农林复合系统论文：渭北几种农林复合模式对林木和作物根....doc

农林复合系统论文：渭北几种农林复合模式对林木和作物根系的影响【中文摘要】研究核桃(Juglans regia)与小麦(Triticum aestivum)、油菜(Brassica campestris)和大豆(Glycine max)三种复合系统中细根的空间分布及形态变异,为种间关系研究及农林复合系统的合理设计提供依据。采用根钻法取样,用WinRHIZO根系分析系统对根系形态进行分析,比较复合系统与单作细根的空间分布和形态差异。主要研究结果如下:1.核桃-小麦复合系统中核桃细根根长密度为83.6 cm/dm3,小于核桃单作的135.6 cm/dm3,降低了38%;复合系统中小麦根长密度为1 736.7 cm/dm3,比小麦单作的1 223.3 cm/dm3增加了42%。核桃-油菜复合系统中核桃细根根长密度为95.67 cm/dm3,小于核桃单作的113.43 cm/dm3,降低了15.7%;复合系统中油菜根长密度为321.33 cm/dm3,大于油菜单作的316.39 cm/dm3。核桃-大豆复合系统中核桃细根根长密度为120.67 cm/dm3,略大于核桃单作的118.57 cm/dm3;复合系统中大豆根长密度为275.09 cm/dm3,小于大豆单作的378.66 cm/dm3,减少了27.3%。2.核桃-小麦复合系统中核桃细根根长的垂直分布重心深度为35.49 cm,比核桃单作的29.97 cm,向下移动了5.52 cm;复合系统中核桃细根的水平径向分布重心距树干基部0.91 m,比核桃单作0.99 m,向树靠近了0.08 m;复合系统中小麦根长的分布重心深度为18.46 cm,比小麦单作的26.04 cm,向上移动了7.58 cm。核桃-油菜复合系统中核桃细根根长的垂直分布重心深度为36.50 cm,大于核桃单作的31.90 cm,向下移动了4.60 cm。复合系统中核桃细根的水平径向分布重心为距树0.86 m,小于核桃单作的0.97 m,向树靠近了0.11 m;复合系统中油菜根长的分布重心深度为19.90 cm,比油菜单作的25.10 cm,向上移动了5.2 cm。核桃-大豆复合系统中核桃细根根长的垂直分布重心深度为31.7 cm,大于核桃单作的25.55 cm,向下移动了6.2 cm;复合系统中核桃细根的水平径向分布重心为距树0.96 m大于核桃单作的0.93 m,离树距离增加了0.03 m;复合系统中大豆根长的平均分布重心深度为19.50 cm,大于大豆单作的15.00 cm,向下移动了5.5 cm。3.核桃-小麦复合系统中核桃细根平均直径在030 cm土层内为0.314 5 mm,小于核桃单作的0.356 7 mm。复合系统中核桃细根比根长在030 cm土层为51.49 m/g,大于核桃单作的36.23 m/g;而在30100 cm土层为26.27 m/g,小于核桃单作的39.07m/g。在050 cm土层内核桃-小麦复合系统小麦细根平均直径为0.295 5 mm,大于小麦单作的0.272 0 mm。复合系统中小麦比根长在050 cm土层为100.20 m/g,小于小麦单作的118 12 m/g;在50100 cm土层为143.29 m/g,大于小麦单作的133.90 m/g。核桃-油菜复合系统中复合系统核桃细根平均直径0.355 9 mm,小于核桃单作的0.372 2 mm。复合系统比根长为40.90 m/g,略大于核桃单作的37.67 m/g。复合系统油菜细根平均直径为0.205 9 mm,大于油菜单作的0.183 3 mm。复合系统油菜比根长为156.98 m/g ,小于油菜单作的211.95 m/g。核桃-大豆复合系统中核桃细根平均直径0.316 8 mm,略大于核桃单作的0.265 8 mm;复合系统核桃细根比根长为48.98 m/g,小于核桃单作的68.97 m/g。复合系统大豆细根平均直径为0.254 9 mm,大于大豆单作的0.222 0 mm。复合系统大豆细根比根长为102.98 m/g,小于大豆单作的135.06 m/g。4.核桃-小麦、核桃-油菜、核桃-大豆三种复合系统均降低了土壤含水率,总体上三者水分状况相比较:核桃-大豆核桃-油菜核桃-小麦。综上所述,在复合系统根系竞争中,强势竞争者在剧烈竞争区域以增加细根直径减小比根长,弱势竞争者则以减小细根直径增大比根长的趋势来适应竞争的。复合系统中030 cm土层及水平径向距树干基部0.51.5 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和最大限度的获取土壤中的资源,核桃及间作物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。【英文摘要】Distribution patterns and morphological variations of fine roots in walnut (Juglans regia)-wheat (Triticum aestivum), walnut-rape (Brassica campestris) and walnut-soybean (Glycine max) agroforestry systems were studied, which provided theoretical basis for the interspecific relationship research and management of agroforestry ecosystem. 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. The main results were below:1. In walnut-wheat agroforestry ecosystem, the mean fine root length density of walnuts in agroforestry ecosystem is 83.6 cm/dm3, less than in walnut monocropping ecosystem (135.6 cm/dm3), reduced by 38%. The mean fine root length density of wheat in agroforestry ecosystem is 1 736.7 cm/dm3, more than in wheat monocropping ecosystem (1 223.3 cm/dm3), increased by 42%. In walnut-rape agroforestry ecosystem, the mean fine root length density of walnuts in agroforestry ecosystem is 95.67 cm/dm3, less than in walnut monocropping ecosystem (113.43 cm/dm3), reduced by 15.7%. The mean fine root length density of rape in agroforestry ecosystem is 321.33 cm/dm3, more than in rape monocropping ecosystem (316.39 cm/dm3), increased by 1.6%. In walnut-soybean agroforestry ecosystem, the mean fine root length density of walnuts in agroforestry ecosystem is 120.67 cm/dm3, more than in walnut monocropping ecosystem (118.57 cm/dm3). The mean fine root length density of soybean in agroforestry ecosystem is 275.09 cm/dm3, less than in soybean monocropping ecosystem (378.66 cm/dm3), reduced by 27.3%.2. In walnut-wheat agroforestry ecosystem, the vertical gravity center of walnut fine root length in agroforestry ecosystem is 35.49 cm, compared with that in walnut monocropping ecosystem(29.97 cm), move 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 closer 0.08 m to the tree than that walnut monocropping ecosystem(0.99 m). The veridical gravity center of wheat root length in agroforestry ecosystem is 18.46 cm, compared with that in wheat monocropping ecosystem(26.04 cm), move up 7.58 cm. In walnut-rape agroforestry ecosystem, the vertical gravity center of walnut fine root length in agroforestry ecosystem is 36.50 cm, compared with that in walnut monocropping ecosystem(31.90 cm), move down 4.60 cm. The distance between the radial gravity centers of walnut fine root length and the tree in agroforestry ecosystem is 0.86 m, which is closer 0.11 m to the tree than that walnut monocropping ecosystem(0.97 m). The veridical gravity center of rape root length in agroforestry ecosystem is 19.90 cm, compared with that in rape monocropping ecosystem(25.10 cm), move up 5.2 cm. In walnut-soybean agroforestry ecosystem, the vertical gravity center of walnut fine root length in agroforestry ecosystem is 31.7 cm, compared with that in walnut monocropping ecosystem(25.55 cm), move down 6.2 cm. The distance between the radial gravity centers of walnut fine root length and the tree in agroforestry ecosystem is 0.96 m, which is away 0.03 m from the tree than that walnut monocropping ecosystem(0.93 m). The veridical gravity center of soybean root length in agroforestry ecosystem is 19.50 cm, compared with that in soybean monocropping ecosystem(15.00 cm), move down 5.5 cm.3. In walnut-wheat agroforestry ecosystem, the mean fine root diameter of walnut in the 0 30 cm soil layer was 0.314 5 mm in agroforestry ecosystem, is smaller than 0.356 7 mm in walnut monocropping ecosystem. In 030 cm soil layer, the specific root length of walnut is 51.49 m/g in agroforestry ecosystem, is greatter than the 36.23 m/g in walnut monocropping ecosystem, but in 30100 cm soil layer, the specific root length of walnut is 26.27 m/g in agroforestry ecosystem, is smaller than the 39.07 m/g in walnut monocropping ecosystem.The mean fine root diameter of wheat in the 0 50 cm soil layer was 0.295 5 mm in agroforestry ecosystem, is greater than 0.272 0 mm. in wheat monocropping ecosystem.In 050 cm soil layer, the specific root length of wheat is 100.20 m/g in agroforestry ecosystem, is smaller than the 118 12 m/g in wheat monocropping ecosystem. In 50100 cm soil layer, the specific root length of wheat is 143.29 m/g in agroforestry ecosystem, is greatter than the 133.90 m/g in wheat monocropping ecosystem.In walnut-rape agroforestry ecosystem, the mean fine root diameter of walnut in agroforestry ecosystem is 0.355 9 mm, smaller than 0.372 2 mm in walnut monocropping ecosystem. The specific root length of walnut in agroforestry ecosystem is 40.90 m/g, is greatter than the 37.67 m/g in walnut monocropping ecosystem. The mean fine root diameter of rape in agroforestry ecosystem is 0.205 9 mm, greater than 0.183 3 mm in rape monocropping ecosystem. The specific root length of rape in agroforestry ecosystem is 156.98 m/g, is smaller than the 211.95 m/g in rape monocropping ecosystem.In walnut-soybean agroforestry ecosystem, the mean fine root diameter of walnut in agroforestry ecosystem is 0.316 8 mm, greatter than 0.265 8 mm in walnut monocropping ecosystem. The specific root length of walnut in agroforestry ecosystem is 48.98 m/g, is smaller than the 68.97 m/g in walnut monocropping ecosystem. The mean fine root diameter of soybean in agroforestry ecosystem is 0.254 9 mm, greater than 0.222 0 mm in soybean monocropping ecosystem. The specific root length of soybean in agroforestry ecosystem is 102.98 m/g, is smaller than the 135.06 m/g in soybean monocropping ecosystem.4. Walnut - wheat, walnut - rape, walnut -soybean three agroforestry ecosystem, are all decreased soil water content, comparing the three agroforestry ecosystem water conditions: walnut - soybean walnut - rape walnut - wheat.In summary, root competition in agroforestry ecosystem, the strong competitors depend on increase the fine root diameter and decreased specific root length to adapt to competition in the highly competitive area. On the contrary, the weak competitors tendency to decreased fine root diameter and increased specific root length to adapt to competition. In agroforestry ecosystem, most of the root competitions appeared in 030 cm soil layer and radial distance 1.52.0 m from the tree. As responses to adapt to the competition and maximize to 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.【关键词】农林复合系统 细根 种间关系 根系分布 根系形态【英文关键词】agroforestry fine root interspecific relationship root spatial distribution root morphology【目录】渭北几种农林复合模式对林木和作物根系的影响摘要5-7ABSTRACT7-9第一章 文献综述12-211.1 引言121.2 研究的目的和意义12-141.3 农林复合生态系统的发展概况14-191.3.1 概