盐城潮滩湿地不同植被带土壤有机质空间分布特征

摘要

对盐城潮滩湿地不同植被带土壤有机质质量分数进行分析,以探讨土壤有机质的空间分布特征及其影响因素.结果表明:1)盐城潮滩湿地土壤有机质质量分数较低.介于2.97～12.92 g·kg-1.2)在水平方向上土壤有机质质量分数,植被带高于光滩,互花米草滩高于碱蓬滩与禾草滩.且各植被带之间差异显著(P＜0.05).3)在垂向上,潮滩湿地各植被带土壤有机质分布均表现为自地表向下逐渐降低的趋势;互花米草引种地土壤有机质质量分数自地表向下呈泥-沙交互分布.4)向海方向新扩张形成的互花米草种群,土壤有机质质量分数每年在表层沉积物中的累积速率为1.77 g·kg-1.5)不同植被带,植被的生物量与土壤有机质质量分数之间显著正相关(P＜0.05);同一植被带,植被的定居年数与土壤有机质质量分数之间显著正相关(P＜0.05);物源、植被类型与植被定居时问是影响潮滩土壤有机质空间分布特征的重要因素.%The contents of soil organic metter in top (0～20 cm) and core (0～70 cm) samples were analyzed in order to study the spatial distributions of soil organic matter and their ifluence factors in different vegetation zones of the Yancheng tidal flat. It has been revealed that: 1) the content of soil organic matter in the Yancheng tidal flat of Jiangsu Province is low, generally ranging between 2.97～ 12.92 g 9 kg-1 ;2) laterally, the content of soil organic matte is higher in the vegetation zones and the Spartina alterniflora flat than in the barren flat, the Suaeda salsa flat, and the grass flat, and shows significant differences (P＜0.05) among vegetation zones; 3) downward from the surface the soil organic matter tends to decrease in all vegetation zones and shows a mud-sand alternative distribution pattern at the earliest introducing area of Spartina alterniflora flat; 4) the accumulation rate of soil organic matter is 1.77 g 9 kg-1 per year in the surface sediments in the area where new population of Spartina alterniflora forms toward the sea; 5) the content of soil organic matter shows a distinct positive eororelation (P＜0.05) to the vegetation biomass in different vegetation zones and to the vegetation growth age in the same vegetation zone.Therefore, the material sources, the vegetation types and the vegetation establishment time are the important factors that influence the spatial distributions of soil organic matter in the tidal flat.