The article discusses the concept of behavioral geography, defines its subject, basic methods, and models, showsthe difference between this approach and other areas of the theory of geographical science. Behavioral geography is analyzed within the intertheory of regulatory mechanisms in nature, society, and the economy – the interaction of components of integral geosystems that takes into account the peculiarities of the geographical environment as changing in time and space. A territorial object is studied in the local phase space of relative features that reflects the states of the individual system of behavior in space and time without taking into account the characteristics of the environment. The environmental geographic correction that binds the object to a specific territory is then factored in. Modeling procedures are based on ideas of differential geometry. From these metatheoretical positions, behavior is reflected by the Lagrange derivative formula and the Euler equation. There are distinguished holistic behavior, characterizing the trajectory of the geosystem as a whole, and the mechanical behavior, taking into account the mechanisms of interaction of parts of the whole in the control schemes, which unambiguously determines the subject of the intertheory of the behavior of systems. All this allows us to apply a broad arsenal of mathematical analysis methods used in mechanics, extending them to other processes in nature and society. There are distinguished stationary and non-stationary, stable and unstable, autonomous and non-autonomous behavior systems; the latter are associated with the impact of a variable environment and external management. Through the example of the life cycle of forest plantations, the paper describes the mechanisms of growth and self-thinning of stands in various geographical environments. We propose an algorithm of forecast modeling and mapping of forests with correction for completeness and site quality of plantations, based on similarity of time dependences of change in forest wood reserves. Forest geosystems are studied ‘in pure form’ for reference forests, and then, with the help of corrections, they are correlated with their environment, which regulates the behavior of a particular geosystem.