Abstract: In order to explore the influence of habitat on modular biomass allocation of Crotalaria spectabilis and the trade-offs among organs,two habitats (understory and bare land) were selected,and the biomass allocation and allometric relationship among plant organs,and their differences and trade-offs between the two habitats were analyzed through filed investigation and lab analysis. The results showed that the dry weights of all organs and the whole plant,and the reproductive allocation in the bare land habitat were significantly higher than that in the understory habitat,respectively;while the root to shoot ratio and stem to total biomass ratio were markedly lower than that in the understory habitat. The allometric relationships were found between most organs in the understory habitat,while most organs presented isometric relationship in the bare land habitat;however,in both two habitats,the reproductive allocation ratios were both significantly higher than other organs. The reproductive allocation ratios increased significantly with the increase of plant size,while the stem and leaf biomass allocation ratios decreased significantly,indicating an opposite trend of size dependence. Consequently,when facing varied environments,C. spectabilis exhibits obvious adjustment and trade-off of resource allocation among organs.

Key words: Habitat, Resource allocation, Allometry, Size-dependent, Reproductive allocation

摘要： 为探讨生境对大托叶猪屎豆（Crotalaria spectabilis）构件生物量分配及其权衡关系的影响，本研究选择林下和裸地2种生境，通过野外调查取样和室内分析，研究了大托叶猪屎豆构件生物量分配特征、异速生长关系及其在生境间的差异性和权衡特征。结果表明，裸地生境大托叶猪屎豆各器官干重、全株干重及繁殖分配比例均显著高于林下，但其根冠比和茎生物量比则显著低于林下。林下生境构件生物量之间多为异速生长关系，而裸地生境多为等速生长关系，但2种生境下繁殖分配速率均显著高于其他构件。繁殖分配比例随个体增大显著增加，而茎与叶生物量分配则显著降低，呈现相反的个体大小依赖性。可见，大托叶猪屎豆在面对变化环境时不同器官间具有显著的资源分配调整与权衡。

关键词: 生境, 资源分配, 异速生长, 个体大小依赖, 繁殖分配