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通过紫椴 (TiliaamurensisRupr.)幼苗在不同植距下纯栽和与落叶松 (Larixgmelini)的混栽沙培试验 ,初次应用通径分析 ,研究紫椴幼苗生物量分配和资源利用机制 ,分析种内和种间竞争及其模式。研究发现总体上植距增大有利于紫椴根、茎、叶各器官的生长。通过通径分析说明 ,紫椴地下根系对总生长的贡献为 0 .2 36 1～ 0 .2 86 9,地上茎、叶对总生长的贡献为 0 .732 5～ 0 .775 8,地上部分的贡献是地下根系的 2 .95倍。表明紫椴幼苗对光具有较强的需求和竞争能力。紫椴和落叶松之间存在悬殊较大的生物量差距 ,落叶松的根、茎、叶生物量约是相应混栽紫椴的 2、5、4倍。通过比较纯栽和混栽试验中的直接通径系数 ,与落叶松混栽后 ,紫椴对地下水分养分的竞争下降36 .84 % ,对地上光照空间的竞争增大 11.6 3%。随植距减小落叶松对紫椴的影响增大 ,紫椴根系生长受落叶松种间竞争影响不显著 ;地上茎、叶生长只在一定植距范围内受落叶松影响。紫椴与落叶松种间竞争是不同资源利用等级的两树种间的相互作用 ,以对称性地下竞争与落叶松“平等”地占有地下水分养分资源 ,从而受落叶松地下竞争较小 ;在一定空间范围内落叶松以非对称性竞争优先占有地上光照资源影响紫椴生长。
Through Triticeae (Tilia amurensis Rupr.) Seedlings planted at different planting distances and Larixgmelini mixed sand culture experiments, the path analysis was used for the first time to study the biomass allocation and resource utilization mechanism of Tilia amurensis seedlings, And interspecies competition and patterns. The study found that the overall planting distance is conducive to the growth of Tilia amurensis roots, stems and leaves of various organs. Path analysis showed that the contribution of Tilia amurensis roots to total growth was 0.236 1-0.286 9 and the contribution of aboveground stems and leaves to total growth was 0.732 5-0.775 8. The contribution is 2.95 times that of underground roots. Tilia amurensis seedlings show that the light has a strong demand and competitiveness. Tilia and Larix gap between the large differences in biomass, larch roots, stems, leaf biomass is about 2,5,4 times the corresponding mixed Tilia amurensis. By comparing the direct path coefficient in pure and mixed experiments, the competition of groundwater nutrient by Tilia amurensis decreased by 36.84% and that of aerial litter increased by 11.63% after mixed with Larch. Larix gmelini increased with the decrease of the distance between the two plants. The root growth of Tilia amurensis was not significantly affected by the competition among species of Larch. The growth of aboveground stems and leaves was affected only by larches within a certain range. Interspecific competition between Tilia amurensis and Larix gmelinii is an interaction between two tree species with different utilization levels of resources. Underground competition with Larch is shared underground aquaculture resources by “symmetry” underground competition with Larch; Larch in the spatial range preferentially competes with asymmetric competition to occupy aboveground light resources and affect the growth of Tilia.