Effects of Bioturbation by Macrobenthos Living on the Tidal Flat on the Bottom-Mud Environment and Concentration Profiles of Nutrient Salts

在野外实测和分析资料的基础上，研究了潮滩大型底栖生物扰动对滩底环境和营养盐浓度分布的影响。本文的研究结果总结如下：1。掌握了各研究点大型底栖动物的种类及其数量分布。此外，还发现潮滩表面大型底栖动物及其筑巢孔的数量分布受空气和泥浆温度的强烈影响。底泥氧化还原电位（Eh）与大型底栖动物及其筑巢孔数量分布有密切关系。因此，认为对底泥环境影响最大的生物扰动是大型底栖动物的巢孔形成。根据涨潮、退潮和大型底栖动物扰动强度的变化，估计底泥氧化还原层的垂直分布有明显的周期性变化。4 .大型底栖动物的数量分布及其筑巢孔与底泥中Eh的垂直剖面及底泥孔隙水中NH_4^+和NO_3^-浓度有密切的关系。估计底泥中有机质的分解和矿化，即细菌生产营养盐的过程，是在退潮涨潮等环境变化和大型底栖动物在底泥中形成巢孔的条件下有效发生的。从理论和实验上明确了波流复合作用下底泥重悬浮的机理，这是影响底泥中营养盐浓度分布的物理作用之一

The effects of bioturbation by macrobenthos living on the tidal flat on the environment in the bottom-mad and the concentration profiles of nutrient salts were investigated on the basis of field measured and analytical data. The results obtained by this research are summarized as follows :1. The species of macrobenthos and its number distribution in the study sites were grasped. Moreover, it was found that the number distributions of macrobenthos and its nesting holes on the tidal flat surface were strongly affected by air and mud temperature.2. The close relationships were observed between the redox potential (Eh) in the bottom-mud, and the number distributions of macrobenthos and its nesting hole. Therefore, it was assumed that the most important bioturbation that influenced on the environment in the bottom-mud was the nesting hole formation by macrobenthos.3. It was estimated that the vertical distributions of oxidized and reduced layers in the bottom-mud changed remarkably and periodically according to ebb and flood, and variation of bioturbation strength by macrobenthos.4. The close relationship was observed between the number distributions of macrobenthos and its nesting hole, and the vertical profiles of Eh in the bottom-mud and NH_4^+ and NO_3^- concentrations in the bottom-mud pore water.5. It was estimated that the decomposition and mineralization of organic matters, that is, the nutrient salts production processes by bacteria in the bottom-mud took place effectively under the environment variations that occurred according to ebb and flood, and nesting hole formation by macrobenthos in the bottom-mud.6. The resuspension mechanism of bottom-mud under the combined wave-current flows, which was one of physical action that affected on the concentration profiles of nutrient salts in the bottom-mud, was made clear theoretically and experimentally