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.
Mina Bashmaghi; Reza Erfanzadeh; Mahdi Abedi
Abstract
In the current study, the variation of soil seed bank density was evaluated in two different fire severities, i.e. low and high. Soil sampling was done in Sharlegh site, Golestan national park. Therefore, 5 soil samples for both grass patches and shrub patches in each burnt and control sites were selected. ...
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In the current study, the variation of soil seed bank density was evaluated in two different fire severities, i.e. low and high. Soil sampling was done in Sharlegh site, Golestan national park. Therefore, 5 soil samples for both grass patches and shrub patches in each burnt and control sites were selected. In burnt sites, grass and shrub patches were considered as low and high fire severities, respectively. For data analysis, GLMM and T test were applied.The seed germination method was used in green house to identify soil seeds. Altough, the results of statistical R software indicated that avrage soil seed bank density in burnt-site (74.5) had no significant difference compared with unburnt-site (132.3); however, fire had significant effect on plant functional groups. The results showed that soil seed bank density of different plant functional groups were affected differently by fire severities,. Total seedlings of annual forb was increased (1785 to 3543)and decreased (5000 to 1471) in low and high fire severities, respectively. Total seedlings of pernnial grasses were significantly decreased (7114 to 842.9) in low fire severity while high fire severity had no significant effect on perennial grasses seed bank density. Fire severity had no significant influence on soil seed bank richness. Our results indicated that the surface and severity of fire should be included and interpreted in the future studies.
zahra nikbakht; Mohammad Farzam; Mohammad Khajeh Hosseini; Hamid Ejtehadi
Abstract
The study of soil seed bank provides useful information on management and restoration of natural ecosystems. In the arid environments, some perennial plants may cause accumulation of seed bank under their canopy, thereby protecting them against the livestock herbivory and the other environmental factors. ...
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The study of soil seed bank provides useful information on management and restoration of natural ecosystems. In the arid environments, some perennial plants may cause accumulation of seed bank under their canopy, thereby protecting them against the livestock herbivory and the other environmental factors. This study was conducted with objective to investigate effect of perennial plants on density of soil seeds bank, under different utilization levels in an arid steppe rangeland. Three adjacent rangeland sites were selected, i.e. intense grazing, moderate grazing and no grazing (enclosure), and three line transects were randomly located within each site. Along each transect, soil samples were taken from the depth of 0–5 cm under the canopy of perennial plants or the nearby open space. The seed bank density was determined by the technique for separating seeds from the soil. The density of soil seed bank in the moderate and intensive grazing sites was higher than in the enclosure. In addition, seed bank density under the canopy of perennial plants was significantly higher than in open space, in each of three sites. The highest and lowest seed bank density were observed under the canopy of Rosa persica and Astragalus heratensis, respectively. Generally, the results of this research indicate the key role of perennial range plants in protecting soil seed bank of other plants, under the circumstances of high livestock grazing in the arid steppe rangelands.
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.