Effect of species diversity on invasion risk of introduced forage plants

通过野外调查和田间试验，了解物种多样性对引进牧草入侵风险的影响。1.这片草原一直保持着作为栖息地的本土马，是我国的国家古迹之一。几年前，小睦冈和小木山是由本地植物，如结缕草占主导地位。小牧丘草地经历了12年多的由原生草地向外来草地的演变。但是，Ougiyama没有改变。2.外来草不能在物种丰富度高、本地植物密度高的花盆中生长。3.荻山有丰富的匍匐植物基因型。这些基因型对裸地具有较高的再覆盖能力，可以有效地防止外来牧草的入侵。

The object of this study is to know the "Effect of species diversity on invasion risk of introduced forage plants" through field survey and field experiments. 1. This grassland has been maintained as habitat of native horse that is one of national monument of our country. Few years ago, Komatugaoka and Ougiyama was dominated by native plants such as Zoysia japonica. Komatugaoka changed from native grass to alien grass dominated grassland for over 12years. But, Ougiyama was not changed. 2. The alien grass can't grow in a pot of high species richness and high density of native plant. 3. There are rich creeping genotypes of native plants in Ougiyama. These genotypes would prevent invasion risk of introduced forage plants because these genotypes have high re-covering ability of bare land.