Spatial Root Distribution Patterns and Competition in Acantholimon and Astragalus Species in the Rangelands of Shanjan, Shabestar Using Python Software

Subject Areas :

Meysam alizadeh ¹ , Ghasem Habibi ^{2 *}

1 - Graduate, Department of Agriculture, Shabestar Branch, Islamic Azad University, Shabestar, Iran
2 - Associate Professor, Department of Agriculture, Shabestar Branch, Islamic Azad University, Shabestar, Iran.*Corresponding Author's Email Address: [e-mail]

Received: 2024-12-18 Accepted : 2025-05-15 Published : 2025-03-17

Keywords: Acantholimon , Astragalus, Python software, Root competition, Spatial root distribution. ,

Abstract :

Root competition plays a significant role as a key factor in determining plant distribution patterns and their adaptation in rangeland ecosystems. This research aimed to investigate the effect of root competition and the spatial distribution pattern of roots of two species, Astragalus sp. and Acantholimon sp., in the Shanjan Shabestar rangelands. The main objective of this study was to analyze the root distribution in different soil layers and the effect of soil physical properties on their competition. Sampling was conducted at five different depths (0-10, 10-20, 20-30, 30-40, and 40-50 cm), and root characteristics, including the number and diameter of roots, were measured. Root competition was analyzed using the Marked Correlation Function (MCF) and the extraction of the competition index. Soil physical properties, including texture, moisture, and organic matter, were also measured. The results showed that the number of roots in both species decreased with increasing depth, especially in the 30-50 cm depths, where a decrease of more than 88% in Astragalus sp. and 81.67% in Acantholimon sp. was observed. In Astragalus sp., the highest root density was recorded in the surface layer (0-10 cm) with an average of 50 roots per unit area, while in Acantholimon sp., this value was 60. The root distribution in Astragalus sp. showed a uniform decreasing trend, but in Acantholimon sp., a sharper decrease was observed in the lower depths. The root diameter in Astragalus sp. increased with depth and reached its maximum value (1.21 mm) at the 40-50 cm depth, while in Acantholimon sp., the highest average root diameter was observed at the 0-10 cm depth (0.83 mm) and then decreased. Competition analysis showed that Acantholimon sp. had stronger root competition than Astragalus sp., especially in the surface layers where the competition index was higher. At lower depths, due to the decrease in root density and greater access to resources, the intensity of competition decreased. Furthermore, the results showed that soil texture and moisture had a significant effect on root distribution and competition intensity. In soils with heavier texture and higher moisture, root density and competition intensity increased. These findings suggest that different species adopt different root growth strategies in response to competition and resource availability in soil layers. The results of this research can be used in rangeland management, improving vegetation restoration strategies, and increasing the productivity of rangeland ecosystems, especially in arid and semi-arid regions.

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