Recent developments in understanding mast seeding in relation to dynamics of carbon and nitrogen resources in temperate trees
Recent developments in understanding mast seeding in relation to dynamics of carbon and nitrogen resources in temperate trees
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DOI：
10.1007/s11284-017-1494-8
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发表时间：
2017-11-01
影响因子：
2
通讯作者：
Kabeya, Daisuke
中科院分区：
文献类型：
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作者：
Han, Qingmin;Kabeya, Daisuke
在多年生植物群体中同步间歇生产大种子作物的桅杆播种是一种广泛存在并被广泛研究的现象。规模经济已被证明提供了最终的选择因素，推动桅杆的进化，例如，在捕食者饱和授粉效率的假设，但其生理机制仍然知之甚少。资源预算（RB）模型假设，一株植物需要更多的资源开花和结果比它在一年中获得，因此只有花时，存储资源的特定阈值量被超过。尽管RB模型在理论上已经得到了很好的探索，包括资源枯竭和花粉耦合，但支持这些假设的经验数据仍然存在争议。在这里，我们探讨RB模型适用于主导树种的程度，重点是在自然温带森林的碳和氮资源的动态。几乎没有经验证据表明植物使用储存数年的碳水化合物来生产果实;然而，温带树木中的氮储存在桅杆后更常见。本文综述了氮素的内部循环，包括叶片衰老过程中的再吸收、储存和再动员，并讨论了肥大对这些过程的影响。总的来说，碳水化合物和氮显然参与了驱动桅杆播种的近端机制，但决定性资源似乎是物种特异性的。
Mast seeding, the synchronous intermittent production of large seed crops in populations of perennial plants, is a widespread and widely studied phenomenon. Economy of scale has been demonstrated to provide the ultimate selection factor driving the evolution of masting, for example, in terms of the predator-satiation and pollination-efficiency hypotheses; however, its physiological mechanism is still poorly understood. The resource budget (RB) model assumes that an individual plant requires more resources to flower and fruit than it gains in a year, and therefore only flowers when a specific threshold amount of stored resources is surpassed. Although the RB models have been well explored theoretically, including for resource depletion and pollen coupling, empirical data to support these assumptions are still disputed. Here, we explore the extent to which the RB model applies to masting tree species, focusing on the dynamics of carbon and nitrogen resources in natural temperate forests. There is little empirical evidence that plants use carbohydrates stored over several years to produce fruits; however, nitrogen stores in temperate trees are more commonly depleted after masting. We review the internal nitrogen cycle including resorption during leaf senescence, storage and remobilization, discussing the effect of masting on these processes. Overall, carbohydrates and nitrogen are clearly involved in the proximate mechanisms driving mast seeding, but the determinant resource seems to be species specific.