parisa niknam; Reza Erfanzadeh
Abstract
In this study, the effect of cushion plants on spatial distribution of soil seed bank was studied in mountainous and hilly rangelands in Vaz watershed, Mazandaran province. Therefore, we selected randomly 20 Onobrychis cornuta individuals and sampled from soil at four positions around each individual ...
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In this study, the effect of cushion plants on spatial distribution of soil seed bank was studied in mountainous and hilly rangelands in Vaz watershed, Mazandaran province. Therefore, we selected randomly 20 Onobrychis cornuta individuals and sampled from soil at four positions around each individual (upslope, downslope, center and, outside as control). Soil samples spread out under natural conditions in greenhouse to germinate the seeds. Germinated seeds were identified then, the seed density per square meter and species richness were calculated and both of them were compared between the four sampling positions. Two and one-way ANOVA, T-test and Duncan test were used to compare the effect of location, depth and their interaction on soil seed bank characteristics. The results showed that the effect of the location and depth of the density and species richness at level of 0.01% were significant. The results of Duncan test showed that seed density in the upslope and center positions (average 5473 and 4099.5 seed/m2, respectively) was significantly higher than seed density in the downslope and outside positions (average 2685.5 and 2413.8 seed/m2, respectively). Similarly, species richness in the upslope and center positions (the average 9.7 and 9.5, respectively) was significantly higher than species richness in the downslope and outside positions (average 7 and 6.4, respectively). Density and species richness of soil seed bank at depth of 0-5cm was significantly greater than the depth of 5-10cm. This study clarified the positive significant effect of canopy of cushion plants on seed density and richness.
Paria Kamali; Reza Erfanzadeh; Hasan Ghelichnia
Abstract
This study aimed to investigate the effect of animal grazing on soil seed bank characteristics in the northern slopes of Alborz. For this purpose, soil seed bank characteristics were compared between grazed and ungrazed areas. Therefore, four transects perpendicular to the sides of exclosure inside and ...
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This study aimed to investigate the effect of animal grazing on soil seed bank characteristics in the northern slopes of Alborz. For this purpose, soil seed bank characteristics were compared between grazed and ungrazed areas. Therefore, four transects perpendicular to the sides of exclosure inside and outside of it were established. Then soil samples were collected within 28 plots inside and 28 plots outside of exclosure along the transects from two different depth: 0-5 and 5-10 cm. Soil samples were then spread in the greenhouse and the plant species germinated in the greenhouse were identified and removed one time per 12 days. General linear model and factorial was used to study on the effect of grazing, depth and interaction between grazing and depth on soil seed bank characteristics. In case that the interactions became significant, unpaired t-test was used to compared seed bank characteristics between grazed and ungrazed in each depth, separately. In addition, paired t-test was applied to compare seed bank characteristics between two depths in grazed and ungrazed areas, separately. The results showed that all seed bank characteristics were significantly higher in ungrazed than grazed area particularly in upper layer of soil. All seed bank characteristics were also significantly higher in upper layer than the deeper layer of soil. The results implied that soil seed bank is a reliable source to recover the over grazed degraded points in the study area.
