Shahin Aghamirzadeh; Hamzeh Saeedian; Peyman Madanchi; Alijan Abkar
Volume 31, Issue 2 , August 2024, , Pages 169-185
Abstract
Background and ObjectivesFlood spreading has emerged as one of the most important management strategies for soil and water resources in arid and semi-arid areas, gaining attention from researchers worldwide in recent decades. This technique has been implemented in various watersheds globally to ...
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Background and ObjectivesFlood spreading has emerged as one of the most important management strategies for soil and water resources in arid and semi-arid areas, gaining attention from researchers worldwide in recent decades. This technique has been implemented in various watersheds globally to address the critical issue of moisture scarcity, which is a significant factor limiting plant growth in these regions. The flood spreading system not only supplies moisture for plants but also helps recharge underground aquifers, making it one of the most innovative methods developed for water management in arid and semi-arid environments. By effectively utilizing floodwaters that would otherwise be lost, flood spreading offers a viable solution for enhancing water resources and supporting sustainable agricultural practices in these challenging landscapes. MethodologyIn this study, we investigated vegetation density, regeneration, trends, and the condition of rangelands at the Abbarik Bam flood spreading station. To assess the effect of flood spreading on vegetation cover, we identified the site with the most flooding, located away from tree cover, and established four transects, each 100 meters long and spaced 15 meters apart, parallel to the distribution channels. Ten plots were installed along each transect, with a distance of 10 meters between them. At the end of the one-year period, we compared the collected data to accurately assess the changes in the flood spreading environment relative to a control environment, both of which were selected for grazing exclusion. This comparison allowed for an informed evaluation of the effects of flood spreading on vegetation density in the area. The experiment was conducted using a split-plot design in a randomized complete block format with four replications. The main plots included flooded, non-flooded, and control areas, while the subplots encompassed five vegetative forms: perennial grasses, perennial forbs, annual grasses, annual forbs, and density parameters were recorded. ResultsThe results also revealed that the density of forb plants was 2.6 times higher in flood-free plots and 4.2 times higher in flooded plots compared to the control area. In contrast, the density of perennial grasses was 0.1 times lower in flood-free plots and 0.05 times lower in flooded plots than the control area. The density of perennial broadleaf plants was 1.7 times higher in both flood-free and flooded plots compared to the control area. Interestingly, the density of annual grasses was 30.78 times higher in flood-free plots and 6.3 times higher in flooded plots than the control area. Finally, the density of annual broadleaf plants was 2.4 times higher in flood-free plots and 5.1 times higher in flooded plots compared to the control area. ConclusionThe results indicated that the highest average vegetation density in flood-free plots was associated with the annual grasses, followed closely by annual broadleaf plants. In the control plots, the highest average vegetation density was found in annual broadleaf plants, followed by perennial grasses. Additionally, the impact of vegetative form on vegetation density was greatest for annual wheat and annual broadleaf plants, while shrub plants exhibited the lowest density. Therefore, the observed differences in vegetation cover between flooded and flood-free areas in the study region may be attributed to factors such as moisture content, nutrient availability, the accumulation of fine-grained sediments, root and bud choking, and reduced soil permeability.
Zainab Jafarian jelodar; Hosein Arzani
Volume 16, Issue 3 , December 2009, , Pages 317-328
Abstract
Plant species have important role in other organisms life circle. High diversity of plant species cause equilibrium and stability of this circle, so conservation of plant species is essential for continuity and survival of ecosystems. In this study vegetation species diversity and flora in four sub watersheds ...
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Plant species have important role in other organisms life circle. High diversity of plant species cause equilibrium and stability of this circle, so conservation of plant species is essential for continuity and survival of ecosystems. In this study vegetation species diversity and flora in four sub watersheds of Armoot, Kash, Zidasht and kalanak in Taleghan region with 16320 hectares area were studied. Thirteen vegetation types were recognized in the study area. One key area was selected in each vegetation types (in some of the vegetation types because of vast area and non –homogeneity vegetation, two key areas were selected). Two 100 meter transects were located in each key area, along each transect, 10, one meter square quadrates were located. List of species and number of species were recorded for each quadrates. Then diversity indices, species richness and evenness indices were calculated. Simpson diversity index and Shanon– Wiener diversity index were obtained 0.114 and 2.81 respectively which indicate relatively high species diversity in the study area. Species evenness based on studied indices was estimated. Richness of species was 116 with 18 families and 63 genus in rangelands of the study area.