【摘要】 明确土壤种子库在海拔梯度上的变化规律,可为人工边坡的拟自然恢复提供参考。本文选取川西高山亚高山区为研究对象,通过野外样方调查和室内种子库萌发实验,研究了该区域自然边坡的土壤种子库组成、土壤种子库与植被群落关系及其随海拔梯度的变化。结果发现:(1)不同海拔区域自然边坡土壤种子库的物种组成与物种多样性有较大差异。随着海拔的上升,土壤种子库中一年生草本植物的物种占比逐渐降低,多年生草本植物则逐渐增加。种子库的物种多样性则随着海拔上升呈先增加后下降的变化规律。(2)海拔及坡位都对土壤种子库的密度有一定影响。低海拔地区土壤种子库的平均种子密度一般高于高海拔地区。同一边坡下坡位土壤种子库的种子密度高于中、上坡位。(3)区域内自然边坡土壤种子库和植被群落物种组成的相似程度不高,且随着海拔的升高,相似系数逐渐降低。研究表明,海拔是影响土壤种子库物种组成及密度的重要因素,该区域边坡的生态恢复需根据海拔梯度选择适宜物种人工构建种子库。更多还原

【Abstract】 To clarify the variations of soil seed banks along the elevation gradient and provide reference for imitating natural restoration of artificial slopes,the alpine and sub-alpine areas in the Western Sichuan was selected as the research objects in this paper. The composition of soil seed banks,relationship between soil seed banks and vegetation of natural slopes,and their changes with altitude gradient were studied by field plot investigations and germination experiments. The results showed that:( 1) the species composition and species diversity differed significantly among soil seed banks collected from different altitude natural slopes. The proportion accounting for by the annual herbaceous plants gradually decreased with the increasing altitude in the soil seed banks,meanwhile the proportion accounting for by the perennial herb gradually increased. The species diversity of soil seed bank increased first and then decreased with the increase of altitude.( 2) Elevation and slope position had a certain impact on the density of soil seed bank. The average seed density of soil seed bank at the low altitude areas was generally higher than that at the high altitude areas. The seed density of soil seed bank at the low part was higher than that of the middle and upper parts within the same slope.( 3) The similarity of species composition between soil seed bank and standing plant community in the region was relatively low. The similarity coefficient decreased with the increasing of elevation. All of these results suggested that the elevation was an important factor affecting the species composition and density of soil seed bank. The ecological restoration of the slope in this area needs to select appropriate species to artificially construct the seed banks according to elevation gradient.更多还原