Belowground bud banks are essential for the regeneration of plant population in arid desert areas, and their response to environmental changes could reflect adaptive strategies of plants to desert habitats. However, the size and composition of belowground bud banks and their response to environmental factors in the desert steppe zone remain poorly understood, challenging desertification control efforts in arid desert areas. This study examined the density and vertical distribution of horizontal and vertical rhizome buds of a rhizomatous legume herb Sophora alopecuroides L., its population characteristics, and soil physical-chemical properties in three habitats (interdune lowland (IL), flat sandy land (FSL), and desert steppe (DS)) in a desert steppe zone, northern China. Our findings revealed that: (1) total and horizontal rhizome bud densities of S. alopecuroides differed significantly among the three habitats ( P <0.05), with the largest total rhizome bud density (177 buds/m 2 ) in IL and the smallest (63 buds/m 2 ) in DS; ( 2 ) horizontal rhizome buds distributed in the deep soil layer were dominant in IL, while vertical rhizome buds in the top soil layer were predominant in DS; and (3) soil coarse sand, nutrient content, and population density were the primary factors affecting bud bank density of S. alopecuroides . Specifically, horizontal rhizome buds were dependent largely on soil coarse sand content, and vertical rhizome buds tended to be more related to soil organic matter content and population density. Our results indicated that horizontal rhizome buds were more important in IL with frequent aeolian disturbance, whereas vertical rhizome buds were more important in DS with abundant water and nutrient resources. The plastic responses and survival strategies of S. alopecuroides bud bank to different habitats provide valuable information for the effective implementation of desertification control measures and the management of desert steppe ecosystems.
Dongmei et al. (Thu,) studied this question.