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植物通过维系根长密度的大小及其分布格局逐渐优化资源利用格局。本实验在祁连山地建立禾本科牧草燕麦与豆科毛苕子混播草地,按燕麦(Avena sativa)与毛苕子(Vicia villosa)的密度比例设置CK1(0:10)、Ⅰ(6:4)、Ⅱ(5:5)、Ⅲ(4:6)、Ⅳ(2:8)和CK2(10:0)6个密度组,研究了混播草地燕麦与毛苕子根系根长密度的空间分布格局。结果表明:混播草地燕麦和毛苕子根长密度显著大于单播处理,并且随着混播草地中燕麦密度的减小,牧草根长密度逐渐增大,出现高燕麦密度低根长密度的现象;在空间分布上燕麦和毛苕子根长密度表现出明显差异,燕麦根系主要分布在0～25cm土层,毛苕子根系主要分布在0～15cm土层。根系的分层分布改变了其竞争格局,垂直分布上出现的差异使根系结构和形态逐渐发生转变,混播处理使Ⅰ、Ⅱ、Ⅳ处理的主根生长受到抑制,5个处理的侧根生长受到促进。一年生牧草侧根在空间上的分层分布改变了混播草地的资源利用格局,逐渐优化了根长密度配置格局,实现了土壤资源利用最大化的目标。
Plants optimize the pattern of resource utilization by maintaining the size and distribution pattern of root length density. In this study, grassland gramineous oat and legume ramie mixed grassland were established in Qilian Mountains. According to the density ratio of Avena sativa to Vicia villosa, CK1 (0:10), Ⅰ (6: 4), Ⅱ (5 The spatial distribution pattern of root length density of oat and barley seedlings was studied in six densities of 5 (superscript Ⅲ), Ⅲ (4: 6), Ⅳ (2: 8) and CK2 (10: 0) The results showed that the root length of oat and hazelnut in mixed-sown grassland was significantly higher than that in uniaxial sowing. With the decrease of oat density in mixed-sown grassland, the long-root density of forage grass gradually increased, The distribution of oat and hazelnut root length density showed significant differences, oat root distribution mainly in 0 ~ 25cm soil layer, hairy root distribution mainly in 0 ~ 15cm soil layer. The stratification of root system changed its competition pattern. The difference in vertical distribution changed the structure and shape of roots gradually. The growth of main roots of Ⅰ, Ⅱ and Ⅳ was inhibited by mixed sowing treatment and the growth of lateral roots of 5 treatments was promoted. The spatial distribution of lateral roots of annual grasses changed the pattern of resource utilization in mixed-sown grasslands and gradually optimized the configuration of root-length density and achieved the goal of maximizing the utilization of soil resources.