Different Effects of Shrubs and Trees on Seed Bank Richness and Diversity in the Understory Soil (Case Study: Kerman Province, Sharbabak)

This study aimed to investigate the effect of canopy trees and shrubs: Pistacia atlantica، Amygdalus scoparia، Amygdalus eburnean on the species diversity and richness of soil seed bank. Ten individuals of each species were selected and one quadrate was established in and outside of crown canopy of each species. In each plot، soil samples were collected from 0-5 and 5-10 cm depths. GLM was applied to assess the effect of woody species، canopy cover، and depth of sampling on the characteristics of soil seed bank. The paired t-test was used to compare the diversity and richness of soil seed banks beneath and outside the canopy. The results showed that the highest species richness of soil seed bank was related to Pistacia atlantica، 0. 24، which was significantly higher than the average species richness of soil seed banks in other species Amygdalus scoparia، Amygdalus eburnea with 0. 10 and 0. 14، respectively. Pistacia atlantica had the highest species diversity with 0. 65 compared to the two other species Amygdalus scoparia and Amygdalus eburnean with 0. 48، 0. 53، respectively. Paired t-test results showed that canopy of woody species significantly increased soil seed bank diversity and richness beneath their canopy. Our results indicated that canopy of tree and shrub species in arid region affected positively on soil seed bank preservation.