Effects of the super absorbent polymer (SAP) were tested on both the soil attributes and growth properties of Seidlitzia rosmarinus in the arid Emrani region of Iran in a reclamation study. A SAP concentration gradient (SAP 0 ¼ SAP 0 g dm À3 , SAP 1 ¼ SAP 1 g dm À3 , and SAP 3 ¼ SAP 3 g dm À3 of soil) was coupled with 30-and 60-day irrigation intervals, and results were evaluated after two growing seasons. Results indicate that application of SAP 1 increased available water content up to 68.5% and decreased soil bulk density by 25.5% and soil infiltration rate by 21.5%. SAP enhanced growth indices and seedling establishment rates of S. rosmarinus under drought stress. In addition, the application of SAP 3 can significantly increased soil cation exchange capacity up to 31% compared to the control. This study demonstrated the increased water retention properties of SAP that leads to higher soil water storage capacity for S. rosmarinus seedlings during the first months of out-planting in arid regions. Overall, the used SAP enhanced soil and plant properties, but most assessed parameters did not differ between SAPs 1 and 3. Therefore, the 1 g application rate is recommended based on technical as well as economic considerations.

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Minimizing the impact of timber harvesting on forest stands and soils is one of the main goals of sustainable forest operation (SFO). Thus, it is necessary to make an accurate assessment of forest operations on soil that is based on the SFO perspective. The present study was conducted according to SFO principles to investigate the time required for the natural recovery of soil after disturbance by skidding operations in some Iranian forests. The physical, chemical, and biological properties of soil found in abandoned skid trails from different time periods were compared with undisturbed forest soils. The soil bulk density, the penetration resistance, and the microporosity of a 25-year-old skid trail were 8.4–27.4% and 50.4% greater, and the total porosity, macroporosity, and soil moisture were 1.9–17.1% and 4.6% lower than the undisturbed area. In a 25-year-old skid trail, the values of pH, Electrical conductivity (EC), C, N, available P, K, Ca, and Mg, earthworm density, and biomass were lower than in the undisturbed area, and the C/N ratio value was higher than in the undisturbed area. High traffic intensity and slope classes of 20–30% in a three-year-old skid trail had the greatest impact on soil properties. In order to have sustainable timber production, SFO should be developed and soil recovery time should be reduced through post-harvest management operation.

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ABSTRACT. Pastoralists' knowledge of adaptive rangeland management in Iran has long been only selectively analyzed and documented. This study attempts to rectify that by outlining the indigenous ecological knowledge of the pastoralists of Nariyan village in the Taleghan region of northern Iran, and by evaluating the influence of such knowledge on rangeland management. Local herd owners operate according to traditional herding practices; their knowledge of rangeland plants and principles of sustainable rangeland management is indigenous and is based on centuries of experience and observation. Their in-depth knowledge covers the medicinal properties of various local plant species and the palatability of the most salient forage species in terms of sustaining the sheep and goats that are their livelihood. This study investigates some of the traditional strategies of rangeland management used in the Taleghan region, the rationale and timing of livestock rotation in the rangelands, local landscape classification, and local know-how in animal husbandry, all of which are indispensable in contributing to the pastoralists' survival and maintenance of the local environment.

Evaluation of soil seed bank (SSB) in relation to biotic environmental factors could be important in degraded areas, since SSB is one of the major sources that facilitates the recovery of degraded plant communities after disturbances such as grazing, flooding and drought. The aim of this study was to investigate the role of Astragalus myriacanthus and Acantholimon spinosum on SSB characteristics. Soil sampling was carried out in four different positions (upslope edge, downslope edge, center and outside) of each cushion in semiarid mountainous regions in Iran. Then, SSB composition and density, species diversity and richness of SSB in each position were estimated using the germination method. The results of the nonmetric multidimensional scaling showed that the separation of species composition of SSB in four different positions was not possible in any of the cushion species. Nevertheless, the results indicated that the lowest of SSB density, species diversity and richness were observed in the outside of the two cushions. In both cushions, A. myriacanthus and A. spinosum, the mean SSB density (1,606.4 and 646.5 seeds/m2, respectively) was significantly higher in the upslope edge. Totally, the mean density of SSBs in A. myriacanthus (903.6 seeds/m2) was significantly higher than that of A. spinosum (360.6 seeds/m2). We concluded that the cushion plants can act as seed traps and therefore could facilitate recovery of degraded sites in the steep‐hilly areas, while, the possibility of seed penetration into the soil of different directions of cushion might be significant.

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