Distribution pattern and influencing factors of vegetation carbon storage of Tamarix chinense in the coastal wetland of Laizhou Bay, China

Abstract

The tamarisk shrub wetland located at the south of Laizhou Bay is the largest tamarisk area existing in the northern China, which is also the important part of the wetland ecological rehabilitation project 'Southern Mangrove Northern Tamarisk' in China. Based on the field data from Changyi National Marine Ecological Special Reserve surveyed in August 2014, we investigated the spatial patterns of vegetation, biomass, carbon content, and the associated environmental parameters in this area. The results showed that the average vegetation biomass and carbon storage were 949.0 g·m-2 and 393.1 g·m-2, respectively. They were higher in the central area than in the eastern and the western parts, and were generally the highest for the shrub part aboveground, followed by that underground, and the lowest for the litter. There were two single-species communities (dominated by Tamarix chinensis and Suaeda salsa, respectively) and four mixed communities. The carbon storage was the highest for the T. chinensis community, followed by the mixed communities and the lowest for S. salsa community. The water content and conductivity of surface soil in this area were generally low, probably due to the reduced intertidal waves blocked by the dam in the north. The vegetation carbon storage was most influenced by soil nutrients (total nitrogen and total phosphorus) and silt particle content rather than salinity. Furthermore, the alteration of the soil hydrologic condition caused the succession of vegetation communities in this area. When the salt tolerance community (e.g., S. salsa) shifted to the light salt tolerance community (e.g., Setaria viridis, Artemisia capillaries), the vegetation carbon storage increased significantly.