Which of the following is a method to improve the architecture of a tree?

Reducing the size of the crown is an effective method to improve the architecture of a tree because it can help manage the tree's overall structure and balance. When a tree’s crown is too large, it may lead to issues such as excessive weight distribution, which increases the risk of branch failure. By selectively reducing the crown size, you can enhance light penetration and air circulation within the tree, which fosters better growth and reduces the chances of disease. Proper crown reduction also encourages the development of a more stable and aesthetically pleasing tree form.

While planting more trees nearby can contribute to an overall healthier ecosystem, it does not specifically improve the architecture of an individual tree. Similarly, removing low growth is a technique often used to enhance visibility or access but may not address the structural balance of the tree's upper sections. Incorporating mulch around the roots is beneficial for moisture retention and soil health but does not directly impact the architectural aspects of the tree itself.