内蒙古锡林河流域不同生境中羊草的克隆构型和分株种群特征

CLONAL ARCHITECTURE AND RAMET POPULATION CHARACTERISTICS OF LEYMUS CHINENSIS FROM DIFFERENT HABITATS IN THE XILIN RIVER WATERSHED

克隆植物的形态可塑性在基株和种群水平上分别表现为克隆构型和分株种群特征的变化。研究对象为内蒙古锡林河流域草地、林地、沙地 3种生境下的羊草 (Leymuschinensis)种群 ,通过对羊草根茎节间长度、间隔子长度、分枝强度、分枝角度、株高和分株密度等指标的测定和分析 ,对这 3种不同生境中羊草的克隆构型及分株种群特征进行了研究。结果表明羊草克隆构型相关特征 ,如 ,根茎节间长度 ,根茎节间长度频次分布格局、间隔子长度、间隔子长度频次分布格局 ,在不同生境差异较大。同时 ,羊草的分枝角度在不同生境间差异显著。而每间隔子所包含的节数和分枝强度在 3种生境间却无显著变化。总的来说 ,草地和沙地羊草的克隆构型趋于游击型 ,而林地羊草趋于密集型。表现分株种群特征的分株高度和密度在不同生境也具有较大差异。最后结合克隆植物对资源的利用对策 ,对不同生境中的不同克隆构型 ,分株种群特征进行了讨论。

We compared internode length, nodes per spacer, spacer length, branching intensity, branching angle, frequency distribution of internode length, frequency distribution of spacer length, ramet population density and ramet height of Leymus chinensis among three different habitats including grassland, woodland and sandland along the Xilin River watershed. The result reveal that characters of L. chinensis such as spacer length, internode length and branching angle, frequency distribution of internode length and frequency distribution of spacer length differed among habitats, while nodes per spacer and branching intensity did not. Population characters like ramet population density and ramet height were also different among the three habitats. Clonal architecture of the species tended to be guerilla in grassland and sandland, but phalanx in woodland habitat. These results are discussed in the context of resource acquisition strategy by clonal plants.