【目的】揭示不同竞争关系对高节竹(Phyllostachys prominens)叶片功能性状及光合产物的调控机制,探讨叶片形态特征、色素含量和非结构性碳水化合物的变化规律及相互关系,对竹林地力维护和可持续经营提供科学依据。【方法】选取高节竹-毛竹(P. edulis)混交林(PM)、高节竹-针阔叶树混交林(PB)和高节竹纯林(PP)3种林分类型,分析不同竞争关系下高节竹叶片的形态特征、色素含量和非结构性碳水化合物(NSCs)积累特征,利用主成分分析和偏最小二乘结构方程模型探讨种间与种内竞争对其生长策略及适应机制的影响差异。【结果】PM林分显著促进高节竹叶片增大与生物量积累,其叶长、叶宽、叶面积、叶干质量和比叶面积均显著高于PP和PB林分(P<0.05),但叶厚和叶干物质含量则显著降低。PM林分叶片叶绿素a、叶绿素b和总叶绿素含量显著高于PP和PB林分(P<0.05),而PP林分显著提高了叶绿素a/b。高节竹叶片NSCs成分含量分析表明,PM和PP林分中的高节竹叶片可溶性糖含量和可溶性糖与淀粉质量比均显著高于PB林分(P<0.05)。主成分分析和结构方程模型(PLS-SEM)揭示,不同竞争关系通过影响高节竹生长特性,进一步调节叶片形态,并显著影响色素合成和NSCs积累(P<0.001)。其中,立竹高度与叶片形态特征呈强正相关,而叶片形态对色素和NSCs表现出显著的正向调控。【结论】在不同林分中,高节竹通过调整叶片形态和生理特性来适应竞争环境。在与毛竹竞争时,高节竹通过调整资源获取策略增强生长能力,促进叶片伸展和糖积累,而在针阔叶树混交林和纯林中,则通过优化叶片碳分配,提高其耐受性和资源利用效率。

【Objective】This study clarifies how different competition relationships affect leaf functional traits in Phyllostachys prominens, and examines the variation and interdependence of leaf morphology, pigment content, and non-structural carbohydrates (NSCs), providing a scientific basis for mixed-forest management and bamboo stand cultivation.【Method】We examined three stand types: P. prominens-P. edulis mixed forest (PM), P. prominens-broadleaf-conifer mixed forest (PB), and pure P. prominens forest (PP). Leaf morphological traits, pigment content, and NSCs accumulation characteristics were analyzed under different competitive conditions. Principal component analysis and partial least squares structural equation modeling (PLS-SEM) were employed to explore the differential impacts of interspecific and intraspecific competition on growth strategies and adaptive mechanisms.【Result】The PM stand significantly promoted leaf expansion and biomass accumulation in P. prominens, resulting in greater leaf length, width, area, dry mass, and specific leaf area compared to the PP and PB stands (P< 0.05), whereas leaf thickness and dry matter content were significantly lower. Chlorophyll a, chlorophyll b, and total chlorophyll contents were significantly higher in the PM stand than those in the PP and PB stands (P< 0.05), while the PP stand exhibited a significantly higher chlorophyll a/b. Soluble sugar content and soluble sugar-to-starch mass ratio were significantly higher in the PM and PP stands than those in the PB stand (P< 0.05). Principal component analysis and partial least squares structural equation modeling indicated that different competition relationships influenced bamboo growth characteristics, which in turn regulated leaf morphology and significantly affected pigment synthesis and NSCs accumulation (P< 0.001). Notably, bamboo height was strongly positively correlated with leaf morphological traits, which in turn, exhibited significant positive effects on pigment contents and NSCs.【Conclusion】P. prominens adapts to competitive environments by modifying its leaf morphology and physiological traits. It employs a resource acquisition strategy to enhance growth, promoting leaf expansion and sugar accumulation when competing with P. edulis, while optimizing carbon allocation to improve stress tolerance and resource use efficiency in broadleaf-conifer forests and pure stands.