Fall Phenology Inspires Science-Based Learning in Local Landscape
Along with the colorful transitions that the fall landscape undergoes come opportunities to explore a wide variety of scientific topics. Viewing a fall landscape can serve as a catalyst for studies of botany, dendrology, ecology, and natural history, and can help children to deepen their sense of place and their understanding of themselves as existing within – rather than beside – the local landscape.
Studies of the autumn landscape fall into the broad scientific category of phenology, which is the study of the cyclic nature of growth and change in plants and animals – as is generally attributed to the changing in seasons. The phenology of a New England fall involves observations of patterns of death and preparation for hibernation, as annual plants approach the end of their single-season lives and perennials prepare for a season of frozen sleep.
Trees, the tallest and most noticeable of all plants experiencing seasonal change, undergo perhaps the most dramatic of all transformations. With youngsters, a simple activity like leaf collecting can lead to some interesting activities and scientific insights, but explorations of leaf change on a larger scale can lead to much more powerful learning. Adventure into the fall landscape and visit a scenic leaf-peeping vista to view forests from above, and explore the reasons for tree-related seasonal indicators like falling leaves and changing colors.
So why is it that these seasonal indicators even exist in the first place? This is not a chicken-and-egg sort of scenario, as the roots of both falling leaves and changing colors are directly tied to trees’ need to adapt to the slowly changing seasonal climate. Leaves change colors due to the decrease in sunlight that comes with the fall season. Less sunlight prompts trees to produce less chlorophyll, which slowly allows the leaves to reveal the other color-causing pigments present in their cells. An absence of chlorophyll allows for either anthocyanin (red) or carotenoid (yellow, orange, and brown) to show through. Trees have all three pigments in their leaves, but in varying amounts – thus explaining the differences in leaf colors between trees of different species, trees of the same species, and even between leaves from the very same tree!
After trees have slowed their production of chlorophyll, leaves begin to fall to the ground as part of their preparation for winter. Leaves are filled with water-containing cells that, if left attached, would freeze during winter and cause damage to the tree. However, as fall heads into full swing, trees seal off their branches by decreasing their use of the veins connecting leaves to branches. As a result, leaves are shed so as to allow the tree to survive the winter.
Families can see this phenological phenomenon in action during any outdoor adventure during the autumn months, and can even use leaf colors to identify tree species either from close up or afar. Viewing a forested landscape from above in order to identify trees based on leaf color can also lead to learning about tree growth patterns, as certain species of trees grow better in certain locations and in specific ways based on their method of reproduction (aspens growing in groves, for example, versus oaks growing where acorns have fallen).
Families can put arboreal observations to good use by participating in fall citizen science initiative Project BudBurst. While the project’s name implies springtime studies, Project BudBurst aims to support scientists in understanding seasonal phenomena year-round. Encompassing observations made during the months of September and October, Project BudBurst’s fall opportunities can include observations of trees, as well as wildflowers, grasses, herbs, conifers, evergreens, and more.
Fascinating though plants may be, fall phenology isn’t limited to studies of changes in plants – phenological studies are intended to paint a picture of seasonal change that links all changes and events as they happen so as to allow the connections between them to be studied. Another phenological change to tune in to is bird migration, which can be observed and/or monitored (with any amount of closeness) during tree-observation adventures. Using a bird migration chart, families can pay close attention to the approximate dates when specific species either depart their neighborhood, appear for the winter, or make a short stopover on their journey to another locale. Paying close attention to the changes in local animal populations and animal habits can help to illuminate the subtle and daily climate-related seasonal changes taking place.