(Air Potato Removal)
Park Sites: Emerson Point, Robinson Preserve, Riverview Pointe, Rye Wilderness
Grade Level: 4th thru 12th Grades
Subject: Science, Social Studies, Math
Duration: 60 minutes
Materials: Recycled plastic grocery bags 1 per student, heavy duty trash bag, scale & tripod, spud statistics sheet Optional: trowels
Florida Sunshine State Standards: SC.A.1.2.1, SC.A.1.2.3, SC.D.1.3.4, SC.D.2.3.2, SC.F.1.2.2, SC.G.1.2.5, SC.G.2.2.1, SC.G.2.2.3, SC.G.2.3.4, SC.H.1.2.2, SS.B.2.2.3, SS.B.2.2.4, MA.B.4.2.2
Overview: This activity is set up as a competition. Students work in teams to collect the most air potatoes by weight, the biggest, and the smallest. Procedures and boundaries are determined for clarity and safety. Teams of 2-3 students, once established, will collect air potatoes.
Objectives: Students will discover first-hand the effects of exotic invasive plants on Florida ecosystems. Students will participate in scientific data collecting by weighing in their team’s collection of air potatoes. Students will leave with a sense of accomplishment of doing something positive for the environment.
Background: Air potato Dioscorea bulbifera is an exotic (non-native) and highly invasive vine in Florida. Air potato is a member of the yam family Dioscoreaceae, which produces large numbers of aerial tubers, potato-like growths attached to the stems. These air potatoes drop to the ground and grow into new plants. Each vine is covered with heart-shaped leaves and can quickly grow 60-70 feet in length. The length of the vine can become long enough to shade out very tall trees.
In West Africa Dioscorea species are cultivated for their edible underground tubers. There they are an important commodity. In Florida, however, uncultivated forms are bitter and undesirable for eating. The air potato is believed to have been introduced into Florida as an ornamental and food plant around 1905. By the early 1970s it was recognized as a pest plant throughout the State. It is listed as a Category I exotic pest plant by the Florida Exotic Pest Plant Council.http://www.fleppc.org
Category I: Invasive exotics that are altering native plant communities by displacing native species, changing community structures or ecological functions, or hybridizing with natives. This definition does not rely on the economic severity or geographic range of the problem, but on the documented ecological damage caused.
How To Identify Air Potato: Air potato has a winter dormant period when the stems die back to the ground. In the spring stems sprout from underground tubers, quickly grow and spread, covering all vegetation in its path. The vine's stem is herbaceous (not woody) and round. The leaves are heart-shaped (cordate) and can become quite large, up to 8 inches long. The heart-shaped leaves have a distinct vein pattern, which radiates from a single point. The leaves have long stems (petioles) and are alternate on the stem. Air potato flowers are not often seen. The flowers are small, greenish and fragrant; hanging in clusters (panicles and spikes) up to 4 inches long. The fruit is a capsule of seeds. Air potato plants produce “aerial tubers” that are attached closely to the stems where leaves attach to the stem (axil). Typically, every leaf has an air potato at the axil. These air potatoes are brownish gray and somewhat irregular in shape.
Suggested Procedure:
1. Gather students and give background information. Show samples of air potato, the leaves and the vines. Compare to the native Moon Vine, a morning glory which also has heart-shaped leaves. Be sure to make clear boundaries for collecting purposes and safety precautions.
2. Be sure students put all potatoes in their bag. The small tubers should go into their pockets for later judging.
3. Have students form into their designated team before distributing grocery bags and trowels. Student must remain with his or her partner at all times. Do not weigh in if they are not with their partner.
4. Allow students to collect air potatoes. Assist with collecting techniques such as pulling vines from trees and digging in the “duff” or mulch on the ground.
5. Call students for weigh-in, allowing plenty of time before the next activity. For each team record names, air potato weights and teacher.
6. Dispose of all air potatoes in heavy black plastic garbage bags. Leave these in place for Ranger to pick up.
7. Give prizes for each team that gathers:
- The most potatoes by weight
- The largest potato by size
- The smallest potato judged by size
