The Effect of Tortella tortuosa (Hedw.) Limpr Moss on Germination of Five Dominant Grass Species in Rangelands of Golestan National Park

Biological soil crusts greatly affect the surface properties of the soil, which in turn may also alter the germination of the seeds of vascular plants. The aim of this study was to investigate the effect of moss on germination of five dominant species of Golestan National Park. At the beginning of the experiment, the seeds of five dominant plant species: Avena barbata, Bromus tectorum, Melica ciliata, Stipa caucasica and Taeniatherum caput-medusae were collected in the field and three different treatments: live moss, dead moss and control on percentage and germination rate of these seeds were investigated in five replications. In order to determine the most important factor affecting the percentage and speed of germination, the General linear mixed model and comparison of the mean were done using Tukey test. The results showed that germination percentage of B.tectorum and M.ciliata were not significantly different between different treatments but germination percentage of S.caucasica, A.barbata and T.caput-medusa among different treatments have significant differences. In all three species, the percentage of germination on the moss treatment was significantly increased. The mean germination speed of A.barbata, B.tectorum, M.ciliata, S.caucasica and T caput-medusa species were 5.87, 3.38, 2.16, 22.01 and 6.20 respectively, and only S.caucasica species among different treatments was a significant difference.