Which tool is commonly used to measure tree height?

The use of a clinometer or hypsometer for measuring tree height is based on its specific design and functionality, which allows for accurate height assessment. A clinometer utilizes angles and trigonometric calculations to determine the height of a tree based on the observer's distance from the tree. By measuring the angle of elevation to the top of the tree and knowing the distance to the base, one can effectively calculate the height. Similarly, hypsometers, which may be handheld or more sophisticated tools, operate on similar principles but can include additional features for easier use in forest environments.

In contrast, while a tape measure could theoretically measure tree height by measuring the distance straight up from the ground, this method might not be practical for tall trees or in uneven terrain. A digital camera isn't designed for direct measurement of height, and although it can offer visual data that might assist in height estimation through other methods, it does not provide a direct height measurement. Lastly, a wind gauge measures wind speed and direction, which has no application in measuring height. Therefore, the clinometer or hypsometer is the most suitable and commonly used tool for this specific purpose in forestry work.