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林草资源研究 ›› 2025›› Issue (3): 83-91.doi: 10.13466/j.cnki.lczyyj.2025.03.010

• 科学研究 • 上一篇    下一篇

同域入侵植物意大利苍耳与刺苍耳的光合-水分生态位分化机制

庞立东1(), 武宝龙2, 陈利2, 王琪2, 庞萬隆3   

  1. 1.内蒙古财经大学 资源与环境经济学院,呼和浩特 010010
    2.乌兰察布市农牧业生态资源保护中心,内蒙古 乌兰察布 012000
    3.内蒙古农业大学 林学院,呼和浩特 010010
  • 收稿日期:2025-04-14 修回日期:2025-06-02 出版日期:2025-06-28 发布日期:2026-01-07
  • 作者简介:庞立东,副教授,主要从事生态保护与修复方面研究。Email:pang_stjcs@163.com
  • 基金资助:
    内蒙古自然基金项目“氮沉降对外来植物黄花刺茄入侵的影响机制”(2021MS03002);高校基本科研业务费领军项目“模拟氮沉降对外来植物黄花刺茄入侵性影响机制研究”(NCYWZ22008)

The mechanism of photosynthetic water niche differentiation between invasive species of Xanthium strumanum subsp.italicum and X.spinosum in the same domain

PANG Lidong1(), WU Baolong2, CHEN Li2, WANG Qi2, PANG Wanlong3   

  1. 1. College of Resource and Environmental Economics,Inner Mongolia University of Finance and Economics,Hohhot 010010,China
    2. Ulanqab City Agricultural and Animal Husbandry Ecological Resources Conservation Center,Ulanqab 012000,Inner Mongolia,China
    3. College of Forestry,Inner Mongolia Agricultural University,Hohhot 010010,China
  • Received:2025-04-14 Revised:2025-06-02 Online:2025-06-28 Published:2026-01-07

摘要: 为揭示同域入侵植物意大利苍耳与刺苍耳通过光合-水分策略分化实现共存的生态机制,以内蒙古海流水库为研究区,利用Li-6800光合仪测定叶片光合日动态参数(净光合速率Pn、蒸腾速率Tr、气孔导度Gs),结合土壤含水量空间自相关分析,拟合物种分布-水分响应曲线。结果表明:1)意大利苍耳光合曲线呈“双峰型”,午间光抑制程度低,最大净光合速率为47.91 μmol/(m2·s),比刺苍耳的最大净光合速率[17.2 μmol/(m2·s)]提高178.5%;刺苍耳则以晨间高光响应速率抢占碳同化先机。2)意大利苍耳主导高水分生境,土壤含水量大于20.4%,刺苍耳适应干旱区,土壤含水量小于12.7%,二者共存的阈值区间为14.8%~18.3%。3)意大利苍耳的水分利用效率随土壤含水量增加而增加(R2=0.83),符合水分集约利用策略;刺苍耳在土壤含水量为16.5%时水分利用效率峰值偏移,通过气孔振荡适应水分波动。二者通过“高光效-高蒸腾”策略组合实现光能-水分资源分割,其“光合-水分生态位互补”机制为入侵种协同扩散提供了生理生态学基础。

关键词: 意大利苍耳, 刺苍耳, 光合特性, 土壤水分, 生态位分化, 入侵机制

Abstract:

To elucidate the ecological mechanisms underlying the coexistence of two sympatric invasive species,Xanthium strumanum subsp.italicum and X.spinosum,through differentiation in photosynthetic-water utilization strategies,this study was conducted at Hailiu Reservoir in Inner Mongolia.The experimental design included establishing equidistant sampling plots from nearshore to offshore,encompassing monospecific stands(single-species dominant communities)and mixed communities.Leaf photosynthetic diurnal dynamics(net photosynthetic rate Pn,transpiration rate Tr,and stomatal conductance Gs)were measured using a Li-6800 photosynthesis system,and spatial autocorrelation analysis of soil water content was used to construct species distribution and water response curves.Key findings showed that:1)X. strumarium subsp. italicum exhibited a "bimodal" photosynthetic curve,with a maximum Pn of 47.91 μmol/(m2·s).This rate is 178.5% higher compared to that of X.spinosum[17.2 μmol/(m2·s)]and was associated with lower midday photoinhibition.In contrast,X.spinosum achieved a higher photosynthetic rate during morning hours,enabling it to seize an advantage in carbon assimilation early in the day.2)X.strumarium subsp. italicum dominated high-moisture habitats(>20.4%),while X.spinosum prevailed in arid zones(<12.7%),with coexistence occurring within a threshold interval of 14.8%-18.3%.3)X. strumarium subsp. italicum showed linearly increasing WUE with moisture(R2=0.83),indicative of water-conservative strategies,whereas X.spinosum displayed a WUE peak shift at a moisture level of 16.5%,regulated by stomatal oscillation.These results demonstrate that the two invaders achieve niche complementarity through "high photosynthetic efficiency/high transpiration" resource partitioning strategies,with their "photosynthetic-hydrological niche complementarity" mechanism providing a physiological basis for synergistic invasion.The findings offer critical insights for precision management of invasive plants in arid reservoir ecosystems.

Key words: Xanthium strumarium subsp. italicum, Xanthium spinosum, photosynthetic characteristics, soil moisture, niche differentiation, invasion mechanism

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