An evaluation of tree marking methods for implementing spatially heterogeneous restoration

Silviculturists are increasingly focused on the development of structurally complex forests through spatially heterogeneous treatments; however, the implementation of these treatments is challenging. We investigated the effectiveness of three tree marking methods used to implement spatially heterogeneous restoration treatments on Colorado’s Front Range: Individual Tree Marking (ITM) physically marks all trees that are either to be cut or left; Designation by Description (DxD) provides a description of the trees that are to be removed based on specific tree characteristics; and Designation by Prescription (DxP) provides the operator with a description of the desired outcomes of the treatment. We employed a mixed methods approach by (a) quantitatively comparing the heterogeneity of stands that have been treated; and (b) interviewing personnel involved in the implementation of these treatments to qualitatively evaluate their efficiency and effectiveness. Neither the quantitative nor the qualitative study methods found a single marking method that was superior to the others in all respects. However, several factors should be considered when selecting a tree marking method, including: the need to set clearly defined silvicultural objectives; personnel experience; trade-offs among personnel; the use of hybrid marking methods; and the range of acceptable outcomes.