不同养分条件下和不同生境类型中根茎草本黄帚橐吾的克隆生长

CLONAL GROWTH OF LIGULARIA VIRGAUREA:MORPHOLOGICAL RESPONSES TO NUTRITIONAL VARIATION

对多年生植物黄帚橐吾 (L igularia virgaurea)在不同氮肥梯度和不同生境类型中的克隆生长行为进行研究。结果表明 :l)资源水平与群落性质影响着间隔子 (Spacer)长度的变化 ,氮肥处理使之明显变短 ;自然群落中的间隔子长度远远长于人工群落 ,说明黄帚橐吾间隔子具有很强的形态可塑性 ,能对资源水平和生境优劣作出反应。2 )分枝强度 (Branching intensity)具有随资源水平的增高而上升的趋势 ,表明无性系分株 (Ramet)的形成和生长受环境资源状况和源株 (Genet)生长状况的影响 ;3)黄帚橐吾的分枝角度为 0°或 180°,资源水平与环境差异对其影响不大 ,可塑性低 ;4)环境资源贫乏或植株比较拥挤时 ,黄帚橐吾个体根系资源分配比例加大 ,说明黄帚橐吾的资源分配 (Resource allocation)模式更多地受环境资源条件和群落性质的影响。

Clonal growth of the perennial plant Ligularia virgaurea was studied in respect to varying nitrogen availability and habitat The results showed: 1) Spacer length was affected by resource levels and community characteristics. Increased nitrogen led to shortened spacer length, while spacer length was also shortened in the artificial community relative to the natural community (alpine meadow). This shows strong morphological plasticity in spacer of L. virgaurea in response to varying resource levels and habitat quality; 2) Branching intensity increased with resource levels, but there was no obvious difference between the natural and artificial communities. The formation and growth of ramets is affected by both the environmental resource condition and the growth condition of genets. 3) Branching angle of L. virgaurea was not affected by resource levels and habitat: its morphological plasticity was very low. 4) Under conditions of resource depletion or community crowding resource allocation to roots was high, further showing that resource allocation patterns are also affected by both environmental resource conditions and community structure.