Infusing Inquiry into Elementary School Science

Teachers from the Norman Public School District used KFFL to conduct an investigation on the ecological impact of the nine-banded armadillo, Dasypus novemcinctus. The teacher/scientists examined armadillo scrapes at the bottom of a hill, along the ridge top and at a mid-slope site. Plant species presence and soil nutrients were examined in sites in which armadillos had dug as well as adjacent sites where they had not dug.

Soil nitrogen was significantly higher in areas where armadillos had dug as compared to areas immediately adjacent to the “scrape” (No Arm) or areas without armadillo scrapes (Random). Armadillos also avoided areas in which Schizachyrium scoparium (Little Bluestem) was growing. Given the estimate of the U.S. population of armadillos is now over 60 million animals, their potential for large ecosystem level impacts is great.

Here’s the information on an experiment that I have running at KFFL currently, with an undergraduate student, Caitlin Flora.

This plot design will examine the interactions of armadillos, Dasypus novemcinctus, the nine-banded armadillo, with grazing by other small mammals or larger-bodied ungulates on grassland structure and function. Armadillos create numerous small pits (~4 cm x 15 cm in area and ~ 3 – 5 cm deep) while searching for grubs or other small insect prey. These pits can be dug in bare soil or in turf grass areas. These small openings create spaces in which seeds can accumulate and can become an open site for annual plants to germinate. If created in a densely vegetated area, the surrounding plants may fill in the opening vegetatively. They also bring subtending soil to the surface and hence may open up areas of higher nutrient content for plant use.

The large square represents an exclosure designed to keep all rodents out of an area. This is surrounded by a fence that is approximately 50 cm high with a mesh size of 1 cm. The fence is buried about 35 cm into the ground and is topped with a “V” of steel flashing to keep animals from climbing into the exclosure. All rodents inside of the area will be live trapped and released outside of the exclosure.

The small squares are 1 m2 plots. C = Control, Cl = clipped (clipped to 10 cm above soil level every 8 weeks), D = dug with 10 armadillo-like pits per plot, Cl + D = clipped and dug. There are 4 replicates of each treatment. Treatments are replicated outside of the exclosure as well for a total of 32 plots. The design of which treatment is assigned to which plot is called a Latin Square Design. The plots are located on a slight hill and therefore there is an environmental gradient within the area. The ensure that no treatment is found exclusively within one portion of the environmental gradient, a Latin Square pattern assigns all treatments to all portions of the gradient. Prior to the initiation of treatments, plant community structure will be measured on all plots. Soil samples will be taken for analysis of total N, NO3-N, total C, pH, soil moisture level and organic matter content. Following the initiation of treatments, these measurements will be repeated 3 times annually, May, September and March. Plots are located at the Kessler Farm Field Laboratory (KFFL) in McClain County, a multidisciplinary field research and educational site.