埋藏深度对梭梭(Haloxylon ammodendron)种子萌发及幼苗生长的影响

Effects of Sand-burying on Seed Germination and Seedling Growth of Haloxylon ammodendron

研究了不同沙埋深度对于梭梭(Haloxylon ammodendron)种子萌发和幼苗生长、存活的影响,判断梭梭种子萌发后,幼苗能否成活以实现梭梭种群的更新。在自然条件下设置0、1、2、3、4、5cm深度沙埋处理,每个处理5个重复,对梭梭种子萌发和幼苗生长进行了全生长季观测。结果表明:梭梭种子为喜光种子,种子萌发率随着沙埋深度的增加呈减小趋势,萌发最佳沙埋深度为1cm,萌发率为39.2%,4cm已是萌发的最大沙埋深度;幼苗存活率随着沙埋深度的增加而增加,4cm沙埋深度出土幼苗存活率为100%,而0cm萌发出土的幼苗成活率为0;综合考虑种子萌发率和幼苗存活率,2cm为最佳沙埋深度,这个沙埋深度出土的幼苗对于梭梭种群更新贡献最大。幼苗生长高度受沙埋深度的影响显著,在1~4cm沙埋深度范围内,浅层沙埋出苗快但生长慢,而深层沙埋出苗慢而生长快,幼苗最大生长高度在4cm沙埋,第一年生长季最大生长高度为21.5cm,幼苗最小生长高度在0cm,第一年生长季最大生长高度仅为2.76cm。

This paper studied the effects of sand-burying on the seed germination and seedling emergence and growth of Haloxylon ammodendronin a typical arid desert region under nature conditions.Six treatments of sand-burying of depths 0,1,2,3,4 cm and 5 cm were designed and each treatment included five replicates.Results demonstrated that the seedling emergence decreased with increasing sand-burying depth.The optimal sand-burying depth for seedling emergence of H.ammodendron was 1 cm and the seedling emergence rate at this depth was 39.2%.The depth of 4 cm was the maximum depth for H.ammodendronto emerge.However,the seedling growth rate and survival rate of H.ammodendron increased with increasing sand-burying depth.The seedling survival rate of H.ammodendron at 4 cm burial depth was 100%and the survival rate at0 cm was 0.Considering both seed germination rate and seedling survival rate,the optimal burial depth was2 cm and the seedlings at 2 cm burial depth were the main source for population regeneration.Seedling height was significantly affected by the sand burial depth.At the same period,the maximum seedling height of H.ammodendron was at 4 cm sand burial depth and the minimum was at 0cm.In the first year,the seedling height of H.ammodendron unearthed from4 cm was 21.5 cm and the height of seedling unearthed from surface was only 2.76 cm.