【作者】 魏茶花；

【导师】 张荣；

【作者基本信息】 兰州大学 ， 生态学， 2008， 硕士

【摘要】 本研究采用人工种植杂草代替杂草自然入侵的方法,通过固定样方动态的观测与调查,研究人工种植杂草对具有不同竞争能力的两种小麦、土壤水分的影响以及杂草地上生物量和多度变化。种子萌发实验结果表明:不同植物种子的萌发所需要的生态因子存在差异,冷湿层化、光照条件及温度变幅能够影响黄土高原植物种子的发芽率。其中,冷湿层化对7种植物的发芽率有显著的影响,光照条件对10种植物有显著的影响,温度变幅处理对8种植物有显著的影响,然而芨芨草(Achnatherum splendens)、打碗花(Calyategia hederacea)和披针叶黄华(Thermopsis lanceloata)这3种植物种子对这三因子没有显著响应。人工种植杂草实验结果表明:1.杂草对现代品种定西-24的出苗率、株高、收获指数和千粒重有明显的抑制作用,杂草的侵入使传统地方品种和尚头的无效分蘖数减少,而其它方面的影响不太明显;2.定西-24的平均收获指数高于和尚头,但杂草的入侵使定西-24的收获指数下降,而对和尚头的影响不大;3.表层土壤水分含量在生长前期变化不大,而成熟期时,有大量生长杂草的处理其含量比少量生长杂草处理的高;4.在小麦生长前期,不论有无添加杂草的处理,各处理均有杂草生长,其种类数和总株数变化不大,而生长后期,有添加杂草的处理,其杂草种类数和总株数明显增加,并明显超过不添加杂草的处理;5.杂草在麦地的成功建植与是否添加杂草、小麦品种及其密度处理有很大的关系。五月份时,有许多非人工种植的杂草物种入侵麦地,且添加杂草处理、小麦品种及其密度对这些物种都具有显著性影响。七月份时,是否添加杂草处理对打碗花、野燕麦、蝇虫实和狗尾草的建植有显著性影响。添加杂草处理中,上述物种的多度明显高于不添加杂草处理的。更多还原

【Abstract】 We observed and investigated the performance of sowing seeds instead of natural invasion on fixed quadrants for the purpose of researching on the effect of invasion of weeds on different completive ability of two spring wheat, the soil water and aboveground biomass and abundance of weeds.The results showed that germination niche or requirements for germination, varied among plant species in the Loess plateau. The results showed that cold-wet stratification, light and temperature fluctuation affected the germination percentage of plant species. Cold-wet stratification had significant effect on 7 plant species; light had significant effect on 10 plant species; temperature fluctuation affected 8 plant species significantly. But Achnatherum splendens、Calyategia hederacea、Thermopsis lanceloata did not respond to any factor or the combination of factors.Our field result indicated that: 1.Weeds inhibited the seedling emergence rate, plant height, harvest index and 1000-seed weight of Dingxi-24 significantly. The successful invasion reduced the ineffective tiller number of Heshangtou, but have no much effect on other aspects. 2. The average harvest index of Dingxi-24 as higher than Heshangtou, but the invasion of wheat decreased the harvest index of Dingxi-24 and had no effect on Heshangtou. 3. The soil water is no significant difference at the early growth stage. However, the soil water in treatment area is higher than the control. 4. Wheher sowing weed or not, there were weeds and the varieties and number did not vary a lot at early growth stage to booting stage. However, the varieties and number increased greatly in sowing area at the late growth area. 5. The successful establishment of weeds is correlated with the sowing of weeds, wheat cultivars and wheat density. The treatment of sowing, wheat cultivars and wheat density had significant effect on those species after the invasion of weeds in May. Invasion of weeds had significant effect on the establishment of Calyategia hederacea、Avena fatua、Corisermum declinatum、Setaria viridis. And the abundance of those species is higher than those of control.更多还原