The forest has a thousand eyes
but you have only two—
And that is why the birds are wise
to everything you do!
amber: Fossilized tree resin. Resin is similar to sap, oozing from a broken branch or from damaged bark. Insects and tree seeds can be caught in the sticky resin and completely preserved. Several sites around the world are known for amber. The amber from the Dominican Republic is about 20 million years old. Amber from Canada is about 65 million years old.
annual rings: Also called growth rings. As a tree grows, new layers of wood are formed each year. When a tree is cut down and the flat end of the stump is sanded smooth, you can see each year’s growth as a ring or circle.
A veery rests on a balsam fir. The veery, found across most of southern Canada and the northern United States, is a forest bird with a unique song. The song is often described as a downward spiral, twirling rapidly downward like notes running down a spiral staircase.
arboretum: A public sanctuary for trees and shrubs. It’s not a forest but a place where many trees and shrubs have been planted. Labels or signs identify each species. An arboretum may have rare trees or trees from other countries.
arborist: A tree-care professional who has had special training in planting, selecting, and pruning trees. Many large towns or communities have an arborist on staff, who can give the right care to trees that have been damaged in a storm or affected by insects.
botanist: A scientist who studies plants. A botanist might specialize in trees, shrubs, wildflowers, mosses, ferns, or other plants.
canopy: The upper parts of a mature tree: all the branches and twigs that support leaves. A sugar maple is a good shade tree because it has a spreading canopy that provides shade all summer.
carbon dioxide: A gas in the atmosphere that animals (including people) exhale. We breathe in oxygen from the air, and then we breathe out carbon dioxide.
catkin: A long dangling cluster of tiny flowers. Birch trees produce catkins with seeds, which are eaten by some forest birds. Many people are familiar with the shorter fuzzy catkins on pussy willow shrubs.
chlorophyll: The green coloring (a chemical pigment) in the cells of plants.
circumference: For trees, a measurement taken around the trunk, about four feet from the ground. Wrapping measuring tape around the trunk is the easiest way to measure the circumference.
conifer: A tree that produces its seeds in woody cones. Pines, spruces, and firs are conifers. While they often are called evergreen trees, this is misleading. Some conifers, like the tamarack (larch), have cones, but their needles are not evergreen—they turn yellow-gold and fall off in the autumn.
cultivar: A cultivated variety. A tree or shrub that is developed, propagated, and grown from a wild species for use in gardens or landscaping. Many different species have cultivars, including hawthorn, apple, and red maple trees.
deciduous: Trees that lose their leaves each autumn. Maple, oak, birch, and ash trees are examples.
dendrologist: A botanist who studies trees and shrubs.
diameter: The measurement across a circle. The diameter of a tree that has been cut down can be measured by holding a ruler or tape measure across the widest part of the stump.
diversity: The number or abundance of different species living in an area. The diversity of wildlife in a healthy forest is greater than the diversity in a small city park. The diversity of insects and birds in a swamp is likely to be much greater than in a dry desert.
drought: A lack of rain. A period of time when there has been no rain or very little rain.
ecology: A science that examines the animals and plants that live together in an environment. A healthy forest ecology includes trees, shrubs, wildflowers, ferns, and other plants that live there—and all the animals (such as birds, mammals, reptiles, amphibians, and insects) and other life that can find food and make nests or dens there. The ecology of an area also includes the climate and soil conditions.
ecologist: A scientist who studies ecology. An ecologist may specialize in forest ecology, desert ecology, lake and stream ecology, or the ecology of a special area like the Arctic.
edge habitat: The area where two different habitats meet, such as where a large field meets the edge of a forest.
entomologist: A scientist who studies insects.
environment: The habitat, climate, and soil conditions of an area.
fascicle: On a pine tree, the needles grow together in a bundle (the fascicle) attached to the twigs. Pitch pine needles grow in fascicles of three, but the needles of an eastern white pine grow in fascicles of five.
field notes: Written notes about what you observe outdoors. Good field notes include the date, time, and place of your observation—and even drawings made on the spot “in the field.” Field notes and field drawings help to document what you have seen, because you can’t remember everything!
heartwood: The inner wood of a tree. You can see heartwood on a tree that has been cut evenly across: there will be a darker central area, surrounded by the outer layer—the sapwood, which is lighter in color. Many species of trees do not show a difference in color, but red oaks usually do.
larva (plural: larvae): An immature insect. A caterpillar is the larva of a butterfly or moth. The larva of a beetle is usually called a grub.
mulch: A layer of old leaves, cut grass, or pine needles that is placed on the ground around a trunk. Mulch helps to keep the soil below from drying out, and is very helpful during a drought. You can buy “bark mulch” from a garden center.
native: Growing naturally wild. Blue spruce is native to some of the western states but is often planted in the east (as a cultivated variety) for landscaping. Weeping willows are native to China but are planted in many other countries because they are beautiful trees.
old-growth forests: Forests or stands where most of the trees are at least 100 years old. Some old-growth forests have trees hundreds of years old—or even 1,000 years old! Typically, no home construction, lumber cutting, or other damage caused by people is present in old-growth forests.
oxygen: A gas in the atmosphere that people and other animals need to breathe. Trees need some oxygen too, but they produce more oxygen than they need. Trees and forests are important in replacing oxygen in the atmosphere.
petiole: The leaf stem. The leaves of some species have a very short petiole, while the leaves of other species may have long petioles.
pollen: The tiny, nearly microscopic grains that are produced by the male parts of plants. On flowers, the pollen usually comes from the anthers, held on tiny stalks surrounding the central pistil (the female part).
range: The natural, normal area where a plant grows. The normal range of the black walnut tree, for example, does not reach into northern New England, but many have been successfully planted in the state of Maine.
riparian: Near or along rivers and streams.
samaras: Most tree seeds that have a wing or blade. Maple, ash, and spruce seeds are called samaras. Most pine seeds have wings but are usually not called samaras.
serrated: Saw-toothed. The leaves of red maple and American elm have serrated edges.
shrub: A plant that usually has several woody stems rising right from the ground. Shrubs typically grow less than 15 or 20 feet tall. (Trees grow taller and usually have just one main trunk.)
snag: A dead or decaying tree that has had its crown and branches broken off (sometimes by a lightning strike). The decaying trunk may remain upright for many years. Snags contain many insects, which are an important food source for woodpeckers and other birds. Woodpeckers will often peck holes in snags for nesting sites.
species: One type of plant or animal. The trees of one species have a similar leaf shape, bark texture, flower or seeds, and general structure. There are many species of maples, for example, and each one can be identified by the shape of its leaves, its overall structure and size, its type of bark, and the flowers or seeds it produces.
stand: A forested area or woodland of at least five acres; a kind of small forest.
strata: The different layers or levels of a forest where the plants and animals live. The bottom layer includes the dirt and leaf litter. The next layers consist of small plants like wildflowers; then the understory of woody shrubs; and then the highest strata, the upper canopy, which includes the branches and leaves at the tops of the trees.
tree: A tree usually has a single main trunk and grows more than 20 feet tall. (Most shrubs are smaller and often have several branch-like trunks.)
tuckamore: Groups of short, stunted balsam firs and spruces, found mostly in northern areas, and especially in Newfoundland, Canada. Blown by constant strong wind, even mature tuckamore firs are only about four feet tall.
understory: The plants and small woody shrubs that grow in the forest, under the taller canopy of the trees. Blueberry and azalea are good examples.
Trees are listed here by family, in the order you are likely to find in most field guides.