摘要
【目的】探究林分类型对土壤磷素有效性的影响及作用路径,揭示调控土壤磷素有效性的关键无机磷组分,为百山祖国家公园人工林土壤肥力维持和可持续经营提供理论依据。【方法】以百山祖国家公园杉木纯林、马尾松纯林、杉木马尾松混交林和杉木毛竹混交林为对象,测定0~10、10~20和20~40 cm土层土壤的基本性质、无机磷组分和有效磷含量等,分析全磷、有效磷和无机磷组分含量在林分类型间的差异,揭示土壤磷素有效性变化的关键驱动因素。【结果】4类林分0~40 cm土层土壤的全磷和有效磷含量分别为0.14~0.24 g·kg^(-1)和0.73~1.72 mg·kg^(-1),平均值分别为0.19 g·kg^(-1)和1.11 mg·kg^(-1),4类林分0~40 cm土层土壤的磷素活化系数为0.42%-0.72%,平均值为0.59%,且均以杉木毛竹混交林最高;4类林分0~40 cm土层土壤的各无机磷组分含量均表现出差异,杉木毛竹混交林均高于其他3类林分;除闭蓄态磷酸盐含量外,磷酸铝盐、磷酸铁盐、磷酸钙盐、可溶性磷含量等均与有效磷含量显著正相关(P<0.01);标准化主轴分析表明,磷酸铝盐含量与有效磷含量之间的异速增长指数显著低于1.00(P<0.01),磷酸铁盐含量、磷酸钙盐含量和可溶性磷含量与有效磷含量的异速增长指数均显著大于1.00(P<0.01);随机森林分析表明,磷酸铝盐、水解性氮和全氮含量是土壤有效磷含量的最主要调控因子;偏最小二乘法结构方程模型表明,林分类型通过影响土壤基本性质(全氮和水解性氮含量)、计量比(碳氮比和氮磷比)和无机磷组分(磷酸铝盐和磷酸铁盐含量)等对土壤有效磷含量起间接的正向调控作用。【结论】本研究区内,林分类型对土壤有效磷的直接效应不显著,但通过调控氮素水平、养分计量特征和无机磷组分等产生显著的间接效应。磷酸铝盐是土壤磷素有效性变化中最主要的调控因子。营建针阔混交林是提升百山祖国家公园人工林土壤磷素有效性的关键措施。
【Objective】The aim of this study is to investigate how different stand types affect soil phosphorus availability and to identify the critical inorganic phosphorus fractions that regulate this availability.This research seeks to provide a theoretical foundation for maintaining soil fertility and implementing sustainable management practices in the different plantation soils of Baishanzu National Park.【Method】This study took the four types of plantations as objectives,including Chinese fir pure forest,masson pine pure forest,Chinese fir-masson pine mixed forests,Chinese fir-moso bamboo mixed forests.We determined the basic properties,inorganic phosphorus fractions and available phosphorus content of the 0-10,10-20,and 20-40 cm soil layers,and analyzed the differences of total phosphorus content,available phosphorus content,and inorganic phosphorus fractions among stand types to reveal the key driving factors for the variations in soil phosphorus availability.【Result】The total phosphorus and available phosphorus content in the 0-40 cm soil layer across the four stand types were 0.14-0.24 g·kg^(-1)and0.73-1.72 mg·kg^(-1),respectively,with average values of 0.19 g·kg^(-1)and 1.11 mg·kg^(-1),respectively.The phosphorus activation coefficient in the 0-40 cm soil layer across the four stand types was 0.42%-0.72%,with an average value of 0.59%.Notably,these values reached their peak in the Chinese fir-moso bamboo mixed forests.The content of each inorganic phosphorus fraction in the0-40 cm soil layer across the four stand types showed differences,with the Chinese fir-moso bamboo mixed forests having higher values than the other three stand types.Except for occluded phosphate content,the contents of aluminum phosphate,iron phosphate,calcium phosphate,and soluble phosphorus were all significantly positively correlated with available phosphorus content(P<0.01).Standardized major axis analysis revealed that the allometric index for the relationship between aluminum phosphate content and available phosphorus content is significantly below 1.00(P<0.01).In contrast,the allometric index for iron phosphate content,calcium phosphate content,and soluble phosphorus content in relation to available phosphorus content are all significantly above 1.00(P<0.01).The random forest analysis identified aluminum phosphate content,hydrolyzable nitrogen content,and total nitrogen content as the most significant regulatory factors influencing available phosphorus content.The partial least squares structural equation model indicated that stand type indirectly enhanced available phosphorus levels by influencing basic soil properties such as total nitrogen content and hydrolyzable nitrogen content,stoichiometric ratios including organic carbon to total nitrogen and total nitrogen to total phosphorus,as well as inorganic phosphorus fractions such as aluminum phosphate content and iron phosphate content.【Conclusion】In this study area,while stand type does not have a significant direct impact on available phosphorus,it significantly influences available phosphorus indirectly by modulating nitrogen levels,nutrient ratios,and inorganic phosphorus fractions.Aluminum phosphate emerges as the most critical regulatory factor affecting soil phosphorus availability.Overall,developing mixed coniferous and broad-leaved forests will be a vital strategy for enhancing soil phosphorus availability in the plantation stands of Baishanzu National Park.
作者
周方
蒋科毅
叶兰华
沈庆华
童冉
朱念福
苗永朝
吴统贵
Zhou Fang;Jiang Keyi;Ye Lanhua;Shen Qinghua;Tong Ran;Zhu Nianfu;Miao Yongzhao;Wu Tonggui(Research Institute of Subtropical Forestry,Chinese Academy of Forestry, Hangzhou 311400;Nanjing Forestry University ,Nanjing 210037;Zhejiang Provincial Public Welfare Forest and State-Owned Forest Farm Management Station, Hangzhou 311400;Longquan Protection Center of Baishanzu National Park ,Longquan 323700)
出处
《林业科学》
EI
CAS
CSCD
北大核心
2024年第11期37-47,共11页
Scientia Silvae Sinicae
基金
百山祖国家公园科学研究项目(2021KFLY12)
中国林业科学研究院中央级公益性科研院所基本科研业务费专项资金资助项目(CAFYBB2022SY010)
国家重点研发计划项目(2023YFD2200900)。
关键词
林分类型
有效磷
无机磷组分
磷酸铝盐
百山祖国家公园
人工林
影响因素
stand types
available phosphorus
inorganic phosphorus fractions
aluminum phosphate
Baishanzu National Park
plantation
influencing factors