不同密度四翅滨藜人工种群的分枝格局可塑性分析

An Analysis on Branching Pattern Plasticity of Atyiplex canescen Populations in Different Densities

利用植物种群的构件结构理论,对不同栽培密度下四翅滨藜分枝格局可塑性进行了研究。结果表明,分支格局主要受空间资源和光照资源的影响,主要表现在:(1)在高、冠幅以及分枝数方面生长均存在显著差异,高与密度呈正相关,类型Ⅰ植株高大于类型Ⅱ和类型Ⅲ;冠幅以及各级分枝数与密度呈负相关,冠幅类型Ⅲ大于类型Ⅰ,各级分枝数类型Ⅲ和类型Ⅱ大于类型Ⅰ,且差异显著;(2)在1级/2级分枝率、2级/主侧枝分枝率、2级枝平均分枝角度、2级枝平均长度在3种类型中不存在差异,而在主侧枝节间距、主侧枝平均枝长度、1级枝平均分枝角度方面类型Ⅲ与类型Ⅱ和类型Ⅰ之间存在显著差异,而在主侧枝平均分枝角度、1级枝平均枝长度方面类型Ⅲ和类型Ⅱ与类型Ⅰ之间存在显著差异,而且密度越小,其差异越显著;(3)不同方位分枝格局差异主要表现在主侧枝分枝角度、1和2级枝平均长度、分枝角度,主侧枝分枝角度南大于东、西,1级枝分枝角度北大于东、西、南,2级枝分枝角度西、北大于东、南,1级枝平均长度东、南大于西、北,2级枝平均长度南、北大于东、西,而主侧枝节间距,平均枝长度差异不明显。由以上分析表明,四翅滨藜具有很强的空间结构可塑性,人工种群栽培密度不应小于2 m×2 m。

Based on the theory of module construction, branching pattern plasticity of Atyiplea： canescen in different cultivated densities were studied. The results showed that branching patterns were influenced mainly by the space and illumination. （1）There were remarkable differences in height,crown breadth and number of branching; height and density were positively related; The plants of type Ⅰ were higher than those of type Ⅱ and type Ⅲ Crown breadth, branching number and density were negativly relatied; The crown size of type Ⅱ was bigger than that of type Ⅰ, and the branching numbers of type Ⅲ and Ⅱ were more than those of type Ⅰ in every grade, the difference were significant. （2）There were no differences in the bifurcations rations of ANB1/ANB2 and ANB2/ANMB, the average angle, and length of ANB2, but there were significant differences in the average angle, length and the node distance of ANMB and the average angle, length of ANB1, the length and node distance of ANMB, and the average angle of ANB1 of type Ⅱ were bigger than those of type Ⅰ and type Ⅱ , the average angle of ANMB and the average length of ANB1 of type Ⅱ and type Ⅰ were bigger than those of type Ⅰ , the bigger the density, the more significant the differences. （3） The difference of branching pattern in different directions were exhibited in the average angle of ANMB, the average angle and the average length of ANB1 and ANB2, but not in the node dis-tance and the average length of ANMB, The average angle of ANMB in the direction of south was bigger than those east and north, the average angle of ANB1 in the direction of north was bigger than those in south, East and West, the average angles of ANB2 in the directions of west and north were bigger than those in east and south, the average lengths of ANB1 in the direction of east and south were bigger than those in west and north. As a result, the branching pattern plasticity of A. canescen was stronger, the planting density was no less than 2 m × 2 m.