蒋长洪 漆基海 翁涛 穆君 白小节 高露 胡小润 臧丽鹏 何跃军

摘 要：黔北丹霞地貌是桫椤（Alsophila spinulosa）种群集中分布区，不同物种组成的桫椤群落在土壤养分是如何随土层深度垂直分布的特征缺乏关注。探索桫椤群落土壤养分及有机质含量随土层深度的变化特征，对深入探索桫椤种群濒危机制及保育技术具有重要意义。论文选择贵州赤水和习水国家自然保护区丹霞地貌4个典型桫椤群落样地进行样方调查，并采集0～10 cm、10～20 cm、20～30 cm土壤样品，测定土壤全氮、全磷、全钾、碱解氮、速效磷、速效钾及有机质含量，分析不同群落样地和不同土层深度对土壤性质的影响。结果表明：不同桫椤群落类型和土层深度共同影响土壤全氮和有效态氮、磷、钾含量和有机质含量，且二者交互作用对有效态养分和有机质显著影响;土壤全氮、碱解氮、速效钾和有机质含量，N/P、N/K、P/K比率随土层深度增加而降低，而速效磷则是随土层深度增加而增加趋势。研究表明，黔北丹霞地貌桫椤群落土壤养分和有机质含量随群落物种组成和土层深度变化而垂直分异。

关键词：桫椤;土壤养分;有机质;垂直分异

中图分类号：Q948

文献标识码：A

文章编号：1008-0457（2021）04-0012-06

国际DOI编码：10.15958/j.cnki.sdnyswxb.2021.04.002

Abstract：The Danxia landform in northern Guizhou is one pivot area of natural Alsophila spinulosa.However，the vertical distribution of soil nutrients in different species of A.spinulosa community with soil depth was not lack of attention.Therefore，studying on variations in soil nutrient and organic matter contents among soil depths acted a key role in exploring the endangered mechanisms and conservation technology of A.spinulosa.This study investigated four A.spinulosa communitiesin Chishui and Xishui national natural reserve of Guizhou province，China.By performing community investigation，we collected soil samples from depth of 0～10 cm，10～20 cm，20～30 cm and analyzed soil total nitrogen content，total phosphorus content，total potassium content，available nitrogen content，available phosphorus content，available potassium content and organic matter content to understand the response of soil properties to community and soil depth.Results showed that both different types of A.spinulosa communities and soil depth had significant influence on soil total nitrogen content，soil available nitrogen，available potassium content and organic matter content.And this interactive effect also significantly influenced soil available nutrient and organic matter contents.Soil total nitrogen，available nitrogen，available potassium，organic matter content，the ratio of N/P，N/K，P/K decreased with soil depth increasing.However，the soil available phosphorus content had an increasing trend as soil depth increased.In total，the soil nutrient and organic matter contents of A.spinulosa communities in Danxia landform in northern Guizhou had significant vertical variations with species composition and soil depth.

Keywords：Alsophila spinulosa ;soil nutrient;organic matter;vertical variations

桫欏（Alsophila spinulosa）是白垩纪末、第三纪早期冰川时期的孑遗植物。受人类活动干扰和气候变迁等因素影响，桫椤种群数量急剧减少并处于濒危状态，桫椤已成为我国重要的珍稀保护物种之一。研究桫椤群落及其生境特征对探索古环境演变及物种的形成与分布具有重要的理论和保护价值[1]。……