Studying the forest ecosystem and its natural laws for development and succession, it is noteworthy from the perspective of diagnosis of the state of systems, being organisations and even cities, to keep the sets of forest trees in mind, as found by Oldeman (1974a) in a diversity of forests. In the forest the main components are trees. In organisations it are people and on city level it could be organisations itself. It is the level of consideration which makes it helpful to choose.

The main sets of in this case tree in a present architectural photo are representing the past, the present and the future in one, symbolising respectively decay, determination (of mass and power) and prospect. It is this triangle that is useful and could be considered as a set of guiding principles of diagnosing systems in general.

The forest is characterized by its trees. In the first part, we examined the rules to which tree growth obeys, expressed in an architecture peculiar to each species, but whose principle can be identified in relation to some twenty tree models. These criteria make it possible to distinguish three sets of forest trees. The whole of the future includes young trees, who, conforming to the initial model, often regenerated, will give structure to the future forest. The whole of the present brings together the trees having reached, by an abundant reiteration and growth in thickness, their maximum biomass and which determine the current architecture of the forest; the whole present is subdivided into structural sets at different heights. Forest architecture is stratified; the relative density of the trees in each set determines the good or bad visibility of “strata.” Lastly, the whole of the past includes trees in the process of being eliminated, traces of previous structures more or less blurring the architecture of the present.

Roelof A.A. Oldeman (1974a)


Oldeman, R.A.A. (1974a, 2nd ed.). L’architecture de la forêt guyanaise. Mémoires ORSTOM, 73.

See also