“Just like peas and carrots” the saying goes. Basic ecology is all about relationships and simply what goes together. Everywhere you look one plant or animal is relying on another organism, and the more you examine a single plant or animal the more you realize it is connected to another, and then another...The very definition of ecology is the study of relations of living things to each other and to their environment. Some educators and students may think of the savannas of Africa or predators and prey in the Arctic when “ecology” comes to mind, but it can be studied in a scene as small as a raised flowerbed in a schoolyard and most certainly during a field experience to an actual prairie, Ozark woodland or glade.
Ecologists refer to these relationships as symbiotic. A symbiotic relationship is where two species live together in an intimate association and one or both species benefit from the relationship. Symbiotic does not always mean a benefit for each species. Where they both benefit we call that mutualism. The second type of symbiotic relationship is where one living organism clearly benefits, but the other seems to experience no
positive or negative effect. We call these types commensal or commensalism. The third is parasitism, where one organism has a benefit and the other is disadvantaged in some way.
An established plot of selected milkweed species and other prairie forbs and grasses, as discussed in part one in the STOM newsletter, will lend itself to an array of studies and be geared for all ages or grade levels. Upper elementary students to high school students often examine such relationships, which go far beyond one species providing food for another. Relationships dealing with transport of seed, protection from sun or wind, watching for mutual predators, and providing suitable conditions so another may live or raise young are just a few examples.
See if you can distinguish these three different symbiotic relationships that could be observed from a STOM Milkweed Connection Learning Station in a schoolyard.
Commensalism, mutualism, or parasitism?
1) A hackberry butterfly lapping the salty sweat on the forearm of an observing student.
2) A tachinid fly laying eggs on a variety of caterpillar species.
3) An American goldfinch dropping the milkweed seed, but
using the fluff from the seed to line its nest.
4) A hover fly (bee mimic) in the center of a yellow crownbeard flower. The flower is in a sense bartering nectar for pollen transport.
Discussions about or observations of symbiotic relationships can truly engage students who are learning about ecology. Studying symbiotic relationships in turn can lead to more life science studies, collection of mathematical data, creative writing, and application of the fine arts.
Recommended books for observing symbiotic relationships: Butterflies and Moths, Peterson First Guides by Opler. ISBN 0-
Milkweed, Monarchs and More: A Field Guide to the Invertebrate Community in the Monarch Patch. By Rea, Oberhauser, and Quinn. ISBN 0-9657472-2-0
Nature Smart: A Family Guide to Nature by Tekiela and Shanberg ISBN 1-885061-08-0
Spiders and Their Kin, a Golden Guide. By Levi and Levi ISBN 1- 58238-156-9
STOM member Jeff Cantrell has been teaching landscaping with native plants and how to utilize the naturescaped schoolyard for core curriculum, youth activities, and attracting wanted wildlife for more than 20 years. Educators with questions or
needing recommendations are welcome to contact Jeff at email@example.com