The interdependence between transpiration intensity and the anatomical structure of moss leaves

Abstract

The degree of anatomical differentiation of moss leaves, as well as differing biotropic conditions of these plants, served as a basis for the choice of the following species: <i>Mnium punctatum, Catharinea undulata, Funaria hygrometrica, Polytrichum juniperinum, Polytrichum piliferum</i>, and <i>Aloina rigida</i>. Different anatomical structure of severed moss leaves does not generally influence the quantity of water evaporated during a 24-hour period, while they are kept in an atmosphere of relative humidity of 85% and 95%. The differences observed in the dynamics of water loss from leaves under conditions of relative atmospheric humidity of 85% are more likely due to the properties and structure of cell walls, though they may also, result from different resistance of cytoplasm to evaporation. The process of photosynthesis exhibits a significantly greater sensitivity to variations in water content of leaf than does the process of respiration. In most of the studied species, the respiration activity decreases markedly, though it does not become completely arrested following the period of dehydration applied.