土壤种子库萌发实验在野外与室内的对比分析

Comparative Analysis on Germination of Soil Seed Bank in Field and Laboratory

实验室萌发法是目前国内外研究土壤种子库时普遍采用的方法,而实验室与野外自然环境在萌发条件上具有很大的差异,在野外进行萌发实验是否对土壤种子库恢复潜力的估计更具有可靠性？鉴于此,我们在塔里木河下游选择了3个典型断面,分别在野外和实验室进行了土壤种子库萌发实验。结果表明：①野外与实验室萌出的物种相同,但幼苗密度在野外（598.8株·m^-2）明显高于实验室（530.3株·m^-2）。②物种组成中,豆科物种在野外实验幼苗密度明显较高;若以生活型划分,多年生草本和灌木幼苗密度在野外明显高于实验室。③各物种在野外和实验室的萌发特征相似,但在实验室萌发速度较快,萌发高峰期提前了2～3 d。综合来看,对于塔里木河下游土壤种子库的研究,在野外进行萌发实验其结果更具有可靠性。这对今后土壤种子库的研究具有参考意义。

Seedling-emergence in laboratory is a common method to study the potential of restoration of soil seed bank. However, the germination conditions are different in laboratory and natural environment. To give scientific evidence to choose method on study of soil seed bank, the paper operated germination of soil seed bank in both field and laboratory. The following results have been obtained： ①There is no difference between species, but the seedling density in field （598.8 plants, m^-2） is larger than that in laboratory （530. 3 plants m^-2）. ②In species composition, the seedlings density of Leguminosae species is obviously higher in field experiment than in laboratory experiment. In life form composition, the seedling density of perennial herbaceous and shrub-and-subshrub in field experiment is larger than in laboratory experiment. ③Every species has similar germination characteristics in field and laboratory＇s experiments. The speed of germination was fast in laboratory than in field and the germination climax period advance by 2 to 3 days in laboratory experiment than in field. In conclusion, it is better for germination experiment of soil seed bank in natural conditions, which will be a reference for the study of soil seed bank in other arid regions .