Physiological mechanism of the formation of life forms of herbaceous plants and their cenoses in phylogenesis related to changes in water supply (a quantitative approach)

Amodel of phylogenetic development of life forms of herbaceous plants is proposed on the basis of a multidisciplinary study of physiological and morphological characters of complete species composition of two herbaceous cenoses (meadow and steppe). The physiological mechanism of their formation in the context of changing water supply consists in the optimization of water deficiency and production capacities of their leafs, the emergence of most efficient species-level sprout forms (non-rosette, semi-rosette and rosette), and finally in the establishment of a definite proportion between these forms within the composition of a given herbaceous cenosis.