通过对林窗中央、林窗边缘和林下3种生境紫楠幼苗生长、叶性状和生物量分配的研究，来探明不同生境下紫楠表型可塑性的变化。结果表明：林窗中央紫楠幼苗保存率最低，林窗边缘和林下生境保存率较高。苗高和地径在3种生境下没有显著差异，枝干、叶和单株总生物量均以林窗边缘最大。紫楠叶长（LL）、叶面积（AL）和叶周长（ PL ）在林窗中央和林窗边缘显著低于林下生境，但林窗中央和林窗边缘这3个参数差异不显著。叶片碳、氮、钾质量分数以及比叶面积（SLA）、w（C）／w（N）和w（N）w／（K）在3种生境下没有显著差异。紫楠幼苗在林窗中央和林窗边缘生境中将相对多的生物量分配给地上部分生长，其中，林窗边缘分配给地上部分生物量的比例（86％）大于林窗中央（80％）；而林下生境将生物量相对多地分配给叶片和根系。总体上紫楠幼苗叶性状的表型可塑性较低，生物量分配的表型可塑性指数较高，说明其主要通过生物量分配比例的改变来适应不同生境的变化。%For exploring the changes of phenotypic plasticity of Phoebe shearer seedling in different habitats , we studied the growth, leaf traits and biomass assignment of P.shearer seedlings in gap center ( GC) , gap edge ( GE) and under canopy ( UC) habitats .The preserving rate of seedlings in the GC habitat was lowest , and higher preserving rate occurred in the GE and UC habitats .For height and diameter at ground of seedling there were no significant differences among the three habitats, and stems biomass, leaves biomass and total plant biomass were maximum in the GE habitat .Leaf length (LL), leaf area (LA) and leaf perimeter (LP) were significantly lower in the GC and GE habitats than those in the UC habitat . There was no significant difference for the three variables between GC and GE habitats .There was no significant difference among leaf carbon( C), nitrogen (N), potassium (K) contents, specific leaf area (SLA), w(C)/w(N) and w(N)/w ( K) under the three habitats .Relatively more biomass allocated to aboveground growth in the GC and GE habitats , the proportion of allocating to aboveground biomass was greater in the GE habitat ( 86%) than that in the GC habitat ( 80%) . For UC habitat, there was relatively more biomass allocating to leaves and roots .Overall, the phenotypic plasticity of leaf traits of P.shearer seedlings was low , the phenotypic plasticity of biomass allocation was higher , and P.shae rer seedlings could regulate the proportion of biomass allocation to adapt to different habitats .
展开▼
