Which of the following is not a problem of forest management?

Planting different varieties of timber is not a problem of forest management. It is actually a solution to the problem. The idea behind planting different varieties of timber is to improve the health and diversity of the forest ecosystem, which can make it more resilient to pests, disease, and other threats. By planting different types of trees, forest managers can also create a more varied and sustainable source of wood and other forest products, which can help to support local communities and economies.