桂林喀斯特生境红背山麻杆克隆繁殖特征

Characteristics of Clonal Reproduction of Alchornea trewioides in Karst Region of Guilin,China

通过研究桂林喀斯特生境砍伐干扰克隆繁殖(FICP,felling interferes clonal production)和无干扰克隆繁殖(NICP,non-interfering clonal production)2种类型的红背山麻杆Alchornea trewioides繁殖群落,利用多元统计方法分析红背山麻杆前后端水平侧根直径、分株数和地径,探讨红背山麻杆对适应喀斯特生境所表现出来的克隆繁殖特征,旨在为喀斯特石山地区的植被恢复建设提供理论依据。结果表明:(1)红背山麻杆根分枝强度较弱,方向性较强,分株不密集,表现为“游击型”克隆植物。(2)砍伐干扰对红背山麻杆的克隆繁殖具有促进作用。(3)砍伐干扰克隆繁殖的克隆分株存活率比无干扰克隆繁殖的低,风险分摊现象比无干扰明显。(4)红背山麻杆前后端水平侧根具有不对称性:在克隆分株地径小于0.2 cm时,后端水平侧根小于前端水平侧根越过临界点0.2 cm后,后端水平侧根大于前端水平侧根。

In this research,two community types of felling interferes clonal production(FICP)and non-interfering clonal production(NICP)in Alchornea trewioides were studied in the karst habitat of Guilin.The multivariate statistical method was used to analyze ground diameter,numbers of ramets and basal diameter of the front part and the rear part,to discuss the clonal characteristics of A.trewioides for adaption to karst habitat,in order to provide guidance for vegetation restoration in the karst areas.The results showed that(1)the roots of A.trewioide were weak in branching,and strong directions.The ramets were not dense,showing as"guerrilla"clone plants.(2)FICP promoted clonal reproduction of A.trewioide.(3)The ramets’survival rate of FICP was lower than that of NICP,indicating more obvious risk allocation in FICP than NICP.(4)There was an asymmetry between lateral roots of the front and rear parts:The lateral root of the rear part was smaller than the front one,when the ground diameter was less than 0.2 cm.However,when the ground diameter was more than 0.2 cm,the lateral root of the rear part was larger than the front one.