杉木纯林及其混交林土壤团聚体有机磷组分分布特征

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

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,从土壤团聚体的角度揭示有机磷组分对不同林分类型的响应特征。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<0.25 mm粒径团聚体的有机磷含量最高,而受粒径分布影响,<2 mm粒径团聚体的有机磷储量最高;<0.25 mm、>2 mm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>2 mm和<0.25 mm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。

With the method of field investigation and indoor analysis,we studied the distribution characteristics of organic phosphorus components in soil aggregates of different types of C.lanceolata stands including pure C.lanceolata stands,mixed C.lanceolata and Michelia macclurei forests,and mixed C.lanceolata and Mytilaria laosensis in Pingxiang,Guangxi,revealing the response characteristics of organic phosphorus components to different forest types from the perspective of soil aggregates.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 was the highest,and the storage of organic phosphorus in aggregate with particle size<2 mm was the highest due to the influence of particle size distribution.The stability indexes of 0.25 mm and>2 mm 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 >2 mm and <0.25 mm aggregates. Among the three forest types,the mixed forest of C. lanceolata and Michelia macclurei could effectively improve the stability of soil aggregatesand increase soil organic phosphorus reserves. Therefore, the selection of suitable mixed tree specieswould help to improve the quality of soil ecological environment and promote the sustainable managementof forest resources.