白三叶和狗牙根混播群落3年间地上生物量和种间竞争的动态

采用2种牧草总密度保持不变而组成种比例在0～1变化的替代试验法,设白三叶100%(A)、白三叶75%+狗牙根25%(B)、白三叶50%+狗牙根50%(C)、白三叶25%+狗牙根75%(D)、狗牙根100%(E)5种处理,研究混播组合播种后3年的地上生产力和种间竞争动态.结果表明:建植第1年,3种混播组合的地上生物量高于...

DThree year study of above-ground biomass and interspecific competition ofTrifolium repens and Cynodon dactylon mixed community

From 2005 to 2007, mixed community of white clover and bermudagrass were observed to investigate the above-ground biomass and inter-specific competition dynamics of the mix-sowed forage grasses. With the total density of the forage grasses unchanged, five seeding treatments were carried out, namely, treatment A (white clover, 100%), treatment B (white clover, 75%; bermudagrass, 25%), treatment C (white clover, 50%; bermudagrass, 50%), treatment D (white clover, 25%; bermudagrass, 75%) and treatment E (bermudagrass, 100%). The results indicated the aboveground biomass of the 3 mixture treatments (B , C and D ) were all higher than that of treatment A (2.078 kg/m2), but less than that of treatment E (4.406 kg/m2) in 2005 and the yields of 3 mixture treatments were all higher than that of treatments A and E in 2006 and 2007. The aboveground biomass of treatment C was the maximum (17.721 kg/m2) and was significantly different from other treatments (P<0.05) in 3 years. During the trial, white clover was the main grass in the early period of the each year. And in this period of time white clover and bermuda grass occupied different ecological niches and showed a symbiotic relationship with the competitive ability of white clover stronger than that of bermuda grass. Then, bermuda grass gradually became the main grass in all mixed grassland and the 2 forage grasses showed antagonistic action and the competitive ability of bermuda grass was stronger than that of white clover. At last, Bermuda grass became the dominant species of the mixed community.