In much of North America east of the Mississippi River, the rainfall levels, temperatures, geological substrate, and genetic heritage are such that forests (with their attendant non-plant species: microorganisms, fungi, and animals) tend to cover the undisturbed land. Forests can spring up on bare ground in this region in less than a century! To describe this phenomena in another way, forests are the typical “climax communities” or biomes for this area – barring unusual abiotic events (such as flooding, hurricanes, ice storms, or fires caused by lightening, etc.) or intervention by biological entities such as us humans, beavers or some devastating pathogens. The term “Temperate forests” can also be used to describe these same climax communities, yet of course, as you might expect, there are many more precise characterizations of the ecosystems that arise.
At this point, it’s worth emphasizing that the long-lived, woody plants are only the most obvious components of these intricate communities. The forests are composed of closely interacting species who work together to create persistent self perpetuating sets of interactions. The sequence of species constellations that appear and disappear on ‘open’ land can be thought of as a sort of parade through time leading to the emergence of the more persistent, stable climax forest community.
This process of forest succession is a ubiquitous pattern that pervades and shapes our daily lives here in the Northeast, causing effects that range from the obvious to the subtle in this marvelous place we call home. From the ‘weeds’ by the roadside or the raspberries on the forest edge, to the types of birds we hear singing, forest succession is a particularly sophisticated and beautiful pattern that’s generated as those constellations of species appear and disappear across time, given our rainy terrain with its relatively wide but regular range of seasonal temperatures (At least this was the case prior to anthropogenic ‘climate change!’)
To go beyond a superficial appreciation of forest succession, attention to detail is required, and this must be combined with either a long memory or good access to the collective memory embodied in science texts and / or historical artifacts. As a Pattern existing in both space and time, forest succession is a product of various important phenomena and processes including Energy and Matter Flow, Cycling and Conservation. It also embodies relationships between Structure and Function; Cause and Effect; Scale, Proportion and Quantity; Systems; Stability and Change – in other words, all seven of the Crosscutting Concepts highlighted in the current Next Generation Science Frameworks
Because Forest Succession is so complicated and because it unfolds across long swaths of time, older students (with more science training) will be best prepared to grasp this pattern’s intricacy and sweep. However, with thoughtful guidance and humane logistics (particularly in terms of student teacher ratios and established, long-term interactions between teachers and children and the sites being studied), even very young people can begin to appreciate this vital and fascinating phenomenon.
This little illustration (adapted from “Yankee Lands,” a land use curriculum developed by the Antioch New England Graduate School in Keene, NH ) can be a helpful visual complement to youngsters’ field studies and discussions. You can increase its eidetic potential by encouraging students to interact with the imagery by adding colors (and perhaps animals) to the illustrations. Even better, you could suggest that they reinterpret the cycle of forest succession by using this worksheet as merely one of several initial references. Students could then create their own original drawings, collages, or paintings of the key stages and actors in Forest Succession. The resulting art projects, good examples of STEAM project-based learning, might be large, team-created murals or posters. These would not only illustrate the students’ understanding of the concept, but they could be shared / exhibited in real life or electronically for other members of the learning community .