Fall Color and Seed Dispersal

by Ana Maria Caballero, Nature Education Specialist
October 3, 2016

teachers drop seeds

Fall Color and Seed Dispersal

teachers drop seeds

Teachers drop different seeds to test flight patterns.

Boston Area Educators Investigate Leaf Color and Seed Dispersal

The following comments were heard this past Saturday morning in the Hunnewell Building Lecture Hall:

“A bird with outstretched wings somersaulting through the air.”

“A twirling ballerina.”
“It rotates while it revolves.”
“A fairy fall.”

No, this was not part of some elaborate circus performance. Instead, Boston area educators gathered to experiment with winged seeds, observing and describing their flight patterns when dropped from the height of a tall ladder. Teachers were amazed by the variety of seed shapes, from the curled strip of the Tree of Heaven (Ailanthus altissima), and the curved, fuzzy wing of the paperbark maple (Acer griseum) to the slender, long-legged bract of the linden (Tilia americana.) They were equally surprised by the differences in aerodynamic behavior among these. A simple tray filled with diverse seeds was enough to get teachers excited about the many ways students would generate questions and design experiments in their classrooms. In fact, the Next Generation Science Standards (NGSS) and the 2016 MA Science, Technology and Engineering standards both state that students will engage in eight practices of science, among them, “planning and carrying out investigations,” and “engaging in argument from evidence.” Teachers also recognized that developing vocabulary and engaging in hands-on experiences are critical to successful science learning, and that integrating body movement, poetic thinking, mapping skills, and plain fun is essential in reaching all learning styles.

Clearly, much fun was had during this first class of the Arboretum for Educators professional development series for the 2016-2017 school year.

cutting leaves for experiment

Teachers prepare leaves for chromatography experiment.

The event actually began with instruction about leaf pigments and color change in the leaves of many deciduous trees. Following this explanation, teachers set up a leaf chromatography experiment designed to illustrate the concept. The leaves of the red maple (Acer rubrum), sycamore (Platanus occidentalis), linden (Tilia americana), and two species of viburnum were cut into small pieces and placed into mason jars, mashed with isopropyl rubbing alcohol and set aside in a hot water bath for an hour to extract the pigments. Later, small coffee filter strips were placed inside the jars in order to capture the different pigments that move at different rates up the filter paper. Thus, by analyzing the results, teachers were able to see which pigments were present in their leaves, and once again, engage in science discourse based on evidence.

These activities, using the Arnold Arboretum’s collections, provide Boston area educators from all grade levels and specialties practical ideas for integrating more life science and outdoor education experiences into their teaching. All educators are welcome to participate – our next Arboretum for Educators event is November 5. Although free, registration is required.

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