广西岩溶石山飞机草种群的繁殖特征

对广西岩溶石山3个典型群落(飞机草优势群落、黄荆条-飞机草混合群落和类芦-蔓生莠竹群落)中飞机草(Eupatorium odoratum)种群的繁殖特征进行了研究.结果表明:3个群落中飞机草的头状花序数为520～3281个m-2；种子产量为12941～74386粒m-2；头状花序的平均种子数为22～25粒；种子千粒重为...

Reproductive Characteristics of Eupatorium odoratum Populations in Karst Rocky Mountain in Guangxi

The reproductive characteristics of Eupatorium odoratum population in three typical communities, such as E. odoratum community (dominancy community), Vitex negundo-E. odoratum community (mixed community), and Neyraudia reynaudiana -Microstegium vegans community (concomitant community), were studied in karst rocky mountain in Guangxi. The results showed that the number of capitulum of E. odoratum in 1 square meter ranged from 520 to 3281, and seed yield from 12941 to 74386 grains m^-2, each capitulum produced 22 to 25 seeds and the 1000-seed-weight ranged from 0.17 to 0.19 g. The number of capitulum and seed yield per individual in mixed community were significantly different from those in concomitant community, but there were not significant difference between dominant community and two another communities. There was a positive correlation between individual seed yield and plant height, as well as biomass. Seed yield in unit area was positively correlated with the number of flowering plants and capitulum, but was weakly correlated with coverage. In the three communities in arid karst rocky mountain, E. odoratum could produce a large number and light seeds, it indicated that E. odoratum had strong reproductive capacity and displayed strong invasive, and it also could choose the corresponding reproductive strategy according to the environment change, so that it could adapt to environment at large scale.