Human activity (e.g. harvesting) represents one of the most frequent disturbances in forest ecosystems. Recent documents from the European Commission (2023) states that future forest management in the Union should focus on practices that ensure the various contributions forests provide to humanity, with particular emphasis on biodiversity conservation and climate change mitigation. Furthermore, there is a recognized need to safeguard natural dynamics as much as possible and to draw inspiration from them in order to propose management systems that reduce the severity of disturbance caused by timber harvesting. The aim of this work is to propose a universal ecological principle—the Energy Equivalence Principle (EEP)—as a guideline for closer-to-nature silviculture. The principle states that the density of individuals in different size classes scales inversely with the resource consumption of that particular size class. Under this condition, each size class consumes a constant amount of resources. Using tools from statistical mechanics, it can be demonstrated that this distribution is the one that optimizes the overall use of available resources. This work presents some empirical tests showing that, in forests approaching old-growth conditions, community structure aligns with the predictions of the EEP, while forests that have experienced disturbances exhibit structures that deviate significantly from those of optimal resource use. It is therefore possible to offer forest managers a universal structural-functional model (i.e., one applicable to forests worldwide) that can guide interventions to minimize the impacts of human activity and help steer forest communities toward greater functional efficiency—and, consequently, greater stability.