No abstract

The equilibrium moisture contents of almond were determined using the gravimetric-static method at 15, 30, 55 and 75C for powder and 15, 55 and 75C for nut state of almond for water activity ( a w ) ranging from 0.11 to 0.87. At a given a w , the results show that the moisture content decreases with increasing temperature. The experimental sorption curves are then described by the BET, GAB, Henderson, Oswin, Smith and Halsey models. A nonlinear regression-analysis method was used to evaluate the constants of equations. The GAB model was found to be the most suitable for describing the sorption curves; the monolayer-content values for the sorption at different temperatures are calculated. Also, the isosteric heats of adsorption of water were determined as a function of moisture content from the equilibrium data at different temperatures using the Clasius-Clapeyron equation.

Shrubs are one of the most dominant plant types in semiarid ecosystems all over the world. What remains to be investigated is how soil and vegetation characteristics vary under canopy of different species of shrubs in these regions. Thus, this study aimed to compare the effect of three shrub species (Amygdalus scoparia, Ebenus stellata, and Daphne mezereum) on soil and vegetation characteristics under their canopies in semiarid rangelands in Iran for restoration purposes of degraded areas. Fifteen sites were selected in such three shrub species, which were found close to each other in each site. Soil and vegetation characteristics were measured under the shrubs, comparing with outside the shrub canopies (control). One‐way ANOVA and nonmetric dimensional scaling were used to clarify the differences of the effects of different shrub species on sub‐canopy soil and plants. The results indicated that the effect of different species of shrubs on soil properties was not equal, more pronounced by A. scoparia. Similarly, the highest value of Shannon‐Wiener diversity was recorded under A. scoparia (2.07) as compared with D. mezerum (1.76), E. stellata (1.41) (F = 32.25, p <  0.01). The highest and lowest values of Menhinick richness index were observed under A. scoparia (3.43) and E. stellata (1.46), respectively (1.41) (F = 13.30, p <  0.01). Compared with two other shrubs, a taller canopy in A. scoparia (3.50 m vs. 2.60 m and 1.83 m) probably led to greater litter input by the shrub. Different effects of different species of shrubs on sub‐canopy soil and vegetation should be considered in the restoration projects of degraded semiarid rangelands.

No abstract

Shrub encroachment (SE) has been occurring and studied worldwide over the last century. What remains to be investigated is how soil and vegetation characteristics vary under canopy of different species of shrubs for restoration goals. Thus, this study aimed to compare the effect of three shrub species (Amygdalus scoparia, Ebenus stellata, and Daphne mezereum) on soil and vegetation characteristics under their canopies in semiarid rangelands in Iran for restoration purposes of degraded areas. Fifteen sites were randomly selected in such three shrub species which were found close to each other in each site. Soil and vegetation characteristics were measured under the three shrubs, comparing with outside the shrub canopies (control). One-way ANOVA and non-metric dimensional scaling were used to clarify the differences of the effects of different shrub species on sub-canopy soil and plants. The results indicated that the effect of different species of shrubs on soil properties was not equal, more pronounced by A. scoparia. Similarly, the highest value of herbaceous Shannon-Wiener diversity index was recorded under A. scoparia (2.07) as compared with D. mezerum (1.76), E. stellata (1.41). The highest and lowest values of Menhinick richness index were observed under A. scoparia (3.43) and E. stellata (1.46), respectively. Compared with two other shrubs, a taller canopy in A. scoparia (3.50m vs. 2.60m and 1.83m) probably led to greater litter input by the shrub. Different effects of different species of shrubs on sub-canopy soil and vegetation should be considered in the restoration projects of degraded semiarid rangelands.