Role of seed size and relative abundance in conspecific negative distance-dependent seedling mortality for eight tree species in a temperate forest
Role of seed size and relative abundance in conspecific negative distance-dependent seedling mortality for eight tree species in a temperate forest
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DOI：
10.1016/j.foreco.2019.117537
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发表时间：
2019-12
影响因子：
3.7
通讯作者：
K. Seiwa;K. Masaka;M. Konno;S. Iwamoto
中科院分区：
文献类型：
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作者：
K. Seiwa;K. Masaka;M. Konno;S. Iwamoto
同种负距离依赖幼苗死亡率和负密度依赖幼苗存活率（CNDD）是物种多样性维持的重要机制。最近的研究表明，种子丰富的物种的CNDD更大，主要是由于密度依赖性病原体的攻击。如果种子数与种子大小呈负相关，则种子较小的物种将表现出更大的负CNDD。我们探讨了CNDD是否受种子大小的影响。我们评估了强度的CNDD作为一个对数响应比的概率之间的死亡率在同种和异种网站和高密度和低密度的函数的距离和密度，分别在种子播种实验中使用8种硬木在温带森林在北方日本。作为距离的函数，病原体引起的CNDD与低密度下的种子质量呈正相关，但在高密度下不相关，而种子质量与无脊椎动物或脊椎动物食草动物引起的CNDD不相关。作为密度的函数，种子质量与归因于病原体或无脊椎动物或脊椎动物食草动物的CNDD无关。大种子物种的能力，以更好地容忍CNDD提出了一种新的机制，通过种子大小可能有助于CNDD的变化，并促进物种共存，由于距离依赖性的病原体，特别是那些轴承叶病的攻击。
Conspecific negative distance dependent seedling mortality and negative density-dependent seedling survival (CNDD) are among the most important mechanisms of species diversity maintenance. Recent research has demonstrated that CNDD is greater for species with abundant seeds, due mainly to attack by density-dependent pathogens. If seed number were correlated negatively with seed size, species with smaller seeds would exhibit much greater negative CNDD. We explored whether CNDD is affected by seed size. We evaluated the strength of CNDD as a log response ratio of the probability of mortality among seedlings at conspecific and heterospecific sites and at high and low densities as functions of distance and density, respectively, in a seed-sowing experiment using eight hardwood species in a temperate forest in northern Japan. As a function of distance, CNDD attributable to pathogens was correlated positively with seed mass at low density, but not at high density, whereas seed mass was not correlated with CNDD attributable to invertebrate or vertebrate herbivores. As a function of density, seed mass was not correlated with CNDD attributable to pathogens or invertebrate or vertebrate herbivores. The ability of large-seeded species to better tolerate CNDD suggests a novel mechanism through which seed size may contribute to CNDD variation and promote species coexistence due to distance-dependent attack by pathogens, particularly those bearing leaf diseases.