Abstract
The Sasa nipponica community developed after felling forest was suppressed by several disturbing methods, and was oversown with Zoysia japonica seeds contained in the cattle dungs. In the first study, the establishment and survival of Zoysia japonica seedling were examined on the following four disturbance treatment plots: (i) the Sasa community was removed and cultivated ; (ii) burned ; (iii) grazed ; and (iv) undisturbed. 1) In the next year of the treatments, the stands of cultivating plot, burning plot, grazing plot, and undisturbing plot were dominated by Chenopodium album, Erigeron spp., Artemisia princeps and Sasa nipponica, respectively. 2) The establishment of Zoysia japonica seedling on the cultivating plot was better than that on the other plots under the rotational grazing. The numbers of seedling on the undisturbing plot were markedly reduced. 3) Although many seedlings were destroyed by the rotational grazing, the seedlings on the cultivating plot more by the deferred grazing. But on the undisturbed plot, such a deferred grazing was not effective on the survival. In the second study, the Sasa nipponica community was surppressed by heavy and light grazing pressures in the year before sowing of Zoysia japonica. 1) In the next year of the grazing treatments, the stand of light grazing plot was dominated by Sasa nipponica. However, the stand of heavy grazing plot was more invaded by Erigeron spp.. 2) The establishment of seedling on the heavy grazing plot was significantly better than that on the light grazing plot. Such a difference was maintained till the next spring. 3) Although the application of N-P-K fertilizer increased the growth of Chenopodium album or annual grass weeds, it had no effect on the establishment of Zaysia japonica seedling. Based on the above results, it was concluded that for success in the establishment of seedling of Zoysia japonica on the Sasa community developed after felling forest, Zoysia japonica seed shoued be sown after disturbing of the Sasa community allowed waste type weeds such as Erigeron spp. to invade.
