毛乌素沙地臭柏群落景观动态

Dynamics of Sabina vulgaris phytocoenosis landscape in Maowusu Sandland

运用景观生态学的基本原理,在毛乌素沙地天然臭柏Sabinavulgaris群落分布区内随机选择24个臭柏灌丛,测定臭柏灌丛边缘匍匐枝在东南西北4个方向上的年生长量,并且在各个臭柏灌丛的边缘和中心设置小样方,测定小枝密度、枝下枯枝长及气体交换特征,研究毛乌素沙地臭柏群落景观的结构、功能及动态。结果表明:①毛乌素沙地臭柏群落以10.2cm.a-1的半径生长量向外扩大,群落扩大的速率在年度间差异较大,在各个方向上差异较小。②臭柏群落的扩大速率随地下水的下降而减小。③群落景观的边缘效应明显,群落边缘比中心有较大的物质流和能量流。

Annual growth of shoots of 24 randomly selected shrubs of Sabina vulgaris in 4 directions was measured with the basic principles of landscape ecology. Plots were set up in the center and on the edge of the shrubs; the shoot density, deed shoot length and gas exchanges characteristics of the plots were measured. And structures, functions and dynamics of S. vulgaris phytocoenosis landscape in Maowusu Sandland were studied. The results were as follows: (1)S. vulgaris phytocoenosis in Maowusu Sandland were expanding at the annual radial growth of 10.2 cm. Expanding rates of phytocoenosis were quite different in the different years. There was small difference in the directions of expansion. (2) Expanding rate of S. vulgaris phytocoenosis was reduced when water ground level fell. (3) Edges effect of phytocoenosis was distinct and the mass flow and energy flux on the edge were bigger than those in center.[Ch,3 fig.3 tab.15 ref.]