| Abstrakt: |
Background and Objectives Flood 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. Methodology In 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. Results The 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 floodfree 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. Conclusion The 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. [ABSTRACT FROM AUTHOR] |
