青藏高原东缘小花风毛菊花期繁殖分配的海拔差异

Reproductive allocation changes from Saussurea parviflora in eastern edge of Qinghai-Tibet Plateau at various altitudes during flowering

摘要:

通过采样调查法和烘干称重法，对分布在青藏高原东缘不同海拔高度下的小花风毛菊（Saussurea parviflora）的花期繁殖分配进行研究，结果表明：1）花期植株地上生物量、株高、管状小花数目、繁殖器官及营养器官生物量均随海拔升高呈线性递减趋势，管状小花生物量随海拔升高呈线性递增趋势；2）花期繁殖分配随海拔升高呈线性递增趋势；3）花期繁殖分配随个体大小（地上生物量和株高）的增大呈线性递减趋势；4）花期管状小花生物量与管状小花数目之间存在权衡现象。由此推论：1）海拔作为外界因子对小花风毛菊花期各生物量及繁殖分配有显著的影响，但海拔不是影响小花风毛菊繁殖分配的唯一生态因子，地上生物量和株高对其繁殖分配也存在潜在调控作用；2）在不同海拔梯度上，小花风毛菊有效的整合了有限的资源，其适应性特征之一就是通过减小个体大小来削弱营养生长以达到促进生殖生长的目的。

Abstract:

To study the effect of elevation on the reproductive allocation of Saussurea parviflora during the flowering，sampling survey method and weighting after dried method are chosen so as to study Saussurea parviflora 's morphological features at various altitudes.It show that, firstly,during flowering,above-ground biomass in plant itself and its organs related to reproduction and vegetation has an obvious trend of decreasing as altitude goes up.Besides,its number and stem length also slope down little by little.On the contrary,tubuliflorous biomass and reproductive allocation take on a relative trend of increasing and prosperity.Secondly,a shift phenomenon in balance from tubuliflorous biomass and its number would probably be formed.Thirdly,in flowering,biomass in many aspects and reproductive allocation are potentially controlled by the environmental factor,altitude .Finally ,for the external resource is limited ,in order to relatively promote its productive growth ,this kind of smart plant weaken the vegetation growth by quietly inhibiting its individual size .In this way, Saussurea parviflora’s breeding success rate is greatly and amazingly lifted .