Document Type : Research Paper


1 Msc Student of Range Management, Natural Resources and Environment Faculty, Ferdowsi University of Mashhad, Iran

2 Professor of Natural Resources and Environment Faculty, Ferdowsi University of Mashhad, Iran

3 Professor, Faculty of Natural Resources, University of Tehran, Iran


Soil erosion is a main hazard in most area of the country specially in arid and semi-arid regions and it
is very important because of sedimentation, pollution, increased flooding and its negative effects on
soil productivity. One of the features of arid and semi-arid areas is the presence of low cover of
vascular plants. These empty spaces are usually good niches for biological soil crusts or cryptogams
like mosses. These crusts contribute to a variety of ecological functions and have different effects on
soil features and vascular plants. The present study was carried out in the rangelands of Torogh dam
basin of Khorasan- Razavi province in order to find the effects of such kind of plants (mosses) on
water erosion. For this purpose, artificial runoff streams in plots with two intensity (low and high) for
30 minutes. In order to study the effects of different amount of mosses on sedimentation and specific
erosion, four different density of mosses in the same experimental situation were studied: high (60-
75% of plot), medium (35-50% of plot), low (10-20% of plot) and control (0%). The results of
analysis of variance and tukey method by the use of Minitab software showed a significant difference
in 95% level between the four considered density of mosses and the two intensity of water. As mosses
density decrease, sedimentation and specific erosion increased consequently. But there were no
significant differences in infiltration between the different treatments.