Esmaeil Sheidai Karkaj; isa jafari; roghayeh jahdi
Abstract
Fires are one of the most important factors affecting natural ecosystems. This study was done in order to investigate the effects of fire on soil chemical properties, soil seed bank and vegetation cover in Yeke Bermagh, Highland ranegelands in the southern part of Golestan National Park. After determination ...
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Fires are one of the most important factors affecting natural ecosystems. This study was done in order to investigate the effects of fire on soil chemical properties, soil seed bank and vegetation cover in Yeke Bermagh, Highland ranegelands in the southern part of Golestan National Park. After determination of control and burned area, sampling was done with 5 transects and 5 plots. Vegetation cover, density and production were recorded in each site. One plot was chosen for analysis of soil chemical properties and soil seed bank along transects. Sampling for seed soil bank determination was accomplished in two depths, 0-5 cm and 5-10 cm. In order to distinguish the differences between the two depths in each site, the independent t-test, and pair t-test were used. Comparison of soil properties in the two control and burned areas showed that pH, potassium, nitrogen, phosphors, carbon, EC and CEC in the burned area was more than control area. According to the results the amount of richness and diversity of seed bank in the control area was higher than the burned area. Furthermore, richness and diversity in the first depth was more than the second depth, in both areas.
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.
Moharram Ashrafzadeh; Reza Erfanzadeh
Abstract
This study was carried out to investigate the effect of crown canopy of Ziziphus spina-christi on seed bank characteristics (density and similarity with above ground flora) in two sites with saline-alkaline and alkaline soils. In each soil, forty plots were established, half in and half outside of Z. ...
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This study was carried out to investigate the effect of crown canopy of Ziziphus spina-christi on seed bank characteristics (density and similarity with above ground flora) in two sites with saline-alkaline and alkaline soils. In each soil, forty plots were established, half in and half outside of Z. spina-christi cover. In each plot, soil sampling was done from 0-5 and 5-10 cm depths. Paired and un-paired t-test were used to compare soil seed bank characteristics between the depths, between two different soils and between in- and outside the tree canopy. The results showed that the density of seed bank in 0-5 cm depths was significantly higher than 5-10 cm depths in both soils. The density of seed in both depths was significantly higher in saline-alkaline than alkaline soils. The similarity coefficient between soil seed bank and above-ground was significantly different between under tree canopy of two soils in 0-5 cm. Soil seed density was highest under crown cover in both soils. The crown canopy of trees in dry rangelands can play an important role in reservation of soil seed bank. Therefore, the conservation of individual trees in these areas should be concerned of the managers.
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.
