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.