Red maple (Acer rubrum) is a common and widespread tree species that has grown only more abundant as North America’s forests have been repeatedly logged and forest composition has shifted with the deletion of once-common species like American elm (Ulmus americana) and American chestnut (Castanea dentata) which suffered near extinction in the wild due to introduced diseases. Red maple ranges far north into Canada, and to the south into Florida, and holds territory as far west as Texas and Oklahoma.
Red maple is what’s known as a “generalist tree species” because it thrives across a broad spectrum of conditions and can tolerate a variety of stresses, from living in a suburban yard to a crowded secondary forest thick with new growth…but its real achievement is that it’s able to live in the wettest of forest habitats. In the northeast, red maple swamps are a common plant community, often blanketed in sphagnum and sedge dominated wetlands, with soft mucky soil and a host of other plants that tolerate seasonal flooding or a year-round elevated water table. Walking through a mainland deciduous forest in fall or driving along a highway bordering a marshy area or swamp, the New England landscape is punctuated by incandescent crimson, the characteristic color of red maple foliage during autumn.
On Nantucket, as always, things are a bit different. Red maple trees here on island are almost exclusively found in wooded swamps, with a few scattered individuals in upland mixed deciduous forest in areas like Squam and Norwood. In the island’s swamps and edging our vernal pools, the red maple reigns supreme. Our old red maples are gnarled, lumpy, many-trunked, and prone to being toppled in storms. Even they, who are extremely tolerant of “wet feet,” have their limits! Roots need to be closer to the surface in wetlands to get enough oxygen, so the root plate of the red maple is shallow by necessity but spreads widely filling an area about the size of the tree’s canopy. As the soil in these wetlands is soft and mucky, a strong storm can topple a red maple in a wetland more easily than a tree higher up on a hill and more directly exposed to stronger winds. Trees have an easier time staying upright when the soil is firmer and has some rocks and texture to it, as in our sandy hills.
But the maple has a few tricks up its sleeve—it can be toppled yet still have intact roots on the side of the root plate still in contact with the soil. If a tree is toppled in fall or winter, it will often leaf out in the spring and then make an impressive recovery by changing its game entirely. Branches on the upper side of the downed trunk will start to turn upward to catch the sun, eventually becoming upright trunks as the old tree trunk gradually decomposes. Former canopy limbs that now touch the ground can spontaneously grow new roots into the soft wet soil, in a process called tip layering.
And from the root plate of the tree, now often standing perpendicular to the ground, the fallen tree can send up new trunks that grow vertically to reach toward the sun. Meanwhile, the hollow area the tree roots once occupied will often become a pool filled with water, or a tentlike shelter for wildlife to hide within a cavelike root system.
These caves, hollows, and pools quickly become suitable habitat for spotted turtles, who may spend the winter underwater in caves where the tree roots protect them from many predators and the water keeps them at a cold and fairly consistent temperature suitable for brumation, a form of winter dormancy. One of these tip-ups often becomes a winter home for a literal pile of turtles, well-hidden and protected through the cold months in a subterranean pool. As the seasons pass since a tree is uprooted, the shallow hollows at the surface are filled with water, often acquiring a blanket of sphagnum mosses, and transforming into great habitat for vernal pool species such as fairy shrimp (Eubranchipus spp.) and water fleas (Daphnia spp.). An array of other creatures like tiny spring peepers (Pseudacris crucifer) and four toed salamanders (Hemidactylium scutatum) rely on the vernal pools for breeding habitat as well.
Meanwhile the red maples carry on and begin blooming anywhere from late February to late April depending on the temperature trends. Red maple twigs redden as the sun’s intensity grows, and the round red buds swell with rainfall and warmer temperatures until the blossoms expand to reveal the bright red to coral-colored flowers. Red maples are as adaptable in their pollination habits as they are in the forest ecosystem. A tree may have all male flowers, all female flowers, or some of each among its branches depending on the individual. Male flowers are easy to identify because they sport anthers rich with golden pollen. Females become more obvious as the flowers are pollinated and begin to form the familiar winged samaras or keys, that are the red maples’ seeds.
Also known as “helicopters” for their ability to spin and twirl in the wind, these seeds may be carried far from the mother tree by wind, or gathered up by forest birds and squirrels or other rodents for food.
2021 appears to be a year when the red maples are on the later side for blooming, so be sure to keep an eye out walking on the trails in the coming days and weeks of April. Red maple floral displays are particularly striking on a “bluebird sky” day as the flowers open amid the tracery of leafless branches. They are also a great pollen and nectar source for honeybees and a myriad of native bees and other hungry insects in early spring long before many other trees or wildflowers bloom. If you walk an area with red maples regularly through the seasons, you can watch the show unfold as spring blossoms transform into ruby-red maple keys suspended in a green canopy, and then gradually burst into the crimson of fall foliage.