School of Ecological and Environmental Sciences, East China Normal University, Shanghai, China.
Key Laboratory of Urbanization and Ecological Restoration of Shanghai, East China Normal University, Shanghai, China.
Ecol Appl. 2024 Jan;34(1):e2754. doi: 10.1002/eap.2754. Epub 2022 Dec 20.
The coastal wetland is easily invaded by alien species due to locating in the land and sea transitional area. As a potential driving regeneration force, the soil seed bank is vital to the community restoration and species diversity protection. To reveal the long-term Spartina alterniflora invasion impact on the soil seed banks and regenerated communities, we investigated the seed banks under the different vegetation types (S. alterniflora, Phragmites australis, Scirpus mariqueter, ruderal and unvegetated site) and soil depths (0-5 and 5-10 cm) in the coastal salt marsh wetland, Chongming island, eastern China. The results showed that the soil seed bank richness and species density under different vegetation types were higher than the aboveground vegetation, and those of 0-5 cm seed banks were higher than 5-10 cm, except for the unvegetated site. The species richness and S. alterniflora seed proportion in the seed banks under S. alterniflora communities (S.AS) were lower and larger respectively than those of other sites. The species composition between S.AS and the aboveground communities showed high similarity with aggregation phylogenetic structures in two soil depths. The seed bank variations at 0-5 and 5-10 cm depths were interpreted 3.03% and 2.25% by the aboveground communities, while 4.92% and 5.55% were interpreted by the soil microbial biomass. The SEM model explained 98.1% and 91.8% of the seed banks richness at the 0-5 cm depth and 5-10 cm depth, respectively, and explained 98.8% and 46.1% of the seed banks species density at the 0-5 cm depth and 5-10 cm depth, respectively. The aboveground vegetation biomass and abundance directly affected the 0-5 cm seed banks richness and species density, while its height and biomass only affected the 5-10 cm seed banks species density. The 0-10 cm soil depth microbial biomass indirectly affected the 0-5 cm seed banks richness and species density, while affected the 5-10 cm seed banks richness. Soil physical and chemical properties only indirectly affected the 0-5 cm seed banks species density. The results provided a reference for the ecological evaluation of the impacts of S. alterniflora invasion into the coastal salt marsh wetland of eastern China, and guidance for the protection and restoration of the native plant communities.
滨海湿地由于位于陆海过渡地带，容易受到外来物种的入侵。土壤种子库作为潜在的驱动再生力量，对群落恢复和物种多样性保护至关重要。为了揭示互花米草入侵对土壤种子库和再生群落的长期影响，我们调查了中国东部崇明岛沿海盐沼湿地不同植被类型（互花米草、芦苇、海三棱藨草、杂草和无植被地）和土壤深度（0-5 和 5-10cm）下的种子库。结果表明，不同植被类型下的土壤种子库丰富度和物种密度高于地上植被，0-5cm 种子库的丰富度和密度高于 5-10cm 种子库，除了无植被地。互花米草群落（S.AS）下的种子库物种丰富度和互花米草种子比例较低，而互花米草种子比例较大。0-5 和 5-10cm 土层的种子库变化分别由地上群落解释 3.03%和 2.25%，而由土壤微生物生物量解释 4.92%和 5.55%。SEM 模型分别解释了 0-5cm 土层和 5-10cm 土层种子库丰富度的 98.1%和 91.8%，解释了 0-5cm 土层和 5-10cm 土层种子库物种密度的 98.8%和 46.1%。地上植被生物量和丰度直接影响 0-5cm 种子库的丰富度和物种密度，而地上植被的高度和生物量仅影响 5-10cm 种子库的物种密度。0-10cm 土壤深度的微生物生物量间接影响 0-5cm 种子库的丰富度和物种密度，而直接影响 5-10cm 种子库的丰富度。土壤理化性质仅间接影响 0-5cm 种子库的物种密度。本研究结果为评估互花米草入侵对中国东部沿海盐沼湿地的影响提供了参考，为保护和恢复本地植物群落提供了指导。
