青藏高原公路两侧草地土壤种子库特征研究——以国道214公路共玉公路段为例

A Study on the Characteristics of Soil Seed Bank of Grassland on Roadsides of Qinghai-Tibet Plateau-Take the Highway of G214 for Example

为研究公路建设中土壤种子库的保护与利用策略,以青藏高原G214公路共玉段为例,研究春与秋季公路两侧不同距离、群落类型与覆盖度的土壤种子库物种组成、垂直分布及种子库密度。研究结果表明,研究区土壤种子库属于瞬时种子库,盐碱滩、退化草地、典型草原3种植被类型的土壤种子库密度在173~1 837粒·m-2之间,植被类型间差异显著;距离公路越远土壤种子库物种数和种子库密度越大;土壤种子库土壤表层0~5cm范围内占到总数的85.4%;春季土壤种子库萌发密度和物种数大于秋季土壤种子库;大多萌发种类尚无法实现人工规模化生产。基于研究结果,我们建议该区域在公路建设中结合表土剥离,着重加强典型草原种子库的薄层表土保护与利用,并尽量在春季进行剥离施工,在恢复利用时考虑补充外源种子。

To study the strategy of soil seed bank during highway construction,taking the section of Gonghe to Yushu of G214 national highway on the Qinghai-Tibetan Plateau as example,we carried the research of species composition,vertical distribution and seed density of soil seed bank for different distance from road and community type.The results shows that the seed bank belongs to the temporal type;soil seed density for 3 vegetation types including salina,degraded steppe,typical steppe are between 173~1 837 grains·m-2,with significant differences among vegetation types;the farther is the distance from the road,the more abundant is the species and density of soil seed bank;in the upper range of 0~5 cm in the soil,seed bank accounted for 85.4% of the total;species abundance and density of soil seed bank germinated in spring is greater than in the autumn;most of the species germinated are still unable to achieve a large-scale artificial production.Based upon the result,we suggest the region should focus on strengthening and incorporating the protection and utilization of thin topsoil in typical steppe for topsoil stripping,and which should be better stripped in the spring and exogenous seeds should be also take into account in restoration.