共和盆地两种柳树的根系分布差异

Root distribution difference of two Salix shrubs in Gonghe Basin

在青藏高原共和盆地,乌柳和沙柳是丘间地造林的主要树种。文中通过剖面法比较了28年生两种柳树的不同径级的根系分布。结果表明:两种柳树是深根系植物,深度分别是1.2和1.1m。乌柳的根系总干重主要分布在0-80cm。乌柳的不同径级根系的干重和长度分布范围不同。它的粗根、中根和细根的干重分别主要分布在0-80、0-70和0-40cm,而长度分别主要分布在0-80、0-70和0-90cm。沙柳的根系总干重主要分布在0-70cm。沙柳的不同径级根系的干重和长度分布范围相同。它的粗根、中根和细根分别主要分布在0-50、0-70和0-70cm。乌柳的主根和细根向更深的土壤中生长,可以吸收更稳定的深层土壤水。沙柳的主根和细根相对较浅,主要吸收降雨补充的浅层土壤水。乌柳和沙柳根系分布的差异体现了它们对共和盆地半干旱气候的不同适应策略。

Salix cheilophila and Salix psammophila are main shrubs used in the re - vegetation on interdune in Gonghe Basin of Qinghai - Tibetan Plateau. Distribution characteristics of root of 28 - years old of two Salix shrubs were studied by profile method. The results showed that S. cheilophila and S. psammophila are deep - rooted shrubs, the roots grow as deep as 1.2 and 1.1 m, respectively. The total dry mass of S. cheilophila root mainly distributes in 0 - 80cm. The distribution range of S. cheilophila root is different for different level of root diameter. The dry mass of its tap root, medium roots and fine roost mainly distribute in 0 - 80, 0 - 70 and 0 - 40cm, respectively. However, their length mainly distribute in 0 - 80, 0 - 70 and 0 - 90cm, respectively. The total dry mass of S. psammophila root mainly distributes in 0 -70cm. The distribution range of S. psammophila root is same for different diameters. Its tap root, medium root and fine root mainly distribute in 0 -50, 0 -70 and 0 - 70cm, respectively. The tap and fine roots of S. cheilophila are deeper and absorb more stable deep soil water. The tap and fine roots of S. psammophila are relatively shallower and mainly absorb shallow soil water recharged by rain. The difference in root distribution of S. cheilophila and S. psammophila reflects their different adaptation strategy to semiarid climate in Gonghe Basin.