Research on Soil Seed Bank Characteristics of Medicinal Plant Communities in Yangxian, Shaanxi

Using the germination method, we researched soil seed bank composition, density, species richness, and similarity with aboveground vegetation structures in medicinal plant communities of Yangxian, Shaanxi, China. Results showed that: 50 plant species belonging to 28 families and 47 genera were recorded, and included 45 herbs, 5 arbors, and 21 medicinal plants. Soil seed density showed significant differences among the soil seed banks of the medicinal plant communities, which were, from high to low, 2-year-old Magnolia officinalis Rehd. et Wils. subsp. biloba (Rehd. et Wils.) Law, 4-year-old M. officinalis Rehd. et Wils. subsp. biloba (Rehd. et Wils.) Law, 7-year-old M. officinalis Rehd. et Wils. subsp. biloba (Rehd. et Wils.) Law, 11-year-old M. officinalis Rehd. et Wils. subsp. biloba (Rehd. et Wils.) Law,Eucommia ulmoides Oliver-M. officinalis Rehd. et Wils. subsp. biloba (Rehd. et Wils.) Law, 7-year-old Magnolia officinalis Rehd. et Wils., E. ulmoides, Macrocarpium officinale Sieb. et Zucc., and M. officinale-M. officinalis Rehd. et Wils. subsp. biloba (Rehd. et Wils.) Law. Soil seeds exhibited surface accumulation. Soil depth was negatively correlated with the number of seeds. The similarity between the soil seed bank and aboveground vegetation structures was generally low. Soil seed bank density was higher for younger forest communities than for older forest communities, indicating that younger communities have higher potential value in regards to natural forest regeneration and biodiversity conservation. This study provides theoretical guidance for the natural regeneration of medicinal plant communities in Yangxian，China.