差巴嘎蒿和小叶锦鸡儿根系分布及生长动态的初步研究

Morphology,Distribution and Dynamics of Root Systems of Artemisia halodendron and Caragana microphylla.

用壕沟法和Ｍｉｎｉｒｈｉｚｏｔｒｏｎ法对差巴嘎蒿（Ａｒｔｅｍｉｓｉａｈａｌｏｄｅｎｄｒｏｎ）和小叶锦鸡儿（Ｃａｒａｇａｎａｍｉｃｒｏｐｈｙｌｌａ）根系形态、分布和生长动态的研究表明，差巴嘎蒿根系大量分布于５～３０厘米的土层中，小叶锦鸡儿根系多分布于２０～８０厘米的土层中．有根瘤，一般土壤发育越好根瘤越多。围栏封育四年以后差巴嘎蒿的生长开始减弱．表现为吸收性根（直径小于１毫米）的分生数量显著少于放牧区。生物季两种植物根系数量的增减受降雨频度和降雨量的影响，与地上部分的物候期关系不明显。新根开始生长的日期晚于地上部分萌动的日期，约５０％的吸收性根在冬季死亡。

Root systems of Arternisia halodendron and Caragana microphylla were studied during 1988～1990 in a field experment on sand dunes with trench and minirhizotron meth- ods. The observations show (1)the root systems of A. halodendron and C. microphyl- la disteributed in 5～30cm and 20～80cm depth soil layrs,respectively;the root system of C. microphylla has nodules for fixing nitrogen,the more fertile the soil was ,the more nodules the C. microphylla roots had;(2)the roots of A. halodendron grow weakly after the vegetation was protected form grazing and cutitting. There are more ab- sorbent roots(fine root D<1mm)of the plants which grow at grazed area than at pro- tected area;(3)the root mass of the two species was affected by rainfall.The root growth started in early may,later than above ground parts of plant sprouttings.There is not distinct relationship between root growth dynamics and the phenology of the both species. About 50% of fine roots dide during inter.