Área de Biodiversidad y Conservación, Departamento de Biología y Geología, ESCET, Universidad Rey Juan Carlos, C/ Tulipán s/n, Móstoles, E- 28933, Madrid, Spain.
Am J Bot. 2009 May;96(5):904-11. doi: 10.3732/ajb.0800223. Epub 2009 Apr 13.
According to life-history theory, reproductive investments involve costs in terms of growth, future fecundity, and/or survival. However, studies to date have often failed to detect costs of reproduction, with survival costs among the less documented. We investigated the cost of reproduction in Helianthemum squamatum (Cistaceae), a short-lived perennial of semiarid Mediterranean environments. After experimental flower removal, we evaluated next season's growth, reproduction, and survival of the plants. We also monitored an indicator of plant physiological status (F(v)/F(m)) and leaf nutrient concentration at key phenological stages during reproduction. Survival rate in deblossomed plants was significantly higher than in control plants. As far as we know, this is the first experimental evidence of a survival cost of reproduction in a perennial plant. In contrast, no cost to growth or reproduction was found during the next season, and no significant differences in F(v)/F(m) or leaf nutrients were found between control and deblossomed plants. Helianthemum squamatum's success in semiarid Mediterranean ecosystems seems to rely on a persistent seed bank, combined with a sustained high reproductive output at the expense of survival. We conclude that this strategy might be more common than previously thought among short-lived shrubby plants growing in stressful Mediterranean areas.
根据生活史理论，生殖投资涉及生长、未来繁殖力和/或生存方面的成本。然而，迄今为止的研究往往未能检测到生殖成本，其中生存成本记录较少。我们研究了短命多年生植物半日花（半日花科）的生殖成本，半日花生长在地中海半干旱环境中。在进行了实验性的花朵去除后，我们评估了植物在下一个季节的生长、繁殖和生存情况。我们还在繁殖过程中的关键物候阶段监测了植物生理状况（F(v)/F(m)）和叶片养分浓度的一个指标。去花植物的存活率显著高于对照植物。据我们所知，这是第一个在多年生植物中发现生殖成本的实验证据。相比之下，在下一个季节没有发现生长或繁殖的成本，而且对照植物和去花植物之间的 F(v)/F(m)或叶片养分没有显著差异。半日花在半干旱地中海生态系统中的成功似乎依赖于持久的种子库，以及以牺牲生存为代价的持续高繁殖输出。我们得出的结论是，这种策略在生长在地中海高压力地区的短寿命灌木植物中可能比以前认为的更为普遍。
