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草业学报 ›› 2026, Vol. 35 ›› Issue (1): 65-78.DOI: 10.11686/cyxb2025073

• 研究论文 • 上一篇    下一篇

降水变化对荒漠草原植物群落主要物种气孔形态和光合生理特性的影响

邓文辉1(), 宋珂辰1, 张浩1, 管思雨1, 雍嘉仪1, 谢铁娜2, 胡海英1()   

  1. 1.宁夏大学林业与草业学院,宁夏 银川 750021
    2.宁夏大学科学技术研究院,宁夏 银川 750021
  • 收稿日期:2025-03-06 修回日期:2025-04-21 出版日期:2026-01-20 发布日期:2025-11-13
  • 通讯作者: 胡海英
  • 作者简介:E-mail: haiying@nxu.edu.cn
    邓文辉(1999-),男,甘肃天水人,在读硕士。E-mail: 1657187804@qq.com
  • 基金资助:
    国家自然科学基金项目(32160406);宁夏高等学校一流学科建设(草学学科)项目(NXYLXK2017A01)

Effects of changes in precipitation on stomatal morphology and photosynthetic and physiological characteristics of major species in desert steppe plant communities

Wen-hui DENG1(), Ke-chen SONG1, Hao ZHANG1, Si-yu GUAN1, Jia-yi YONG1, Tie-na XIE2, Hai-ying HU1()   

  1. 1.College of Forestry and Grassland,Ningxia University,Yinchuan 750021,China
    2.Institute of Science and Technology,Ningxia University,Yinchuan 750021,China
  • Received:2025-03-06 Revised:2025-04-21 Online:2026-01-20 Published:2025-11-13
  • Contact: Hai-ying HU

摘要:

本研究以宁夏荒漠草原植物群落的主要物种短花针茅、赖草、牛枝子、银灰旋花、远志为对象,设置增加50%自然降水量(PA),自然降水量(CK),减少50%自然降水量(PR)3个处理,研究了不同降水量下,荒漠草原主要植物叶片光合、气孔形态特征、水分利用效率的变化,揭示了荒漠草原主要植物对降水改变的光合适应机制,以期为荒漠草原生态系统管理以及应对全球气候变化趋势所带来的影响提供理论依据。结果表明:在荒漠草原,植物通过增加叶片气孔的周长和面积来降低蒸腾速率和气孔导度,从而降低净光合速率、提高水分利用效率达到适应干旱环境的目的。其中银灰旋花的净光合速率对降水量变化最敏感,PA处理下的净光合速率是PR处理的6.65倍,同时其水分利用效率最低。而赖草对水分的利用能力最高,短花针茅和远志次之。各主要群落植物的比叶面积指数均随降水量减少而显著增大(P<0.05)。植物叶片气孔形状偏向于圆形会增加植物的水分利用效率,而叶片气孔形状偏向于长形会增加植物的净光合速率。综合分析后可以看出,这5种植物中光合和水分利用的生态适应能力的高低为短花针茅>赖草>远志>银灰旋花>牛枝子。

关键词: 荒漠草原, 降水变化, 光合作用, 气孔特征, δ13C, 比叶面积

Abstract:

In this study, we investigated the photosynthetic adaptation mechanisms of five dominant plant species in the desert steppe of Ningxia (Stipa brevifloraLespedeza secalinusLespedeza potaniniiConvolvulus ammannii, and Polygala tenuifolia) under altered precipitation regimes. Three treatments were applied: precipitation increased by 50% (PA), natural precipitation (CK), and precipitation decreased by 50% (PR). We examined changes in leaf photosynthetic parameters, stomatal morphology, and water use efficiency (WUE) to elucidate how these plants adapt to varying water availability. The results show that desert steppe plants were able to enhance their drought tolerance by increasing the stomatal perimeter and area, thereby reducing the transpiration rate and stomatal conductance. These adaptations lowered the net photosynthetic rate (Pn) and increased the WUE. C. ammannii exhibited the highest sensitivity of Pn to changes in precipitation, with the Pn in the PA treatment being 6.65-fold that in the PR treatment, although it had the lowest WUE among the five plants. L. secalinus had the highest WUE, followed by S. breviflora and P. tenuifolia. The specific leaf area (SLA) of all species significantly increased with reduced precipitation (P<0.05). Stomatal shape also influenced drought adaptation; rounder stomata were correlated with higher WUE, whereas elongated stomata were correlated with enhanced Pn. As indicated by changes in photosynthesis and water use, the five plants were ranked from highest ecological adaptability to lowest as follows: S. breviflora>L. secalinus>P. tenuifolia>C. ammannii>L. potaninii. These findings provide theoretical insights into the management of desert steppe ecosystems under the conditions of global climate change.

Key words: desert steppe, precipitation variability, photosynthesis, stomatal characteristics, δ13C, specific leaf area