Plant-soil interactions change vegetation allocation strategy and biodiversity under various coastal reclamation patterns

Despite plant-soil interactions being able to influence the functional characteristics of vegetation, it remains unclear whether and how the effects of different coastal reclamation patterns on plant-soil interactions would change vegetation allocation strategies and biodiversity.

This study evaluated the vegetation characteristics, soil quality, and plant-soil interactions in three different types of wetlands: a natural coastal wetland (NCW), a reclaimed wetland with sea embankments on a native wetland (SEW), and a reclaimed wetland formed through land reclamation from the sea (LRW).

The findings indicated that different reclamation patterns significantly impacted the ecological characteristics of Spartina alterniflora and Phragmites australis communities in coastal wetlands (P < 0.05), while Suaeda salsa communities were insensitive to reclamation. Reclamation activities improved the integrated soil quality index by 5% in SEW and 27% in LRW. Notably, enhancing soil quality may boost above ground biomass allocation while reducing biodiversity. Additionally, plant-soil interactions in reclaimed wetlands showed light incoordination, with the higher coordination degree potentially promoting root allocation and biodiversity.

Coastal reclamation impacts plant-soil interactions, varying by reclamation patterns and community types. In the future restoration and management of reclaimed wetlands, zoned management should be implemented according to different types of plant communities, with appropriate thinning and replanting of native species based on the plants growth status to promote species diversity. Moreover, management practices such as improving soil aeration and inoculating beneficial microbial formulations are recommended to enhance coordinated plant-soil interactions.