【摘要】 为了探究土壤水分和盐分对山东省胶州市东端芦苇(Phragmites australis)盐沼土壤水稳性团聚体的影响,通过室内模拟实验,选取粒径大于0.25 mm团聚体含量、团聚体平均质量直径、几何平均直径和分形维数4种指标,研究不同水、盐条件下土壤团聚体的水稳性特征。研究结果表明,在16种水、盐条件下,土壤中粒径小于0.25 mm团聚体含量最大,为33.90%～66.61%;随着培养时间的延长,粒径大于0.25 mm团聚体含量总体增加;随着土壤含水率增大,粒径大于0.25 mm团聚体含量、平均质量直径和几何平均直径都呈单峰型变化,当土壤含水率为30%时最大;随着土壤含盐量增大,粒径大于0.25 mm团聚体含量、平均质量直径和几何平均直径都在减小;分形维数与粒径大于0.25 mm团聚体含量的变化规律相反,两者显著负相关。土壤不同水、盐含量对芦苇盐沼土壤中的水稳性团聚体稳定性影响显著,相对于高水、高盐(土壤含水率为60%、土壤含盐量为2.4%)条件,土壤含水率为30%、土壤含盐量为0.9%更有利于土壤水稳性团聚体的形成和土壤结构的稳定。更多还原

【Abstract】 In order to investigate the effects of moisture and salinity on soil water-stable aggregates in Phragmites australis saltmarsh of east end of Jiaozhou, the characteristics of soil water-stable aggregates under different soil moistures and salinities were analyzed quantitatively by a laboratory experiment. The stability of soil water-stable aggregates was evaluated by four indicators including the content of water-stable aggregates greater than 0.25 mm, mean weight diameter, geometric mean diameter, and fractal dimension. The results showed that the content of aggregates less than 0.25 mm was the highest, which ranged from 33.90%to 66.61% under 16 kinds of moistures and salinities. The content of water-stable aggregates greater than 0.25 mm showed an increasing trend with the increase of culture time. With the increase of soil moisture, the content of water-stable aggregates greater than 0.25 mm, mean weight diameter and geometric mean diameter changed with single-peak type, which reached the maximum when soil moisture was 30%. With the increase of soil salinity, the content of water-stable aggregates greater than 0.25 mm, mean weight diameter, geometric mean diameter were decreased. Fractal dimension had a significant negative correlation with the content of water-stable aggregates greater than 0.25 mm. Moisture and salinity had significant effects on the stability of soil water-stable aggregates in coastal wetlands. Compared with high moisture(60%) and high salinity(2.4%), when soil moisture was 30% and soil salinity was 0.9%, they were more favorable to the formation of water-stable aggregates and the stability of soil structure.更多还原