淹水深度对黄河三角洲湿地物种多样性和生产力的影响

Effect of Inundation Depth on Species richness and Biomass in the Yellow River Delta Wetland

由于气候变化和人类活动的双重压力,湿地生态系统退化逐渐加剧。生态补水作为修复湿地的重要措施,对湿地生态系统保护与修复起到了促进作用。该措施会使湿地呈现不同的淹水深度,进而改变植物群落的组成、分布以及生物量。为了解不同淹水深度对物种多样性和植物生物量的影响,我们以黄河三角洲湿地为研究对象,通过野外原位模拟不同淹水深度实验(对照、淹水0 cm、淹水5 cm、淹水10 cm、淹水20 cm、淹水30 cm、淹水40 cm),发现淹水深度显著降低了物种丰富度;在淹水处理中,淹水0 cm的物种丰富度最高,而淹水5—40 cm物种丰富度无显著差异。另外,淹水深度增加了地上总生物量和地下总生物量,且地下总生物量占比显著高于地上总生物量。此外,淹水深度显著增加了粗根和细根生物量,且细根生物量随着土壤深度的增加而逐渐减少。以上结果可为黄河三角洲湿地的管理优化和修复提供一定的参考价值。

The degradation of wetland ecosystem has gradually intensified due to the climate change and human activities.As an important measure for wetland restoration,ecological water replenishment is beneficial to protection and restoration of the wetland ecosystem,which result in different inundation depth in the wetland,and further alter the composition,distribution and biomass of plant communities.In order to understand the impact of different inundation depths on species diversity and plant biomass,a field inundation depth manipulation experiment(no inundation,i.e.only natural precipitation;0 cm,water-saturated;5 cm,10 cm,20 cm,30 cm and 40 cm inundation depth)was conducted in the Yellow River Delta wetland,China.The result showed that inundation depth significantly reduced the species richness;the species richness was the highest under 0 cm among the inundation treatment,while there was no significant difference in species richness from 5-40 cm.In addition,inundation depth increased the aboveground and belowground biomass of plants.The fine roots gradually decreased with the increase of soil depth.Our results can provide a certain reference value for the management optimization and restoration of the Yellow River Delta wetland.