Functional differences in leaves and carbon-assimilating tissues between steppe and forest plants in the Altai Mountains

Abstract

The quantitative traits of the leaf mesophyll were studied for 31 steppe and forest plant species belonging to 21 families in the Altai Mountains at an altitude of 1600-2150 m above sea level. Herbaceous perennials predominated among the studied species. The studied species had an isopalisade, homogeneous and dorsoventral type of leaf meso-phyll structure. Among the species of the forest zone, the dorsoventral type of leaf structure prevailed, in the steppe zone the proportion of species with dorsoventral mesophyll is lower due to the appearance of succulents and species with an isopalisade structure of leaf mesophyll. The species of the forest belt were distinguished low leaf density by larger mesophyll cells and their low number per unit of leaf area compared to steppe plants. As a result the integral leaf mesophyll parameters of the steppe belt species - the number of chloroplasts and the total surface of chloroplasts per unit area of the leaf had higher values compared to the forest belt. It is concluded that the integral parameters of the mesophyll of the leaf strictly correspond to the conditions of species growth.