 If there are too few trees in a class, the forester will determine if it is necessary to reduce the removal of trees from neighboring classes to maintain an ideal q-ratio.The goal of the use of a BDq curve is to ensure the continued development of trees in each age class, and the continued availability of mature timber to harvest on a relatively short cutting cycle (8–15 years).Longer cutting cycles may be used depending on species mix, silvicultural goals and if the aim is amenity or economic forestry in respect to the land.