莱州湾滨海柽柳林湿地植被碳储量的分布特征及其影响因素

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

莱州湾南岸的柽柳林湿地是我国北方现存面积最大的柽柳林滨海湿地,也是我国"南红北柳"生态工程的重要组成部分.本文基于2014年8月在昌邑海洋生态特别保护区的调查资料,研究了该湿地植被生物量、碳储量的空间分布特征及其影响因素.结果表明:该湿地植被生物量为949.0 g·m^(-2),植被碳储量为393.1 g·m^(-2),基本呈中部高、东西部低的分布特征;植被各部分生物量、碳储量均表现为:地上部>地下部>凋落物.该区域主要有柽柳、碱蓬2个单优群落和4个混生群落,植被碳储量以柽柳群落最高,混生群落居中,碱蓬群落最低.受北部潮间带防潮坝的影响,表层土壤的含水量和电导率均不高,土壤盐分不是植被碳储量的主控因子,植被碳储量主要受土壤的营养盐状况(全氮和全磷)和粒径结构(粉粒含量)的影响.土壤水文条件的改变造成了植被群落的演替,在由耐盐群落(盐地碱蓬群落)向轻耐盐群落(茵陈蒿群落、狗尾草群落等)的演替过程中,植被碳储量增大.

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.