The average height of a birch tree is around 40 feet tall, but the paper and yellow birch can grow up to 80 feet tall. Of the 60 different types of birch trees, the most notable are the paper, European white, gray and yellow birch. Birch trees thrive in moist soil and full sunlight. Dry conditions are unfavorable for the tree due to its shallow root system.
Large birch trees are easy to maintain and are used in the manufacture of many items, including furniture, skateboards, guitar amplifier, railroad ties, medicine and fuel. Birch leaves are oval- or elliptical-shaped and range in color from light- to forest-green in the summer to yellow, orange and brown in the fall. Birch trees are noted for their peeling bark that begins as a brown color and turns white as it ages.
The paper birch is native to North America. The smooth white bark and ornamental green leaves of the paper birch make it a favorite for its beauty. The European white birch is often seen in urban areas. This tree has a smaller stature than the paper birch but is notably colorful in the fall. The gray birch has a tall trunk and is the only birch that does not have peeling bark. The yellow birch has a vast root system and takes an extended time to grow to full height. The bark of this tree curls and has a golden-yellow to yellow-orange color.
Eleven of the approximately 60 species of birch trees around the world are endangered, mostly due to habitat destruction and fungal infections. The birch is regarded as a pioneer species because it commonly grows in places destroyed by fire. With the proper conditions, some species can grow as high as 80 feet.
In the northern hemisphere, birch trees contribute significantly to allergies; they are responsible for 15 to 20 percent of the cases of hay fever there. The tree has a life span of 30 to 200 years depending on the species and environment. Birch is widely used for firewood, as its wood is highly flammable, even when wet.