Effects Of Dififerent Local Density On Reproductive Success In Circaeaster Agristis Maxim

Circaeaster agristis Maxim as an annual herb, is a national secondary protection plant, due to its special habitat requirements, the distribution is limited. Characters of different population such as population size, density are different, and so is the local density, the individuals are affected by the surrounding plants, and the reproductive success is different. Investigated the reproductive success of twelve C. agristis populations which were distributed in the wanglang national nature protection zone, and choose35individuals randomly from each populations, observe its flower number, seed number and calculate the fruit set rate, determine the distance between individuals and adjacent the first plants (N1), and the average distance between first and second plants(N2), the average distance between first, second, third plants (N3), and count the number of individuals among10cm(D1), the number of individuals within the circle of10cm to20cm(D2), the number of individuals within the circle of20cm to30cm(D3), understand how the flower number, seed number and fruit set rate of individuals affected by conspecific in different populations, investigate the influence mechanism of C. agristis reproductive success, so we can provide scientific reference for the protection of C. agristis, the analysis results are as follows:(1)The flower number of individuals were not significantly affected by N1, but affected significantly by N2、N3, which shows that the flower number of individuals were not only affected by the distance between adjacent plants, but also associated with adjacent plant number; D1affected the flower number of individuals significantly, but D2、D3were not, this shows the regular pattern that the number of flowers increased with the local density at a certain range, but the regular was not exist when expanded the certain extent; The number of flowers were significantly different in populations.(2)Analysis of seed number and fruit set of individuals shows that the seed number was significantly influenced by N2、N3、D1, and N1、D2、D3on its influence was not significant, this may be the same as the impact mechanism of individual flower number, the seed number was influenced by both the adjacent plant number and spacing, and the local density impact on the number of individual fruit within a certain range; The fruit set rate of individual was affected by N1、 N2、N3、D1significantly, D2、D3on its influence was not significant, the reason may be that the fruit set was affected by both flower number and seed number of individuals, and apply to the adjacent plant number and spacing, the local density of individual effects occur within a certain range; The seed number and fruit set of individuals were different in populations. (3)Individual flower number affected the seed number and fruit set significantly, and so was the dynamic between different populations, which may due to the habitat conditions and restriction mechanism of C. agristis. The mating system of C. agristis is likely to be self-incompatibility, so if the individual output more flowers, its formation potential of the fruit is more possible and will have higher fruit set rate. with different habitat conditions, the reproduction of individual will be different.