Estimating the potential of seed production and dispersal in mountain grassland of central Alborz (Case study: rangelands of Sorkh-Abad Savadkooh, Mazandaran province)

Seed production and dispersal are important topics in grassland management as they influence the vegetation structure and dynamics. To understand and better interpretation of changes in vegetation, it needs to identify the species composition in other sources such as the soil seed bank and seed rain. The aim of this study was to estimate the potential of seed production and seed dispersal in Sorkh-Abad grassland in SavadKoh, Mazandaran province. During growing season, mature seeds of the plants were collected and then identified and counted in laboratory. For these seeds, some properties were determined such as seed shape, seed weight, and germination percentage and seed color. Seed dispersal (seed rain) was sampled in seed traps, made by small plastic pots. During growing season, in three times, these seed traps were collected and all seeds were identified and counted. Results showed that18 species were in seed production and 17 species in seeds dispersal. The average amount of seed production was 296 seeds per square meter of which 25% belonged to Germaineae. The potential of seed dispersal was 275 seeds per square meter. Most collected seeds were light and small with elongated shape and bright colors. Stachys byzanthina, Marrubium vulgare, Descurainia sophia and Medicago lupulina comprise 45% of the seed production. Similarly, the 46% of the seed dispersal was made by Stachys byzanthina, Plantago lanceolata, Descurainia sophia and Medicago lupulina. Small numbers of species in standing vegetation were found in seed production and seed rain of this grassland.