杉木纯林及其混交林土壤团聚体有机磷组分分布特征研究

磷素是植物生长不可缺少的营养元素,而有机磷是土壤磷库的重要组成部分,其活性大小与土壤供磷能力密切相关。采用野外调查与室内分析相结合的方法,以广西凭祥杉木纯林、杉木-火力楠混交林、杉木-米老排混交林为研究对象,探讨了不同杉木林分类型土壤团聚体中有机磷组分的分布特征,结果表明：除高稳性有机磷主要分布在大粒径团聚体中外,其余组分有机磷含量均表现为随着粒径减小而增加,其中<0.25mm粒径团聚体的有机磷含量最高,而受粒径分布影响,<2mm粒径团聚体的有机磷储量最高；<0.25mm、>2mm粒径团聚体和土壤团聚体稳定指标与各有机磷组分储量呈极显著正相关,在保持土壤稳定的基础上,可通过提高>2mm和<0.25mm粒径团聚体的占比能有效增加土壤有机磷储量；在3种林分类型中,杉木-火力楠混交林能够有效的提高土壤团聚体稳定性,提高土壤有机磷含储量。因此,选择合适的混交树种,有助于土壤生态环境质量提升及促进森林资源的可持续经营管理。

Distribution Characteristics of Soil Aggregate Organic Phosphorus in Pure and Mixed Cunninghumia lanceolata

Phosphorus is an indispensable nutrient element for plant growth, while organic phosphorus is an important component of soil phosphorus pool, and its activity is closely related to soil phosphorus supply capacity. With the method of field investigation and indoor analysis, the distribution characteristics of organic phosphorus components in soil aggregates of different types of C. lanceolata stands were studied by taking pure C. lanceolata stands, mixed C. lanceolata and Michelia macclurei forests, and mixed C. lanceolata and Mytilaria laosensis in Pingxiang, Guangxi. The results showed that except highly stable organic phosphorus, which was mainly distributed in large particle size aggregates, the content of organic phosphorus in other components increased with the decrease of particle size, The content of organic phosphorus in aggregate with particle size<0.25 mm is the highest, and the storage of organic phosphorus in aggregate with particle size<2 mm is the highest due to the influence of particle size distribution< The stability indexes of 0.25mm and>2mm aggregates and soil aggregates were significantly positively correlated with the reserves of various organic phosphorus components. On the basis of maintaining soil stability, the reserves of soil organic phosphorus could be effectively increased by increasing the proportion of>2mm and<0.25mm aggregates; Among the three forest types, the mixed forest of C. lanceolata and Michelia macclurei can effectively improve the stability of soil aggregates and increase soil organic phosphorus reserves. Therefore, the selection of suitable mixed tree species will help to improve the quality of soil ecological environment and promote the sustainable management of forest resources.