不同萌枝类型云南红豆杉幼树生物量分配及其异速生长

Biomass Allocation and Allometry of Taxus yunnanensis Saplings from Different Sprout Types

研究不同萌枝类型云南红豆杉器官生物量分配格局及其异速生长现象,了解幼树的个体发育规律及适应策略。将福建明溪4年生萌枝云南红豆杉,按萌枝相对高分成3个萌枝高度类型,调查分析不同萌枝类型云南红豆杉幼树生物量及其分配差异,采用标准化主轴估计法分析其异速生长关系,揭示不同类型幼树的发育规律与适应策略。结果表明,云南红豆杉幼树生物量及其分配格局在类型间具有显著差异,但各器官生物量分配均表现为枝叶>茎、根,地上部分>地下部分;低位类型的各器官生物量、总生物量以及茎、枝叶的生物量分配比最大。幼树器官生物量间以及器官生物量与个体大小间的异速生长关系在不同类型不尽相同。不同类型根生物量与茎生物量间,根生物量、茎生物量与个体大小间有着相同异速生长指数。不同类型幼树同时存在等速生长、异速生长现象。不同萌枝类型间幼树生物量及其分配格局差异显著,存在着丰富遗传变异。不同类型间器官生物量分配的差异是各器官、各器官与枝大小之间异速生长和枝大小差异共同作用的结果。异速生长关系在不同萌枝类型间并不唯一,反映着不同类型幼树生长与适应策略。建议采用低位类型发展云南红豆杉原料林。

The biomass allocation pattern and allometric relationships of Taxus yunnanensis saplings from different sprout types were studied to understand the ontogenyetic law and adaptive strategy of the saplings.Four-year-old sprout saplings of T.yunnanensis growing in Minxi of Fujian Province were divided into 3 types based on the sprout relative height.Differences in saplings biomass and biomass allocation among different sprout types were investigated and analyzed.The allometric relationship was analyzed by standardized major axis analysis,and the ontogenetic law and adaptive strategy of T.yunnanensis saplings with different sprout types were revealed.The results showed that there existed significant differences in biomass and its allocation among different types,the biomass allocation in each organ was in the order of branch and leaf>stem and root,and the aboveground part>underground part.The highest biomass of each organ,total biomass and the highest biomass allocation ratio of stem appeared in the low type.The allometric growths relationship within organ biomass and organ biomass to individual size of the saplings among different sprout types were quite discrepant.The same allometric scaling exponent index was found between root biomass&stem biomass,root biomass,stem biomass&individual size of the samplings with different types.The saplings of different types had both isometric and allometric relationships.It is concluded that there are significant differences in biomass and its allocation among different sprout types of T.yunnanensis saplings,indicating the existence of abundant genetic variations.Differences of organ biomass allocation among different sprout types are the results of the joint effects of allometric growth among organs,organs and branches,and individual size difference.There is no consistency allometric growth relationship among different sprout types,it represents the growth and adaptation strategies of the saplings with different sprout types.It is suggested that low type should be adopted to develop the T.yunnanensis raw material forest.