How To Identify Wood By Bark

Ever wondered if you could tell a tree’s story just by looking at its skin? While leaves and flowers offer clues, they're often seasonal. Bark, however, is a year-round identifier, a constant record of a tree's life etched into its outer layer. Learning to "read" bark allows you to recognize trees even in the dead of winter, understand their age and health, and even appreciate the intricate beauty hidden in plain sight.

Whether you're a seasoned hiker wanting to identify trees along a trail, a homeowner curious about the species in your yard, or simply someone who appreciates the natural world, bark identification is a valuable skill. It opens a new dimension to understanding the plants around us and fosters a deeper connection with the environment. It’s also surprisingly practical, offering insights into wood properties and potential uses.

What does bark tell us about a tree?

How does bark texture help identify tree species?

Bark texture is a key characteristic that aids in tree species identification because different tree species develop unique bark patterns, colors, and structural features as they mature. These variations arise from differences in the tree's growth rate, defense mechanisms against environmental stressors, and the specific arrangement and composition of cells within the bark itself, creating a visual fingerprint for each species.

The bark's appearance changes over time, making it essential to consider the tree's age when identifying it based on bark characteristics. Young trees often have smooth, thin bark, while mature trees develop more complex textures, such as ridges, furrows, plates, scales, or even peeling layers. The depth, width, and orientation of these features can be highly specific to a species. For instance, the deep, diamond-shaped furrows of a mature White Ash are quite distinct from the smooth, gray bark of a young American Beech, or the shaggy, peeling bark of a Shagbark Hickory.

Furthermore, factors like the tree's environment and growing conditions can influence bark texture. Trees in harsh environments may develop thicker, more protective bark. Observing bark characteristics along with other identification features such as leaf shape, branching patterns, and overall tree form, provides the most accurate method for identifying tree species. Although diseases and injuries can alter bark appearance, the underlying texture pattern often remains recognizable to those familiar with a particular species.

What bark characteristics change with tree age?

Bark undergoes significant transformations as a tree matures, impacting its appearance, texture, and function. Young trees typically have smooth, thin bark, often displaying prominent lenticels (small pores for gas exchange). As the tree ages, the bark thickens and develops a more complex structure, exhibiting variations like ridges, furrows, plates, or scales, influenced by the tree's growth patterns and environmental factors.

The shift from smooth, thin bark to thicker, textured bark is primarily due to the continuous production of new layers of phloem (inner bark) and cork cambium (outer bark). The outer layers of bark, lacking living cells, gradually die and are pushed outwards by the expanding circumference of the tree. This process causes the bark to crack, split, and develop its characteristic patterns. The speed and manner of this transformation vary significantly among different tree species. For instance, some species, like beech, may retain relatively smooth bark even at maturity, while others, like oak, develop deeply furrowed, rugged bark. Furthermore, color changes often occur with age. Younger bark might be a lighter shade of brown, gray, or even reddish, while older bark tends to darken. The presence and abundance of lichens, mosses, and other epiphytes can also alter the apparent color and texture of older bark, further complicating identification. Finally, the overall pattern of bark exfoliation (shedding) changes with age. Some trees, like birches, shed their bark in thin, papery layers, while others, like sycamores, shed it in large plates, revealing patches of underlying bark with a different color and texture.

Can bark color reliably identify a tree?

While bark color can offer clues, it's generally not reliable as a sole identifier for tree species. Bark color is influenced by factors like age, sun exposure, moisture levels, and even the presence of fungi or lichens, leading to considerable variation within a single species and overlap between different species.

Think of it this way: the bark of a young birch tree is often bright white, but as it matures, the color can darken and become more textured. Similarly, the south-facing side of a tree's trunk often develops a different color due to greater sun exposure compared to the north-facing side. Certain tree diseases or growths can dramatically alter the bark's appearance, masking its true coloration. Therefore, relying solely on color can easily lead to misidentification.

To accurately identify a tree using its bark, consider other characteristics in conjunction with color. These include bark texture (smooth, ridged, plated, furrowed, scaly, peeling), pattern (vertical fissures, diamond-shaped patterns), thickness, and the presence of lenticels (small pores). Examining the overall bark appearance, combined with leaf shape, branching patterns, and location, offers a far more robust and reliable identification method.

How do bark ridges and furrows differ between tree types?

Bark ridges and furrows, the raised and recessed patterns on a tree's surface, are highly variable among different tree species, reflecting differences in bark thickness, growth rate, and how the bark expands over time. Some trees exhibit deep, blocky furrows separated by thick, prominent ridges, while others have shallow furrows and flatter, less defined ridges; even the orientation (vertical, horizontal, or diagonal) and texture (smooth, rough, scaly) of these features vary considerably, creating distinctive bark patterns useful for identification.

The depth, width, and pattern of furrows and ridges are influenced by the way a tree's bark layers develop. For example, trees like mature oaks often have deeply furrowed bark with prominent, interconnected ridges. This is because their bark grows thick over time, and as the tree expands, the outer layers split and separate, forming these deep fissures. In contrast, trees such as beech typically retain a smooth, relatively thin bark, developing only shallow, subtle furrows as they mature. The furrows may also differ in color, with the inner bark exposed within the furrows being a different shade than the outer ridge surfaces. Consider also the patterns formed. Some species show continuous, vertically oriented ridges and furrows running the length of the trunk, like many pines. Others may display a more irregular or blocky pattern, such as the characteristic checkerboard bark of dogwoods. The presence of horizontal lenticels (small, corky pores for gas exchange) within the furrows or ridges can also be a distinguishing feature. Subtle nuances such as the sharpness of the ridges (rounded vs. angular) or the presence of scales or plates within the furrows further contribute to the unique "bark fingerprint" of each species.

Does bark thickness indicate tree species?

Yes, bark thickness can be a helpful indicator of tree species, though it's not foolproof and should be used in conjunction with other identification characteristics. Different species have evolved barks of varying thicknesses as adaptations to environmental pressures such as fire, temperature extremes, and insect infestation.

While bark thickness alone isn't a definitive identifier, it can significantly narrow down the possibilities. For example, trees in fire-prone regions, like some pines and oaks, often develop thick, insulating bark that protects the cambium layer (the living tissue just beneath the bark) from heat damage. Conversely, trees in cooler, wetter climates may have thinner bark. The specific structure and texture combined with thickness can create a more robust means of identification. For example, a thick, deeply furrowed bark suggests something different than a thick, but relatively smooth and corky bark.

Consider the contrast between a Shagbark Hickory, known for its thick, shaggy, peeling bark, and a Beech tree, characterized by its thin, smooth, grey bark. These distinct bark features are species-specific and provide valuable clues. However, it is important to consider the age of the tree and environmental factors, as bark characteristics can change as a tree matures and may be affected by the surrounding habitat.

Here's an example:

How does bark smell aid in tree identification?

Bark smell, though subtle, can be a valuable supplementary tool in tree identification, especially when combined with other characteristics. Certain tree species possess distinctive aromatic compounds in their bark that release recognizable scents when scraped, broken, or even just gently warmed by the sun. This olfactory characteristic can provide a confirmatory clue or, in some cases, a primary indicator of a tree's identity, particularly when visual features are ambiguous or unavailable.

While visual characteristics like bark texture, leaf shape, and overall tree form are typically the primary identifiers, bark smell offers another sensory dimension. The olfactory compounds responsible for these scents vary widely between species. For example, birch bark often has a characteristic wintergreen or menthol-like aroma due to the presence of methyl salicylate, while cherry bark might exude a distinct almond-like scent due to the presence of benzaldehyde. Other scents can be described as spicy, citrusy, resinous, or even resembling specific foods or chemicals. It's important to note that the intensity of the smell can be influenced by factors like the tree's age, health, and environmental conditions, making it crucial to rely on other identification markers in conjunction with bark smell. To effectively use bark smell for identification, it's advisable to gently scrape or break off a small piece of the outer bark (avoiding girdling the tree) and then sniff the exposed inner bark or freshly broken surface. It’s also vital to develop familiarity with common local species through repeated observation and scent comparisons. This sensory experience can refine your ability to differentiate between trees with similar visual features but distinct aromatic profiles. Furthermore, awareness of potential allergens or irritants associated with certain bark components is also important before smelling.

Are there specific bark patterns unique to certain trees?

Yes, many tree species exhibit unique and recognizable bark patterns, making bark identification a valuable tool for dendrologists and nature enthusiasts alike. These patterns are influenced by the tree's age, growth rate, environment, and genetics, leading to a wide variety of textures, colors, and fissure arrangements that can serve as distinctive identifiers.

Bark characteristics to consider include the color, texture, thickness, and overall pattern. Some trees have smooth bark, like the American Beech, even in maturity, while others develop deep furrows and ridges as they age. Consider the direction and arrangement of fissures. Are they vertical, horizontal, or interlacing? Do they create plates, scales, or blocky patterns? Is the bark peeling, exfoliating, or remaining tightly adhered to the trunk? The color can also be diagnostic, ranging from the silvery-white of a birch to the reddish-brown of a pine, or the dark gray of many oaks. However, relying solely on bark for identification can be challenging. Bark appearance can vary within the same species due to environmental factors such as sun exposure, soil conditions, and moisture availability. For example, a tree growing in a shaded, moist area may have a different bark appearance than one growing in a dry, sunny location. Furthermore, younger trees typically have smoother bark compared to older individuals of the same species. Therefore, it's best to use bark characteristics in conjunction with other identifying features, such as leaves, buds, fruit, and overall tree shape, for accurate identification.

Well, there you have it! Hopefully, you've picked up some handy tips to help you identify trees by their bark. It's all about observation and a little practice, so get out there, take a closer look at those trees, and see what you can discover. Thanks for reading, and we hope you'll come back soon for more nature-sleuthing advice!