不同供水条件下梭梭幼苗生长动态的研究

Seedling Growth Dynamic of Haloxylon ammodendron under Different Water Supply

在自然条件下,以梭梭幼苗为研究对象,设计单次供水10、20、40、60mm和80mm 5个水分梯度,模拟不同融雪量对幼苗在生长季节内影响变化的情况。结果表明,供水量显著影响了梭梭的幼苗高、根长、苗干重、根干重、基径。在整个生长季的一些阶段,对苗高、根长、苗干重、根干重、基径生长率影响显著,对其根冠比也有显著的影响。在实验供水范围内,供水越多,越有利于梭梭幼苗存活与生长。梭梭幼苗垂直根长大约是株高的3～5倍,梭梭垂直根长增加的速率明显大于高度增长的速率(一般为2～6倍,最大甚至超过10倍),因此,在干旱期来临之前,幼苗根系的快速生长对其成活起着决定性作用。

In the natural condition,the responses of seedling growth of Haloxylon ammodendron to melting snow change are investigated by artificially controlling water supply at five levels of 10 mm,20 mm,40 mm,60 mm and 80 mm.Results show that the quota of water supply significantly affects seedling height,root length,seedling dry weight,root dry weight and stem base diameter.At some stages of the growing season,the responses of increments of seedling height,root length,seedling dry weight,and root dry weight and stem base diameter to water supply are significant,and the response of root/shoot ratio is also significant.It is more benefit to survival and growth of H.ammodendron with water supply of 10～80 mm.Throughout the growing season,the length of vertical root of H.ammodendron is 3～5 times the height of shoot,and the growth speed of the vertical root is 2～6 times the growth speed of shoot.The rapid growth of root is decisive to survival and growth of seedlings of H.ammodendron.