| 摘要: |
| 【目的】研究核桃(Juglans regia)-小麦(Triticum aestivum)复合系统中细根的分布格局及形态变异，为种间关系研究及农林复合系统的合理设计提供依据。【方法】以核桃、小麦单作为对照，采用根钻法取样，用WinRHIZO根系分析系统对根系形态进行分析，比较核桃 小麦复合系统与单作系统中植物细根的空间分布和形态差异。【结果】①复合系统中核桃细根根长的垂直分布重心深度为35.49 cm，比核桃单作（29.97 cm）下移了5.52 cm；水平径向的分布重心为距树干基部0.91 m，比核桃单作（0.99 m）向树干基部靠近了0.08 m。复合系统中小麦根长的分布重心深度为18.46 cm，比小麦单作（26.04 cm）上移了7.58 cm。②复合系统中核桃细根的平均根长密度为83.6 cm/dm3，比核桃单作（135.6 cm/dm3）降低了38%；复合系统中小麦根长密度为1.74 cm/cm3，比小麦单作（1.22 cm/cm3）增加了42%。③复合系统中核桃细根的平均比根长在0～30 cm土层为5 149.34 cm/g，大于核桃单作（3 624.68 cm/g），而在30～100 cm土层为2 626.59 cm/g，小于核桃单作（3 906.9 cm/g）；复合系统中小麦比根长在0～50 cm土层为10 019.5 cm/g，小于小麦单作（11 811.7 cm/g）；在50～100 cm土层为14 328.9 cm/g，大于小麦单作（13 389.6 cm/g）。【结论】复合系统中0～30 cm土层及水平径向距树干基部1.5～2.0 m是根系竞争最剧烈的区域，为了适应复合系统的地下竞争，核桃和小麦在生长过程中对细根的空间分布及形态产生了可塑性反应。 |
| 关键词: 农林复合系统 细根 种间关系 根系分布 根系形态 |
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| 基金项目:国家“十二五”科技支撑计划项目“高效可持续农林复合系统构建及调控技术研究”（2011BAD38B0202） |
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| Spatial distribution and morphological variations of the fine roots in walnut-wheat intercropping agroforestry ecosystem |
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| Abstract: |
| 【Objective】This paper studied the distribution patterns and morphological variations of fine roots in walnut (Juglans regia)-wheat(Triticum aestivum) agroforestry system to provide theoretical basis for the interspecific relationship research and management of agroforestry ecosystem.【Method】With walnut,wheat monocropping ecosystem as control,samples were collected by soil coring method.WinRHIZO root analysis system was conducted to measure root morphology parameters.Moreover,differences of the fine roots spatial distribution and morphological variations between the agroforestry ecosystem and monocropping ecosystem were analyzed.【Result】①The vertical gravity center of walnut fine root length in agroforestry ecosystem is 35.49 cm,compared with that in walnut monocropping ecosystem,which is 29.97 cm,moving down 5.52 cm.The distance between the radial gravity centers of walnut fine root length and the tree in agroforestry ecosystem is 0.91 m,which is 0.08 m closer to the tree than that (0.99 m) of walnut in monocropping ecosystem.The vertical gravity center of wheat root length in agroforestry ecosystem is 18.46 cm,compared with that in wheat monocropping ecosystem,which is 26.04 cm,moving up 7.58 cm.②The total mean root length density of walnuts in agroforestry ecosystem is 83.6 cm/dm3,which is 135.6 cm/dm3 in walnut monocropping ecosystem.The former decreases 38% than the latter.The total mean root length density of wheat in agroforestry ecosystem is 1.74 cm/cm3,which is 1.22 cm/cm3 in wheat monocropping ecosystem.The former increases 42% than the latter.③In 0-30 cm soil depth,the specific root length of walnut is 5 149.34 cm/g in agroforestry ecosystem,which is greatter than 3 624.68 cm/g in walnut monocropping ecosystem.But in 30-100 cm soil depth,the specific root length of walnut is 2 626.59 cm/g in agroforestry ecosystem,which is smaller than the 3 906.9 cm/g in walnut monocropping ecosystem;In 0-50 cm soil depth,the specific root length of wheat is 10 019.5 cm/g in agroforestry ecosystem,smaller than the 11 811.7 cm/g in wheat monocropping ecosystem.In 50-100 cm soil depth,the specific root length of wheat is 14 328.9 cm/g in agroforestry ecosystem,greatter than the 13 389.6 cm/g in wheat monocropping ecosystem.【Conclusion】In agroforestry ecosystem,most of the root competitions appear in 0-30 cm soil depth and radial 1.5-2.0 m to the tree.As responses to adapt to the competition and maximize access to resources in soils in agroforestry systems,the spatial distribution and morphology in fine roots might have a high plasticity during the growth of walnut and wheat. |
| Key words: agroforestry fine root interspecific relationship root spatial distribution root morphology |
