Stress is a condition where a system, or its parts, begins to operate near the limits for which it was designed. Strain is disorder and disruption of a system due to operation beyond the limits of stress. Survival means that you stay alive and you stay in a working state under conditions that have the capacity or the ability to kill you. High quality means as it survives it survives in a state that will continue to be usable. Low quality means if it does survive it will be in a state that will not be usable.
Health is the ability to resist strain.
Old forestry is forestry without the understanding of tree biology, i.e., they make decisions without understanding trees biology. Soil is a substance made up of sands, silts, clays, decaying organic matter, air, water and an enormous number of living organisms. Keep these for future use. The question is how best to increase National Forest Health of Sustainability. Present practices or theories involve the following forest treatments due to commercial logging interests.