【目的】探讨喀斯特不同石质生境中的青篱柴(Tirpitzia sinensis)叶片功能性状特征,为喀斯特地区植物生长适应性机理研究提供理论依据。【方法】以高倾角-短迹长-少转折-多连接-高密度-聚集型(Ⅰ)、中倾角-中迹长-多转折-中连接-中密度-均匀型(Ⅱ)、低倾角-长迹长-中转折-少连接-低密度-随机型(Ⅲ)3种石质生境中的典型优势灌木青篱柴为研究对象,采用单因素方差分析和相关性分析,研究其叶片功能性状对不同岩石裂隙网络结构和土壤理化性质的响应。【结果】不同石质生境的裂隙土壤养分和含水率在类型Ⅰ中最高、类型Ⅱ次之、类型Ⅲ最低,pH呈相反趋势,其中类型Ⅲ的土壤养分显著低于类型Ⅰ(P<0.05),土壤pH和含水率无显著差异。不同石质生境的叶片化学性状差异显著(P<0.05),而结构性状差异较小,叶片养分浓度和比叶面积在类型Ⅰ中最高、类型Ⅱ次之、类型Ⅲ最低,叶干物质含量呈相反趋势,叶片氮磷质量比和叶片厚度在类型Ⅱ中最高、类型Ⅲ次之、类型Ⅰ最低。岩石裂隙倾角和连接度是影响土壤理化性质的主要因子,土壤有机碳、全氮、速效氮、速效磷含量是影响叶片化学性状和叶面积的主要因子,而岩石裂隙网络结构中仅有连接度对其影响显著。总体上3种石质生境的叶片氮磷质量比大于16,表明青篱柴生长受磷限制,且生长速率低于同地带喀斯特其他灌木,均选择了较为保守的营养投资适应策略。【结论】岩石裂隙网络结构主要通过直接影响土壤理化性质进而间接影响叶片功能性状,其中叶片化学性状相比结构性状的可塑性更高;青篱柴在类型Ⅲ的石质生境中最易受到养分胁迫,进而在叶片功能性状上表现出了明显的耐贫瘠特征。

【Objective】This study aims to investigate the characteristics of leaf functional traits in Tirpitzia sinensis across different Karst fissure networks, and provide a theoretical basis for understanding plant growth adaptability mechanisms in Karst areas.【Method】In this study, we selected typical dominant shrub habitats of T. sinensis with various rock fissure characteristics: high dip angle, short track length, fewer turns, multiple connections, high density, and aggregation type (type Ⅰ); moderate dip angle, moderate track length, multiple turns, moderate connections, moderate density, and uniform type (type Ⅱ); and low dip angle, long track length, moderate turns, fewer connections, low density, and random type (type Ⅲ). We investigated the response of leaf functional traits to different rock fissure networks and soil physicochemical properties using One-way analysis of variance and correlation analysis. 【Result】The nutrient and water contents of fissure soil were the highest in type Ⅰ rocky habitats, followed by type Ⅱ, and the lowest in type Ⅲ, while soil pH showed an opposite trend. Soil nutrients in type Ⅲ were significantly lower than in type Ⅰ (P < 0.05), but there were no significant differences in soil pH or water content. Significant differences were found in leaf chemical traits among different rocky habitats (P < 0.05), but not in structural traits. Leaf nutrient concentration and specific leaf area were highest in type Ⅰ, followed by type Ⅱ and the lowest in type Ⅲ, with leaf dry matter content showing the opposite trend. Leaf N/P mass ratios and leaf thickness were the highest in type Ⅱ, followed by type Ⅲ, and the lowest in type Ⅰ. The dip angle and connectivity of rock fissures were the main factors affecting soil physicochemical properties. Soil organic carbon, total nitrogen, available nitrogen, and available phosphorus content were the primary factors influencing leaf chemical traits and leaf area, which were significantly affected by the connectivity of the rock fissure network. The leaf nitrogen/phosphorus mass ratio was higher than 16 across the three rocky habitats, which indicated that T. sinensis growth was phosphorus-limited. Compared with other Karst shrubs in the same area, the growth rates of T. sinensis in the three rocky habitats were slower, reflecting a more conservative nutritional investment strategy. 【Conclusion】The rock fissure network indirectly affects leaf functional traits primarily by altering soil physicochemical properties, with leaf chemical traits showing greater plasticity than structural traits. In type Ⅲ rocky habitats, T. sinensis is most susceptible to nutrient stress, demonstrating pronounced tolerance to nutrient-poor conditions in its leaf functional traits.