摘要
作为一种模仿热带雨林结构而构建的复合式橡胶种植林,丛林式橡胶林比纯橡胶林更符合可持续发展的理念。通过研究丛林式橡胶林内植物的水分利用策略以探索植物合理的种间配置结构,对于优化现存胶园具有重要的指导意义。本研究选取位于中国科学院西双版纳热带植物园内的丛林式橡胶林为实验对象,以纯橡胶林为对照,通过氢氧稳定同位素方法定量区分植物的水分来源,同时通过植物叶片碳同位素比较植物水分利用效率,进而探究植物的水分利用策略。结果表明:(1)丛林式橡胶林平均土壤含水量显著高于纯橡胶林,说明丛林式橡胶林内水分条件更好。(2)纯橡胶林中橡胶树在雨季的水分来源主要为0～5 cm土壤水(81.6%),干季主要利用5～15 cm土壤水(49.6%),对不同深度土壤水利用比例季节性波动大。丛林式橡胶林中橡胶树对不同深度土壤水利用比例季节性波动小,林内浦竹仔和其余乔木种在雨季对浅层土壤水利用比例比干季高,橡胶树为避免种间竞争而增加深层土壤水的利用比例,有利于根系向更深处发展。(3)相较于纯橡胶林,丛林式橡胶林内橡胶树叶片δ^(13)C值季节差异小,说明其水分利用效率稳定。在干季,丛林式橡胶林内橡胶树叶片δ^(13)C值低于纯橡胶林内橡胶树,说明橡胶树在丛林式橡胶林内受到干旱胁迫更弱,此时橡胶树δ^(13)C值高于雨季,橡胶树以此应对季节性干旱胁迫。总的来说,丛林式橡胶林内土壤水分条件更好,植物水分利用策略更为灵活,是一种值得推广的可持续橡胶林管理措施。
Jungle rubber,a rubber agroforestry based on tropical rainforest structure,is more in line with the thought of sustainable development for rubber garden than rubber monoculture.Thus,exploring the interspecific composition and structure of jungle rubber by investigating plant water use strategies will help optimize the efficiency of current rubber monoculture. The aim of this study was to compare the water use strategies of plants between jungle rubber and rubber monoculture. The stable isotope( δD,δ18O,and δ13C) methods were used to investigate the plants’ water source and use efficiency. The results showed that:( 1) Soil water content in jungle rubber was higher than that in rubber monoculture in both rainy and dry seasons,indicating that soil water condition of jungle rubber was better.( 2) The absorbed water of rubber trees in rubber monoculture from the diverse soil layers varied considerably between the two seasons. During the rainy season,greater water uptake of the monoculture rubber trees was from the 0-5 cm soil layer,occupying 81.6% of total water source,while during the dry season,the higher uptake was from the 5-15 cm soil layer,with a proportion of 49.6%. However,the water source of rubber trees in jungle rubber was relatively steady,and their water uptake from the deeper soil layer was greater than from the shallow soil layer,conducing to a deeper expansion of roots.( 3) The water use efficiency of rubber trees in jungle rubber was generally more stable than that in rubber monoculture. Thus,the difference of leaf δ13C values of rubber trees in jungle rubber was smaller than that in rubber monoculture during the dry season,showing that the rubber trees in jungle rubber had a weaker drought stress. Meanwhile,rubber trees adjusted their water use strategies by enhancing leaf δ13C to improve their tolerance of seasonal drought. In conclusion,jungle rubber was a promising sustainable management with better soil water condition and more flexible plant water use strategies compared to the traditional rubber monoculture.
作者
曾欢欢
刘文杰
吴骏恩
朱习爱
ZENG Huan-Huan;LIU Wen-Jie;WU Jun-En;ZHU Xi-Ai(Key Laboratory of Tropical Forest Ecology,Xishuangbanna Tropical Botanical Garden,Chinese Academy of Sciences,Mengla 666303,Yunnan,China;University of Chinese Academy of Sciences,Beijing 100049,China)
出处
《生态学杂志》
CAS
CSCD
北大核心
2019年第2期394-403,共10页
Chinese Journal of Ecology
基金
博士后创新人才计划(BX201700278)
国家自然科学基金项目(31570622)资助
