How do cryptogams affect vascular plant establishment?

摘要

There are many conflicting reports regarding the effects of cryptogamic biological soil crusts on seed germination, seedling emergence and plant establishment. The current research investigated the effects of cryptogams (mosses and lichens) on seedling emergence and initial establishment of two vascular plants, namely Stipa barbata and S. capensis, under greenhouse conditions. For this purpose, 28 cylindrical pots were used to carefully transport field soil to the greenhouse, from two adjacent areas with similar conditions with and without cryptogams in the northeast of Golestan province of Iran. For S. barbata and S. capensis seeds planted in pots, seedling emergence, establishment and performance were evaluated over two months. The rate and percentage were higher for plants, particularly S. capensis, on soils with cryptogams than those on soils without cryptogams; such improvements could be related to the effects of cryptogams on moisture, temperature and nutrient increase in soil.