落叶松土壤有机磷形态与林木生长量的关系

采用Bowman-Cole有机磷分级体系，对落叶松人工林不同发育阶段根际与非根际土壤活性有机磷、中等活性有机磷、中稳性有机磷和高稳性有机磷含量的变化及其与有效磷和林木生长量的关系进行了研究。结果表明，构成落叶松人工林土壤有机磷的主要成分是中等活性有机磷和中稳性有机磷，两者之和占有机磷总量的77.07％～86．68％，根际土壤活性有机磷和中等活性有机磷是不同发育阶段土壤有效磷的主要来源，根际土壤有机磷总量、活性有机磷含量、中稳性有机磷含量和高稳性有机磷含量从幼龄林到近熟林随林龄递增而降低，近熟林之后有所增加，根际土壤中等活性有机磷含量随林龄变化不明显，非根际土壤各形态有机磷含量随林龄递增而呈波动性增加趋势，各发育阶段林木胸径、树高定期平均生长量与活性有机磷含量和有效磷含量关系最为密切。

Relationship between soil organic phosphorus forms in larch plantations and tree growth

Using the organic phosphorus fractionation system suggested by Bowman and Cole, this paper studied the dynamics of labile, moderately labile, moderately resistant, and highly resistant organic phosphorus in rhizosphere and non-rhizosphere soil at different development stages of larch, and their relationships with soil available phosphorus and tree growth yield. The results showed that the main components of soil organic phosphorus in larch plantation were moderately labile and moderately resistant organic phosphorus, amounted to 77.07%-86.68% of the total organic phosphorus. The labile and moderately labile organic phosphorus in rhizosphere soil were the main sources of soil available phosphorus at different development stages of larch. The contents of total organic phosphorus, labile organic phosphorus, moderately resistant organic phosphorus and highly resistant organic phosphorus in rhizosphere soil decreased with stand ages from young stand to near mature stand, but increased from near mature stand to mature stand. No apparent change of the moderately labile organic phosphorus content was found over stand ages in rhizosphere soil. The contents of various organic phosphorus forms presented a fluctuating increasing tendency in non-rhizosphere soil as stand ages increased. There was a close relationship between the increments of periodic average diameter at breast height and periodic average height and the contents of soil labile organic phosphorus and available phosphorus.