Northern Hardwood Forests of the Adirondacks
The northern hardwood forest is the most extensive woodland in the Adirondacks. It occupies the region's best soils and sites, growing on the more fertile soils that make up glacial till. The northern hardwood forest is generally found on the lower and warmer mountainsides – gentle slopes where soils are neither extremely dry nor extremely wet.
The most dominant life form in the northern hardwood forest are deciduous trees, which lose their leaves each fall and are almost completely dormant in the winter months. One of the most striking characteristics of the northern hardwood forest is the extravagant display of fall colors, which result from the loss of green pigment, chlorophyll, as the trees slow down their photosynthesis in the autumn and prepare to enter dormancy for the winters. With the chlorophyll is gone, pigments which were hidden previously become visible, producing the vibrant reds of the Sugar Maple and the golden yellows of the American Beech.
Northern hardwood forests in the Adirondacks can be recognized from afar by the color and pattern of foliage.
- In spring, before leaf-out, the grey-brown pattern of unleafed branches contrasts with the somber dark green expanse of conifers both above and below the hardwoods.
- In summer, hardwood forests can be distinguished by areas of bright green foliage.
- In fall, the oranges, yellows, and reds of deciduous trees stand out against the dark greens of the conifers.
Trees of the Northern Hardwood Forest
The two dominant tree species are Sugar Maple and American Beech, both of which can tolerate more shade than other hardwoods and thrive on deep, fertile, well-drained till. Also present in some areas is Yellow Birch, which requires somewhat more sun and does well on both till and outwash, and Eastern Hemlock. The mix of trees on any given site varies with the elevation, soil, topography, and water table.
Sugar Maple is a food source for several wildlife species. White-tailed Deer, Moose, and Snowshoe Hares commonly browse on Sugar Maple trees. Red Squirrels feed on its seeds, buds, twigs, and leaves. Porcupines eat the bark and can girdle the upper stem. A number of birds build nests in Sugar Maples, including American Redstarts, Evening Grosbeaks, Baltimore Orioles, and Northern Cardinals. For several species – including the Cerulean Warbler, Scarlet Tanager, Hairy Woodpecker, and Summer Tanager – the Sugar Maple is one of the preferred trees for foraging for insects.
Beech nuts are an important source of food for wildlife, including Raccoons, White-tailed Deer, Porcupines, and Foxes, as well as squirrels and chipmunks. Beechnuts are also consumed by Black Bears, who load up on calories for winter hibernation. The American Beech also provides food and nesting sites for a variety of birds. American Beech are used as a nest site by Cooper's Hawks and American Redstarts. American Beech trees provide nest cavities for cavity nesters, like the Wood Duck. Beechnuts are an important food source for Blue Jays, Red-headed Woodpeckers, White-breasted Nuthatches, and Red-bellied Woodpeckers.
Shrubs of the Northern Hardwood Forest
The understory of the northern hardwood forest includes several species of shrub:
Another common understory plant is Snowshoe Hare; Red Squirrels and Eastern Chipmunks eat the seeds. Striped Maple is frequently eaten by North American Porcupines. The Striped Maple also provides browse for White-tailed Deer and moose. Striped maple are also very useful to wildlife in that these understory plants help diversify the vertical profile of a forest, creating the dense layers in a woodland that are attractive to many wildlife species for nesting, feeding, and perching.
Wildflowers and Ferns of the Northern Hardwood Forest
The wildflowers and ferns that flourish in the deeply-shaded forest floor of a mature northern hardwood forest are those that are very tolerant of shade. The only sun-loving wildflowers which bloom in a mature hardwood forest are found on the edges of wide trails or in places where a blowdown or other disturbance has created a gap in the tree canopy.
spring ephemerals. These are perennial woodland plants that sprout from the ground in deciduous forests in early each spring, then quickly bloom and seed before the canopy trees overhead leaf out. Once the leaves of the deciduous trees above are fully-developed and the forest floor is deep in shade, the foliage of these plants wither away leaving just the roots, rhizomes, and bulbs underground.
Spring ephemerals that bloom in the Adirondack Mountains include Trout Lily, Squirrel Corn, Carolina Spring Beauty, and Dwarf Ginseng. You can also find many of these plants in mixed wood forests, but almost always under deciduous trees. These little plants emerge, bloom, and die back very quickly, sometimes (depending on the weather) in a matter of a few days, so nature lovers seeking to find them need to carefully time their spring wildflower walks.
shade-tolerant wildflowerscommon in northern hardwood forests in our region include Purple Trillium, Indian Cucumber-root, Jack-in-the-Pulpit, Canada Mayflower, Starflower, and Wild Sarsaparilla. Most bloom in the spring, many in dappled sunlight before the leaves of the maples and beeches above have fully developed. Many of these plants may also be found in mixed wood forests, often in proximity to a group of deciduous trees.
Interrupted Fern, Hay-scented Fern, Intermediate Woodfern, and New York Fern. Two fern allies – Shining Clubmoss and Tree Clubmoss (or Ground Pine) – are also found in this habitat in abundance.
Wildlife of the Northern Hardwood Forest
Many of the mammal species who live in this habitat, like the Eastern Chipmunk, Gray Fox, and Fisher, can also be found in mixed wood forests. Others, like the White-tailed Deer, can also be found in farmlands and the brushy areas of successional fields.
- Butterflies often seen in this habitat include the Eastern Comma, Spicebush Swallowtail, and Canadian Tiger Swallowtail.
- Moth species include the Rosy Maple Moth, Promethea Silkmoth, Polyphemus Moth, and Luna Moth. Deciduous trees provide a host plant for several of these moths, such as the Rosy Maple Moth, preferred host is the maple tree. Caterpillar hosts of the Luna Moth include Paper Birch, while the Polyphemus Moth lays its eggs on a variety of deciduous trees, including birch, maple, and beech.
Amphibians and Reptilesof the Adirondack hardwood forest include the Eastern Red-spotted Newt, Spotted Salamander, American Toad, and Common Garter Snake. Some are generalists, like the Common Garter Snake, and are found in many terrestrial habitats.
The Eastern Red-spotted Newt only appears in this habitat during its terrestrial stage, when it is known as a Red Eft. These creatures begin life as aquatic larval newts, then transform into brightly-colored Red Efts in their terrestrial stage. Red Efts spend several years on land, then return to water, transforming into aquatic adults. Red Efts are mostly diurnal. Look for them in the leaf litter of the forest floor. The bright orange color warns predators of their toxic skin secretions.
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