Native trees are those that live in areas where they naturally evolved. Over geologic time, trees adapt to soil, climate, and cycles of rainfall and frost. They evolved to live with local insects, fungi, bacteria and other natural stressors. They are ordinarily more hardy in their regions of origin than hybrid or imported trees, and their beauty is often unsurpassed.
Native vs. Alien Trees
Alien trees are those that have been imported to an area. Some trees produce commercially useful fruits or nuts. Other trees are colorful or are useful for lumber, shade or windbreaks. Unfortunately, some imported trees bring with them insects and diseases that afflict native trees. Some imported trees, finding no natural resistance, spread aggressively, crowding out native trees and plants. Trees do not have to come from another continent to be alien; they can also be imported from a different part of the same continent or country.
Benefits of Native Trees
Because native trees are adapted to local soil and weather, they generally thrive with a minimum of care. They generally require less fertilizer and fewer applications of pesticides. If fewer chemicals are used in their maintenance, fewer chemicals are found in runoff that empties into rivers, streams and estuaries.
Native Trees and Wildlife
The wildlife in most regions have evolved to depend on native trees for food and shelter. Native trees are essential to the survival of numerous animals from koalas, squirrels and birds to insects, bees, butterflies, and browsing deer and moose.
North American Native Trees
In general, the central and eastern parts of North America have numerous varieties of deciduous native trees, including ash, birch, maple, alder, oak, beech, laurel and hickory. Those trees account for the spectacular displays of color in the fall throughout the Eastern Seaboard of the U.S. up into Canada.
Although the western areas of North America have many of the same kinds of trees as the east, there are far more evergreen and coniferous trees in the west, including native varieties of aspen, cedar, spruce, fir, hemlock, pine, cypress and yew trees. Many of those native evergreen trees are found at altitude in the Rocky Mountains and the mountains of the west coast from California to British Columbia.
Australia and the UK
Because of its geographic isolation, some of the most unusual native trees in the world are found in Australia. Those include the Boab tree in western Australia; the Pandamus tree of eastern Australia that grows thick, udder-like roots to prop it up; the stinging tree of Queensland; the strangler tree that reproduces itself from seeds in bird droppings that land on other trees; and the Wollemi pine of New South Wales, one of the oldest and rest trees in the world.
Many trees native to the UK, from alders and willows to pines and sycamores, found their way to North America by immigrants.
Finding Native Trees
Most states, provinces and countries have more than one geographical area. Those different climates and sub-climates produce different kinds of native trees.
Numerous native plant societies in U.S. states and Canadian provinces maintain lists of native trees. Those lists ordinarily take into account trees that evolved in different regional climates.
Many nurseries sell native trees, as they are becoming more fashionable because of a general awareness of environmental concerns.