不同南药-橡胶复合系统下橡胶树叶片稳定碳同位素及水分利用效率的变化

Variation of Foliar Stable Carbon Isotopes and Water use Efficiency of Different Herb-rubber Intercropping systems

选取南药-橡胶复合种植系统(益智-橡胶、五指毛桃-橡胶、葛根-橡胶),以及橡胶单作系统为研究对象,利用稳定碳同位素法研究不同南药-橡胶复合系统下橡胶树叶片δ^(13)C值及水分利用效率WUE的季节变化,分析其水分利用效率的变化特征,以期遴选出水分关系配置合理的复合橡胶林栽培模式。结果表明:益智-橡胶与五指毛桃-橡胶等复合系统的橡胶树叶片δ^(13)C值及WUE显著高于橡胶单作与葛根-橡胶复合系统;干季橡胶树受到干旱胁迫,各胶园δ^(13)C值和WUE显著高于雨季,且以橡胶单作δ^(13)值和WUE最低;各胶园土壤含水量整体差异小,季节变化一致,仅在0~20 cm土层益智-橡胶与五指毛桃-橡胶等复合系统的土壤含水量显著大于橡胶单作系统与葛根-橡胶复合系统,其它土层差异不显著;各南药-橡胶复合系统的正午水势Ψ_(md)均大于橡胶单作系统;葛根-橡胶复合系统的作用不明显,所有特征都与橡胶单作系统相似。该研究揭示了南药-橡胶复合系统内的橡胶树水分利用效率,表明益智-橡胶与五指毛桃-橡胶等南药-橡胶复合种植模式是值得推广的胶农复合生态系统。

This study selected herb-rubber intercropping systems and rubber monoculture system as the research object,the stable carbon isotope method was used to study the seasonal change of rubber blades δ^(13)C value and water use efficiency(WUE)under different herb-rubber intercropping system,understand the change characteristics of WUE in order to find water relations configuration reasonable of rubber Intercropping systems.The results showed that the δ^(13)C value of rubber leaves and WUE in Yizhi(Alpinia oxyphylla Miq)-rubber and Wuzhimaotao(Ficus hirta Vahl)-rubber Intercropping systems were significantly higher than those in the monoculture rubber and gegen(Pueraria lobata)-rubber Intercropping systems.Under drought stress,the δ^(13)C value and WUE of rubber plantations in dry season were significantly higher than those in rainy season,and theδ13 value and WUE of rubber monoculture were the lowest.The overall difference of soil water content in each rubber plantations was small,and the seasonal variation was consistent.Only in 0~20cm soil layer,the soil water content of the Yizhi-rubber and Wuzhimaotao-rubber Intercropping system was significantly higher than that of the rubber monoculture system and the gegen-rubber intercropping system,and the difference in other soil layers was not significant.The herb-rubber intercropping systems of water potential at noon(Ψmd)were greater than the rubber monoculture system.The effect of gegen-rubber intercropping system was not obvious,and all the characteristics were similar to that of rubber monoculture system.This study revealed the WUE of rubber trees in the herd-rubber intercropping system,which indicated that the Chinese herbal medicine and rubber composite planting modes,such as Yizhi rubber and five fingers-peach-rubber,were worth popularizing in the composite ecosystem of rubber farmers.