgrass, and Indiangrass.
Our consultant, John Dickerson of the US Department of Agriculture and an expert on re-vegetating areas with warm season grasses, believes that those seeds produced in the first year will not be viable (we will test them to find out), and that the spectacular growth was highly unusual. He attributes the phenomenal performance mostly to the weather and warns that we should not expect results like this to be repeated next year.
The grasses we’ve chosen for the restoration process are native prairie grasses that are perfectly adapted to the conditions in our restoration area. They thrive in mineral soil that is very poor in nutrients and contains no organic matter, tolerate drought and heat, and manage to grow in the presence of heavy metal contamination. They build soil and pave the way for ecological succession that will some day lead to a deciduous forest community. (See Wildlife Activist #47 for more information on these grasses.)
Until that forest develops, the grasses provide excellent habitat that has become rare in the eastern United States. These grasses provide cover and forage for grasshoppers and a host of insects plus mice, voles, groundhogs, and other small mammals. These species support a suite of predators, including Preying Mantis, Red Fox, Red-tailed Hawk, American Kestrel, and Northern Harrier which have all been sighted recently in the test plot area. In early October, technicians doing cover surveys observed an photographed a rattlesnake in one of the test plots. The presence of these predators indicates that a healthy ecosystem is already developing on the refuge areas that were completely barren last April.
Birds also benefit from the grassland habitat. Mourning Doves, Song and Field Sparrows, and Eastern Bluebirds are seen regularly in the test plot area. The seeds produced by the grasses are relished by many species, including the Wild Turkeys that frequent the area. We hope to attract other grassland nesters such as Bobolinks, Meadowlarks, and Grasshopper Sparrows to the refuge, as well as Northern Harriers and Short-eared Owls.
When you visit the test plot area, you will notice that signs have been installed that list the grass species planted on that plot, along with a list of the soil amendments that were added – various combinations of lime, fertilizer, and different types of mulch. While each plot was a one-acre rectangle, the effects of the heavy rains can be seen in the profusion of grasses growing down slope of most test plots – the result of seed and amendments being washed down hill.
The rain turned out to be a two-edged sword, creating excellent conditions for growth of the grasses, yet causing severe erosion problems. After the grasses have been established over their entire restoration zone, their extensive and deep root systems should stabilize the loose mineral soil and prevent further erosion.
Year One was a resounding success. We thank Viacom and their consulting engineers, Frank and West, Inc. for their outstanding cooperation in our restoration efforts, and the EPA and DEP for giving their approval, support, and advice to the Wildlife Center. We also thank our two primary advisers, John Dickerson and Bill Mineo for their expert suggestions, which have guided our methods. In our next Activist in spring, we will report to you on the technical results of our test plot studies, and lay out our plans for continued re-vegetation of the remainder of the restoration area. Stay tuned, and come out to see the grasses, which continue to provide food and cover for wildlife throughout the winter months.