收稿日期: 2014-06-16
修回日期: 2014-08-12
网络出版日期: 2015-09-20
基金资助
国家杰出青-科学基金项目(41125002)
Effects of Seed Density on the Germination and Seedling Growth of Haloxylon ammodendron
Received date: 2014-06-16
Revised date: 2014-08-12
Online published: 2015-09-20
研究了梭梭(Haloxylon ammodendron)种子密度对萌发和幼苗生长、存活的影响及其对梭梭种群更新的作用。在自然条件下设置80、160、320、480、640、960粒·m-2 等6个种子密度处理,每个处理5次重复,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:种子萌发率随密度的增加呈增长趋势,在密度为80粒·m-2时,萌发率为28%,当密度达到960粒·m-2时, 萌发率为54%;幼苗存活率随种子密度增加呈现先增加后减小的趋势,160粒·m-2种子密度下出土幼苗存活率最高为25%,320粒·m-2种子密度下出土幼苗存活率最高为22%,当密度增加到960粒·m-2,萌发出土的幼苗成活率为11%;综合考虑种子萌发率和幼苗存活率,在1 cm沙埋深度下320 粒·m-2为最佳密度。幼苗生长高度会受到幼苗数量的影响,单位面积上一定范围内幼苗数量增加可以使幼苗生长高度增加,但当幼苗数量超过一定范围,幼苗生长减慢。单纯从幼苗数量来看,种子密度越大,幼苗更新数量越多。
关键词: 种子密度; 梭梭(Haloxylon ammodendron); 更新; 生长高度
王国华 , 赵文智 . 梭梭(Haloxylon ammodendron)种子密度对萌发及幼苗生长的影响[J]. 中国沙漠, 2015 , 35(5) : 1248 -1253 . DOI: 10.7522/j.issn.1000-694X.2014.00127
The field experiment was conducted to understand the effects of different density of seed on the seedling emergence and growth of Haloxylon ammodendron under nature conditions. There were six treatments in the seed burial experiment,i.e.,80, 160, 320, 480, 640, 960 seed·m-2, and every treatment had five repeats. We observed the seed germination and seedling growth for the entire growing season. Our results demonstrate that the seedling emergence increased with the seed density. When seed density of H. ammodendron at 1 cm reached to 960 seed·m-2 and the seedling emergence rate was 54%. When the seed density reached to 160 seed·m-2, the seedling survival rate reached to 25%. And then with the increase of seed density the survival rate began to decrease. When the seed density reached to 960 seed·m-2, the survival rate decreased to 11%. In sum, the seed density of 320 seed·m-2 was the optimal seed density. In our study we also found that the seedling height increased with the seed density of 80-480 seed·m-2, then decreased from 640-960 seed·m-2. The seedling height of 480 seed·m-2treatment can reach to 25.9 cm after 1 year, but the seedling height of 960 seed·m-2 treatment was 14.5 cm. From the aspect of seedling number, with the increase of seed density, the seedling number increased.
Key words: seed density; Haloxylon ammodendron; regeneration; seedling height
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