领春木幼苗形态及生物量分配对光环境的响应

The Response of Morphological Plasticity and Biomass Allocation of Euptelea pleiospermum Seedlings to Different Light Regimes

研究了旷地、林窗和林下3种不同生境中,领春木(Euptelea pleiospermum Hook.f.et Thoms.)幼苗的生长、形态特性、生物量及其分配对不同光环境的响应。结果表明,光资源不足的情况下,领春木幼苗生长受到抑制。生长于林窗的领春木幼苗有更多纵向生长趋势以获取更多的光资源,并通过增加叶片数和总叶面积来提高对光能的利用。领春木幼苗通过提高根生物量比和降低比叶面积,减小强光对幼苗的损伤。光强较弱时,则是将更多的生物量投资于地上部分,主要用于高生长和叶生长,以增加对光辐射的吸收。领春木生长环境光照偏弱,但其幼苗适于生长于光照偏强的环境,这可能是领春木幼苗在其种群更新中受到光环境抑制的原因,加上对成年植株及其生长环境人为的破坏,可能是导致领春木数量减少的原因之一。

This study examined the responses of the growth,morphological characteristics,biomass and the biomass allocation of Euptelea pleiospermum seedlings to three natural light regimes （open,gap and understory）.The main results were as follows：the growth of Euptelea pleiospermum seedlings was inhibited when the light was insufficient;Euptelea pleiospermum seedlings grew in the gap had more vertical growth trend for more light resources and they increased the number of leaves and the area of them to enhance the use of light;Euptelea pleiospermum seedlings reduced the damage of glare on the seedling by increasing the root mass ratio and lowering specific leaf area;when the light was weak,more biomass was invested in shoot,mainly for high growth and leaf growth,to increase the absorption of light.The growing environment of Euptelea pleiospermum was weak in light,but the seedlings needed more light,which would cause Euptelea pleiospermum seedlings suppressed by the light in population regeneration,coupled with human damage on the grown plants and their environment,this might be one reason of the decrease in the number of Euptelea pleiospermum.