Studies On Reproductive Ecology Of Quercus Variabilis Population

On the basis of geographical distribution and ecological property studies, the law of Q. variabilis reproductive activities and process and the relationship with the environment was discussed in the thesis.The research locality was at Haoping (Mei county), Louguantai (Zhouzhi county), Nanwutai (Chang'an county ), all in Shaanxi province. 18 plots of 20m X 20m were established in 6 type association and the research work was carried out with the change of phenology.The thesis contained: geographical distribution and ecological property, reproductive age, reproductive phenology, reproductive module(flower, fruit and nut), the shape and resident of seedlings, the influence of mother body to the budding seedlings, the comparison of different asexual means and sexual and asexual reproduction, the reproductive ability.Conclusions:1.Biological and ecological properties were the basis of geographical distribution and the latter greatly influenced the former. With good adaptability, Q. variabilis was not strict with soil, moisture, temperature and so on and distributed in 22 provinces, cities and districts in China. The distribution center was located at Qinling Mountain-Dabieshan Mountain and Shaanxi province was a typical distribution region. Though community analysis, Q. variabilis forest in Shaanxi province could be divided into 6 type association.2.The reproductive age was mainly decided by the heredity factors. The environmental factors could play modification effect at some extent on plants to adapt to different environmental press. Sunlight, soil and moisture were the key factors.3. The reproductive phenology was mainly influenced by temperature and sunlight. The dynamics of reproductive module was mainly decided by the biological properties. They started the first reproductive activity at 9a and 40-100a was the best. The key environmental factors are sunlight, soil and moisture. On the application of life table theory, the life table of reproductive module was accomplished. The life table described the key phase of reproductive dynamics process and carried forward the population dynamics to module level. The shape and resident of seedlings were the last and key phase of Q. variabilis reproduction. The key environmental factor influencing the sexual reproduction of Q. variabilis sunlight and the activity of human and animals also played an important role.4.The asexual reproductive ability of Q. variabilis was the result of inner and outer factors co action. It showed a lower-higher-lower trend with increase of DBH. The duding ability of the root was stronger, so the stump should be as low as possible and could not overpass SOcm.Sunlight was the key factor influencing budding ability and the survival of seedlings. Among 3 type asexual reproductive means, the contribution ratio of stump was the most and the property of the seedlings was also the best. The contribution ratio of asexual was more than that of sexual and seedlings of former were better than the latter. But the significance of sexual reproduction was the maintenance and enhancement of the heredity diversity of Q. variabilis.S.Though the analysis of reproductive ability and reproductive value, Q. variabilis population was fairly stable and could realize the regeneration after a generation. The reproductive value showed a lower-higher-lower trend, which showed the correlation between the reproductive contribution and age.