Document Type : Research Paper
Authors
1 Assistant Professor, Research Center for Agriculture and Natural Resources, Kashan Botanical Garden, Isfahan, Iran
2 Assistant Professor, Range Research Division, Research institute of Forests and Rangelands, Tehran, Iran
Abstract
This research was aimed to study the autecology of Asthenatherum forsskalii as a desert and range species (Vahl) Nevski in arid and super-arid deserts of Masileh, Isfahan province. This range species is psammophyte and belongs to the Poaceae family with numerous aerial branches growing in desert sandy dunes. In order to study the autecology of this species, its habitats in the desert sandy dunes of Aran & Bidgol were determined. After determining the habitats, ecological characteristics such as elevation range, topography, climate, soil, companion species, presence in the vegetation cover, root system, phenology and propagation of the mentioned species were all studied. Results showed that the habitats were distributed in the form of spots scattered across the sandy plains and slopes of active sand dunes. This desert plant grows in an altitude range of 780 to 1150 meters above sea level with an average annual rainfall fluctuating between 80 and 120 mm. Its mean annual temperature is about 19.1 °C. This plant is widespread on light-textured sandy soils with pH and EC (Electrical conductivity) of 7.5-8.5 and 0.34-5.1 ds/m, respectively. A. forsskalii has a fibrous root system with a length over 6 meters. All its fibrous roots are covered with sand particles. Average canopy cover is 4.2%.Average density is 11,875 to 32,500 species per hectare and it has a frequency of about 72%.Vegetative growth begins in late February and its inflorescence emerges in the second half of May and the seeds appear in late June. Summer dormancy starts from late July and continues up to mid-September. Revival of the species is possible via seeds and formation of adventitious roots in the basal area. The most important companion species in the habitats of A. forsskalii are grasslands of Cyperus eremicus and various species of genus Calligonum L.. According to the results, A. forsskalii is a psammophyte desert species which in addition to soil conservation and stabilization in sand dunes, plays an important role in providing required forage for livestock in winter rangelands.
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