The paper discusses the results of multiannual investigations of metabolic processes and patterns of the structural formation in pine. The objects were individual trees in middle-aged pine stands of various productivity. Pine is shown to possess a balanced structure of the transport system. Strict linear relationships exist between the area of cross-sections of different organs. The transport system performs a regulatory function in the source-sink relationships at the whole plant level. The dynamics of carbohydrate distribution among pine organs was investigated, revealing a stable dynamics of carbohydrate concentrations under different ecological conditions. The gas exchange dynamics is related to the direction of the source-sink interactions in accord with the intensity of growth processes and ambient conditions. Carbon cycle parameters, carbon influx to the tree layer and carbon budget in a pine forest were calculated. Data on the amounts of moisture consumption by pine are reported. Major parameters influencing the water exchange dynamics were determined. Many parameters of the metabolic processes investigated (mean annual moisture consumption, photosynthetic production per unit needle weight, assimilate concentration in tree tissues) were invariant. Pine adapts to new stress-induced conditions via structural adaptations rather than by modifying its functions.