天然固定沙地不同微生境下土壤种子库差异

研究了腾格里沙漠东南缘天然固定沙地不同微生境下土壤种子库的种类组成和种子密度。结果表明:(1)灌丛下土壤种子库的物种丰富度大于灌丛边缘和灌丛间裸地。(2)不同微生境中土壤种子密度因物种而异。就距灌丛中心的距离来说,雾冰藜、刺蓬、地锦、虎尾草、虱子草和冷蒿灌丛下土壤中种子多于裸地,无芒隐子草和狗尾草种子裸地多于灌丛下,小画眉草在距灌丛各距离间土壤种子密度差异不显著。(3)就灌丛的不同方向来说,雾冰藜和刺蓬土壤中种子在东南方向最多,地锦和无芒隐子草土壤中种子密度在西南和西北均大于东南,狗尾草的土壤种子密度东北大于西北,虱子草的土壤种子密度在西南方向最大,冷蒿的土壤种子密度在西南方向最小,小画眉草和虎尾草在各方向间种子密度差异不显著。(4)不同微生境中物种的结籽量对土壤种子分布格局的影响力十分有限。种子离开母株后所经历的传播、消耗等过程在很大程度上打乱了植物结籽量的空间样式。

A comparative study of soil seed banks over different microhabitats in naturally stabilized sandy land

Assessing the differences in seed composition of distinct microhabitats can clarify the relationship between soil seed banks' patterns and processes.Knowledge on different seed types' specific location may explain the spatial pattern of plant recruitment at the microhabitat scale.In this regard,the soil seed bank composition and its density at the southeast edge of the Tengger Desert in Northern China were studied over 12 microhabitats around the Caragana korshinskii shrub.Specifically,we selected 40 indivi...