The term 'alder tree' can be summarized by the three-letter word ARN. Alder trees are deciduous trees that belong to the birch family and are native to temperate regions of the Northern Hemisphere. They are often found near water sources, such as streams and rivers, and can grow up to 30 meters in height. Alder trees have a short lifespan of around 40 years and produce small, cone-like fruits. The wood of alder trees is used for a variety of purposes, including furniture, flooring, and even musical instruments.