<P> Better alternatives to tree topping, based on scientific research, are replacing the practice of tree topping . For example, size reduction can maintain the aesthetics and structural integrity of a tree without damage . Spiral thinning and other forms of canopy thinning can decrease wind resistance and allow wind to pass through trees, reducing the potential for branch failure due to wind - throw . Thinning also allows more light penetration and air circulation; both important to tree health . Other cultural practices include choosing plant material that will fit in the desired location at its mature size . </P> <Ul> <Li> Ulmus parviflora - Chinese Elm </Li> </Ul> <Li> Ulmus parviflora - Chinese Elm </Li>

The top of a tree is called what