Removal of the Fittest: The Dangers of High-Grading

A primary rule of sustainable forestry is DO NOT “high-grade” your forest.  High grading is the selective cutting of only the most valuable (i.e. biggest and best quality) merchantable tree species.  This is often done as a “diameter-limit cut”, in which all the well-formed stems of commercial species greater than a certain diameter (i.e. usually about 16 inches) are logged.  While this can also be vaguely described as a “selective cut,” which leaves some trees, it is only the smaller (i.e. slower growing), poorly formed, unhealthy, or less economically valuable trees that are left standing in the forest.  This leaves a less diverse, degraded forest with poorer genetics that is on a negative trajectory.  High-grading is essentially the “removal of the fittest.”

Example of high-grading where the majority of large, valuable trees have been removed, leaving behind only smaller, poorly formed trees to regenerate the site (Mary Ann Fajvan, West Virginia University, Bugwood.org).
Example of high-grading where the majority of large, valuable trees have been removed, leaving behind only smaller, poorly formed trees to regenerate the site (Mary Ann Fajvan, West Virginia University, Bugwood.org).

The resulting forest after a high-grade is less valuable both economically and ecologically.  Not only is the timber quality of the residual stand reduced, but bigger, healthier trees produce more food and provide better habitat for animals from birds to deer to bears.  In particular, oaks are some of the most valuable species economically and ecologically, as they produce valuable, high quality timber and provide the best source of long lasting food (i.e. acorns, called “hard mast”) for wildlife in the forest.  High grading of oaks is particularly damaging as oaks are already having a hard time regenerating and face many threats to their health (e.g. oak decline, oak wilt, and gypsy moths).  Once an oak stand is high graded, it is likely that the oaks, which need a head start and some sun to compete, will not come back.  Throughout the Appalachians, oaks are being replaced by more adaptable, but less valuable (i.e. both as lumber and to wildlife), shade-tolerant trees like red maple.

Timber buyers (e.g. loggers, mills, investors) – and even some traditional for-profit foresters working on commission – often like to do high-grade cuts as it allows them to maximize their profits with minimal work, while the forest, which they do not own, is devalued.  EcoForesters is a nonprofit and never works on commission, but always keeps the forest’s and the landowner’s best interest foremost.  Our aim is to enhance the forest in the long run through positive impact forestry which increases both species and structural diversity, thereby improving wildlife habitat and forest resiliency to future threats like climate change and invasive species.  Sustainable forestry practices need to consider what trees are being left and are regenerating to form the future forest.  To leave a healthier, more diverse, forest increasing in fiscal and environmental value, a mix of lower quality, different size trees of more common species need to be harvested along with some more saleable ones to ensure that forest stewardship is ecologically sound, socially responsible, and economically feasible.