Abstract
Plants growing in arid environments developed structural adaptations to reduce water loss and dissipate excessive light energy. However, such adaptations as thick cuticle, sunken stomata, developed mechanical tissue, and trichomes, may have various functions and can also be found in plants growing in mesic environments. To better understand the role of xeromorphic adaptations, it is important to study plants of the same species from different habitats. The object of our study was Gymnospermium altaicum (Pall.), a small perennial plant having the status of a rare species for Kazakhstan. For anatomical and morphometric studies, plants were sampled from three populations with different moisture regimes. Populations 1 and 3 were growing in drier conditions, on south-east and north-east slopes, respectively, while population 2 was found on a north-facing slope receiving more rainfall. We demonstrate, for the first time, that anatomical features and morphometric parameters of G. altaicum are correlated to the humidity variations. The xeromorphic features of vegetative organs of plants from populations 1 and 3 were not observed in plants from population 2. The outcomes of this research will help us to better understand the adaptive potential of G. altaicum and develop effective conservation strategies for its wild populations.