Samaneh Sadat Mahzooni Kachapi; Pejman Tahmasebi; Ataollah Ebrahimi; Mohammad hasan Jouri; Mohsen Faal; Reza Omidipour
Abstract
Ecological processes at different scales led to heterogeneity in the landscape by changing the pattern of the landscape structure. These would result in fragmentation and disintegration of landscape structures and filtering biodiversity characteristics such as species functional diversity. We performed ...
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Ecological processes at different scales led to heterogeneity in the landscape by changing the pattern of the landscape structure. These would result in fragmentation and disintegration of landscape structures and filtering biodiversity characteristics such as species functional diversity. We performed this study to quantify the patches and classes characteristics of the landscape (metrics) and their impact on indicators of species and functional diversity. Sampling was performed in a semi-steppe rangelands of Chaharmahal and Bakhtiari, where the natural structure of the landscape creates various patches such that classified in seven different classes of plant communities. In each class, different patches were randomly selected and within them 5 to 10 macroplots of 30 * 30 m were randomly-systematically established. Afterwards, 3 plots of 2 * 2 m2 installed in macroplots in order to sample canopy cover and number of species. Taxonomic, functional diversity and functional beta diversity indices were measured using "Vegan", "FD" and "betapart" statistical packages in R software, respectively. The landscape metrics were also measured using Fragstats software. Finally, the relationships between diversity indices and landscape metrics were analyzed using linear regression. The results at the patch level showed a significant negative relationship between the shape and functional diversity indices such as leaf nitrogen weight average and leaf specific surface area weight average. The results at the class level indicate the positive effect of the functional evenness index on the edge density metric as well as the functional beta diversity of the patch richness metric.
moslem yazdani; reza erfanzadeh; Asghar Mosleh Arani
Abstract
Study of the effect of woody plant species on the production, diversity and richness of substratum herbaceous species, especially in the arid and semiarid regions, is essential for the proper management of these ecosystems. Therefore, the rangelands of Chenarnaz region in Khatam city in Yazd province ...
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Study of the effect of woody plant species on the production, diversity and richness of substratum herbaceous species, especially in the arid and semiarid regions, is essential for the proper management of these ecosystems. Therefore, the rangelands of Chenarnaz region in Khatam city in Yazd province were selected and then, using 0.5m×0.5m quadrats, vegetation sampling was performed under the selected 15 sites from Daphne mezerum, Amygdalus scoparia and Ebenus stellate (growing in equal topographical conditions) canopies, and outside of the canopies (as control). In each quadrat, the cover percentage of each plant species was visually estimated and the productions were measured by clipping and weighing method. The species diversity and richness indices were calculated using Past software through introducing the plant covers into the software. The results showed that the most values of Shannon-Weaner and Simpson diversity indices were found under A. scoparia (2.07 and 0.80, respectively) and the lowest values were found under E. stellata (1.010 and 055, respectively). In addition, the highest values of Menhinik and Margalef richness indices were found under A. scoparia (4.90 and 3.43, respectively) and D. mezerum (4.25 and 3.12, respectively), while the highest production was found under E. stellata (64.76 g/m2). The results of this study showed that different woody species had the desired but different effects on the herbaceous species, in such, A. scoparia and D. mezerum had significant positive effects on species diversity and E. stellata increased significantly species production; therefore, conservation of all woody species is emphasized in the region.
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.