闽江口芦苇与短叶茳芏湿地土壤无机硫形态分布特征及其影响因素

选择闽江口鳝鱼滩的芦苇湿地、短叶茳芏湿地以及二者交错带湿地为对象,研究了不同类型湿地土壤无机硫赋存形态的分布特征及其主要影响因素。结果表明,芦苇与短叶茳芏在空间扩展过程中形成的交错带湿地土壤的水溶性硫(H_2O-S)、吸附性硫(Adsorbed-S)和盐酸可溶性硫(HCl-Soluble-S)含量在0—40 cm土层上整体要高于芦苇湿地和短叶茳芏湿地,而盐酸挥发性硫(HCl-Volatile-S)含量则与之相反。在垂直方向上,不同类型湿地土壤的H_2O-S、Adsorbed-S和HCl-Soluble-S含量整体均自表层向下呈先降低而后增加的变化,而盐酸挥发性硫(HCl-Volatile-S)含量则与之相反。3种类型湿地土壤中不同形态无机硫平均含量整体均表现为HCl-Soluble-S H_2O-S Adsorbed-S HCl-Volatile-S,且其总无机硫(TIS)平均含量分别占全硫(TS)含量的22.29%—39.99%(芦苇湿地)、32.39%—33.33%(交错带湿地)和30.20%—30.86%(短叶茳芏湿地)。与芦苇湿地和短叶茳芏湿地相比,交错带湿地土壤的H_2O-S、Adsorbed-S、HCl-Soluble-S和TIS平均含量整体均呈增加趋势,增幅分别为36.94%和54.31%、34.84%和13.03%、73.25%和67.59%以及45.72%和45.28%;与之不同,HCl-Volatile-S平均含量则呈降低趋势,降幅分别为2.78%和22.24%。不同类型湿地土壤中H_2O-S、Adsorbed-S和TIS含量的变化主要受有机质含量和细颗粒组成的控制,而HCl-Soluble-S和HCl-Volatile-S含量主要受土壤氧化还原环境和金属元素分布的影响。研究发现,芦苇与短叶茳芏的空间扩展明显增加了交错带湿地土壤的H_2O-S、Adsorbed-S、HCl-Soluble-S和TIS含量,但降低了HCl-Volatile-S含量,说明二者的空间扩展在整体提高交错带湿地土壤有效硫供给能力的同时,亦降低了挥发性硫化物可能对二者生长产生的不利影响,这对于保持二者在交错带湿地中的竞争力具有重要生态意义。

Distribution characteristics and influencing factors of inorganic sulfur forms in the soils of Phragmites australis marsh and Cyperus malaccensis marsh in the Min River Estuary

To investigate the distribution and major influencing factors of the inorganic sulfur forms on Phragmites australis marsh (PA), Cyperus malaccensis marsh (CM), and ecotonal marsh (P. australis-C. malaccensis marsh; PCM) in the Shanyutan tidal wetlands of the Min River Estuary. Results showed that during the spatial expansion between PA and CM, the contents of H₂O-sulfur, adsorbed-sulfur, and HCl-soluble-sulfur in the soils of PCM (0-40 cm) were generally higher than those of PA and CM; however, the values of HCl-volatile-sulfur was just in the opposite. In the vertical direction, the contents of H₂O-S, adsorbed-S, and HCl-soluble-S in different marsh soils decreased initially, followed by a subsequent increase, while the values of HCl-volatile-S was just in the opposite. The average of the different inorganic sulfur forms generally followed the order of HCl-soluble-S > H₂O-S > adsorbed-S > HCl-volatile-S. The average total inorganic sulfur (TIS) content accounted for 22.29%-39.99%, 32.39%-33.33%, and 30.20%-30.86% of the average total sulfur (TS) content in the soils of the three PA, PCM, and CM, respectively. Compared to PA and CM, the contents of H₂O-S, adsorbed-S, HCl-soluble-S, and TIS in the soils of PCM increased by 36.94% and 54.31%; 34.84% and 13.03%; 73.25% and 67.59%; and 45.72% and 45.28%, respectively, while the levels of HCl-volatile-S decreased by 2.78% and 22.24%. The contents of H₂O-S, adsorbed-S, and TIS in different marsh soils were mainly controlled by the organic matter and particle composition, whereas the values of HCl-soluble-S and HCl-volatile-S were dependent on the oxidation-reduction environments and the distribution of metals. This study found that the spatial expansion of the two plants not only improved the supply capacity of the available sulfur in soils but also reduced the adverse effects of volatile sulfide on the growth of the two plants, which was of great significance in maintaining their strong competitiveness in PCM.