Can intercropping with the world’s three major beverage plants help improve the water use of rubber trees?
Can intercropping with the world’s three major beverage plants help improve the water use of rubber trees?
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与世界三大饮料植物间作有助于提高橡胶树的用水量吗？
DOI：
10.1111/1365-2664.12730
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发表时间：
2016
影响因子：
5.7
通讯作者：
chen chunfeng
中科院分区：
文献类型：
--
作者：
wu junen;liu wenjie;chen chunfeng
中国大陆、东南亚和中国西南部橡胶种植园的急剧扩张造成了许多生态环境问题，特别是负面的水文后果。这些问题逐渐恶化，并对橡胶农业构成可怕的威胁，特别是在极端天气事件日益频繁的情况下。虽然橡胶农林复合系统被认为是提高橡胶农业可持续性和环境保护的最佳解决方案，但在这类系统中很少有人研究植物水分利用及其相关的相互作用。我们主要使用稳定同位素(δD，δ18O和δ13C)方法来测试间作是否能提高西双版纳3种有前途的农林复合系统(即橡胶与茶叶、咖啡和可可)的水分利用和极端天气(在本研究中为极端寒冷和干旱)的耐受性。这一特点反映在其应对严重季节性干旱的能力上，使其能够避免物种间对水的竞争。橡胶树表现出浪费水分的行为，除非它们与茶叶或咖啡间作。然而，这些间作树种表现出耐旱性策略，并保持较低的水分利用效率，以增强它们对表层土壤水分的竞争能力。间作叶片稳定的δ~(13)C值表明，所有农林复合系统都具有稳定的内部小气候环境或较高的抗逆性。这项研究表明，种间对水分的竞争可以提高避旱植物(即橡胶树)的水分利用效率，并导致橡胶农林复合系统(即橡胶与茶叶、咖啡和可可)植物根系分布的互补性。所有农林间作系统都具有较高的抗旱性，但茶树是最适合间作的作物，因为种间对水分的竞争适中，而且农林复合系统保留了更多的土壤水分，提高了橡胶树的水分利用效率。考虑到茶树的根系特点，我们建议选择与橡胶树间作的作物应具有相对固定的水分利用模式，侧根短，细根量适中，与橡胶树的根系在浅层重叠。
The dramatic expansion of rubber plantations in mainland South‐East Asia and south‐west China has caused many eco‐environmental problems, especially negative hydrological consequences. These problems have gradually worsened and pose formidable threats to rubber agriculture, especially in the light of increasingly frequent extreme weather events. Although rubber‐based agroforestry systems are regarded as the best solution for improving the sustainability of rubber agriculture and environmental conservation, plant water use and related interactions have rarely been examined in such systems.We primarily used stable isotope (δD, δ18O and δ13C) methods to test whether intercropping could improve the water use and extreme weather tolerance (extreme cold and drought in our study) of rubber trees in three types of promising agroforestry systems (i.e. rubber with tea, coffee and cocoa) in Xishuangbanna, China.We found that the rubber tree is a drought‐avoidance plant with strong plasticity with respect to water uptake. This characteristic is reflected by its ability to cope with serious seasonal drought, allowing it to avoid interspecific competition for water. The rubber trees showed wasteful water behaviour unless they were intercropped with tea or coffee. However, these intercropped species exhibited drought‐tolerance strategies and maintained lower water use efficiencies to strengthen their competitive capacity for surface soil water. The stable δ13C values of the intercrop leaves indicated that all the agroforestry systems have stable internal microclimatic environments or higher resistance.Synthesis and applications. This study suggests that interspecific competition for water can enhance the water use efficiency of drought‐avoidance plants (i.e. rubber trees) and lead to complementarity between the root distributions of plants in rubber agroforestry systems (i.e. rubber with tea, coffee and cocoa). All agroforestry systems have higher resistance, but tea was the most suitable intercrop in terms of water use because the interspecific competition for water was moderate and the agroforestry system retained much more soil water and improved the water use efficiency of the rubber tree. Considering the root characteristics of the tea trees, we suggest that the crops selected for intercropping with rubber trees should have a relatively fixed water use pattern, short lateral roots and a moderate amount of fine roots that overlap with the roots of the rubber trees in the shallow soil layer.