Effects of soil extracts from the first and second generation of Pinus massoniana stands on seed germination and seedling growth

Pinus massoniana seedlings were treated with different concentrations of soil extracts from the first and second generation of P.massoniana stands.The results indicate that each concentration level of soil extracts had obvious differences in seed germination.The lower the concentration was,the higher the germination rate and germination energy were.The aqueous extracts from replant soil had no significant effect on seed germination.When the concentration was 1︰20 of soil extracts from the first generation of P.massoniana forests,the growth of seedling was better than other treatments.And when the concentration was 1︰10 from the second generation,the seedlings grew best.Even so,there were no significant effects on seedling growth with the concentration of soil extracts and the generation of successive planting.The results of germination experiments show that there was no obvious autotoxicity of P.massoniana when the second generation of P.massoniana was replanted.