Sajad Amiri; reza erfanzadeh; yahya esmaeil pour; reza omidipour
Volume 23, Issue 3 , January 2017, , Pages 645-660
Abstract
This research was aimed to study the effects of elevation and aspect on diversity components (alpha, beta and gamma) using additive partitioning in the Geno Mountain. All plant species were listed in nine elevation zones (400-1050 m a.s.l.) in southern and eastern aspects of Geno. The cover percentage ...
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This research was aimed to study the effects of elevation and aspect on diversity components (alpha, beta and gamma) using additive partitioning in the Geno Mountain. All plant species were listed in nine elevation zones (400-1050 m a.s.l.) in southern and eastern aspects of Geno. The cover percentage was measured using five plots of 4m2 (in total 90 plots) in each elevation zone. Total plant species diversity (γr) was partitioned into additive components within plots (α1) and between plots (β1) and among elevation zones (β2) and among aspects (β3). The results showed that β3 diversity (72.36%) and β1 (8.19%) had the highest and lowest contribution to the total diversity (γr), respectively. The β3 and α1 values were higher and lower than the expected values, respectively, indicating the non-random distribution of plant species. The lowest observed percentage and expected values at the alpha level were recorded for both southern and eastern directions. In addition, the lowest observed values at the alpha level were recorded for the southern (5.95%) and eastern (5.73%) directions. Generally, beta components had a higher percentage, whose values were higher than that of the expected values. On the other hand, the alpha component in eastern and southern directions was lower than expected values. The results showed that the highest Shannon index (1.72) and richness (22) were obtained at elevations of 1200-1600 m a.s.l. and 1600-2050 m a.s.l, respectively.According to the results of this study, it is suggested that the regional scale (whole area) should be taken into consideration to protect and enhance the diversity.
Elham Fakhimi Abarghoie; Mansoor Mesdaghi; Parviz Gholami; Hosein Naderi Nasrabad
Volume 18, Issue 3 , September 2011, , Pages 408-419
Abstract
One of the main objectives of ecosystem managements is preservation of diversity. By measuring the diversity and evenness of the species, the necessary management recommendations will be presented. In this research, the effect of slope, aspect and elevation on richness and evenness of plant species were ...
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One of the main objectives of ecosystem managements is preservation of diversity. By measuring the diversity and evenness of the species, the necessary management recommendations will be presented. In this research, the effect of slope, aspect and elevation on richness and evenness of plant species were evaluated at steppe rangelands of Nodushan, in Yazd province. Systematic random sampling method was applied and the size of plot was determined by minimal area. The results showed that elevation had significant effects on diversity and frequency of species and moderate elevation ranges of 2400- 2600 had higher richness and evenness. Slope range had also significant effects on diversity and frequency and high slopes (30- 50%), had the highest diversity. Aspects had no significant effects on indices of diversity.