不同林龄刺槐解剖结构及生理特性  

Anatomical structure and physiological characteristics of Robinia pseudoacacia of different stand ages

作　　者：刘青[1] 王云霞[1] 曾岩 冒吉荣 徐肖阳 刘莹[1] LIU Qing;WANG Yunxia;ZENG Yan;MAO Jirong;XU Xiaoyang;LIU Ying(College of Soil and Water Cons ion Science and Engineering,Northwest A&F University,Yangling 712100,Shaanxi,China)

机构地区：[1]西北农林科技大学水土保持科学与工程学院,陕西杨凌麦712100

出　　处：《应用生态学报》2023年第12期3256-3262,共7页Chinese Journal of Applied Ecology

基　　金：国家自然科学基金重点项目(42130717)资助。

摘　　要：全球变暖导致干旱强度增大、频率增加,探究黄土高原不同林龄刺槐林对干旱的响应机制对于理解该区人工林生产力稳定性具有重要意义。本研究以黄土高原半干旱区刺槐幼龄林、中龄林和成熟林为对象,探究不同林龄木质部解剖特征、水力特征和非结构性碳水化合物含量及其之间的相关关系。结果表明:幼龄林、中龄林的导管直径、纹孔总面积、纹孔面积、附着物面积和附着比例均显著大于成熟林,而纹孔密度显著小于成熟林。导管直径、纹孔面积和附着物面积与导水率之间存在显著相关性。幼龄、中龄和成熟林枝条导水率分别为2.30、2.12和0.76 kg·m^(-1)·s^(-1)·MPa^(-1),栓塞程度分别为54.5%、53.8%和45.1%。导水率与可溶性糖和淀粉含量之间存在显著相关性。幼龄、中龄和成熟林枝条木质部可溶性糖含量分别为4.9%、4.2%和3.8%。成熟林刺槐木质部生长力下降,形成具有较多较小纹孔的小导管,在维持水力安全的同时降低了水分运输效率,组织内维持生长代谢的非结构性碳水化合物含量显著降低。本研究解释了不同林龄刺槐人工林对干旱的响应机制,为黄土高原不同林龄刺槐人工林的管理与抚育提供了科学依据。Drought intensity and frequency have been increased as a result of global warming. Exploring the drought resistance mechanism of Robinia pseudoacacia plantations of different stand ages on the Loess Plateau is crucial for understanding the stability of forest productivity in the region. We investigated anatomical traits, hydraulic function, and non-structural carbohydrate content of the xylem, as well as their association, in R. pseudoacacia plantations of different stand ages in a semi-arid region. The results showed that the vessel diameter, total pit membrane area, pit membrane area, vesture area, and vestured overlap of young and middle-aged stands were larger than those of mature stands, and the pit density was significantly lower in mature stands. Hydraulic conductivity was significantly related to vessel diameter, pit membrane area, and vesture area. Hydraulic conductivities of branches in young, middle-aged, and mature stands were 2.30, 2.12, and 0.76 kg·m^(-1)·s^(-1)·MPa^(-1), respectively, with embolism values of 54.5%, 53.8%, and 45.1%. Hydraulic conductivity was significantly related to soluble sugar and starch contents. The soluble sugar contents of branches in young, middle-aged and mature stands were 4.9%, 4.2%, and 3.8%, respectively. Xylem growth capacity of R. pseudoacacia in mature stand declined, resulting in the formation of small vessels with many small pits, which reduced hydraulic conductivity while maintaining hydraulic safety, resulting in a decrease of non-structural carbohydrates content. This study revealed the drought response mechanism of R. pseudoacacia plantations with different ages, providing a scientific foundation for the management and nurturing of R. pseudoacacia plantations on the Loess Plateau.

关 键 词：干旱 解剖结构 导水率 栓塞 非结构性碳水化合物 

分 类 号：S792.27[农业科学—林木遗传育种]