Seed production is critical to the persistence of most flowering plant populations, but may be strongly pollen limited. To what extent long-lived plants can compensate pollen limitation by increasing future reproduction is poorly understood. We tested for compensation in two Dactylorhiza species that differ in reproductive investment by experimentally reducing and increasing pollination in two independent annual cohorts and monitoring demographic responses in the subsequent 2 years for the 2014 cohort and in 1 year for the 2015 cohort. Demographic rates in the second year were significantly affected by pollination treatment in both species, but specific responses differed both between species and years. There was no effect of pollination treatment on demographic responses in the third year. In sum, effects were too weak to make up for the lost reproduction; total fruit production across all 3 years was by far highest in the increased pollination treatment in both species. These results show that long-lived plants do not necessarily compensate for pollen limitation by increasing future reproduction. It further suggests that even periodic declines in pollination rates may have severe demographic consequences, particularly in populations where germination is not density dependent. This has implications for predicting plant population viability in response to changes in pollination intensity.

中文翻译：

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一年中的花粉限制不能通过未来的繁殖来补偿。

种子生产对大多数开花植物种群的持久性至关重要，但可能是花粉受限制的。人们对长寿植物在多大程度上可以通过增加未来繁殖来弥补花粉限制的了解很少。我们通过试验减少和增加两个独立的年度队列的授粉，并监测2014队列的随后2年和2015队列的1年中的两种繁殖力不同的根实物种的补偿，以试验方式减少和增加授粉。授粉处理对这两个物种的第二年人口统计学影响都很大，但是具体响应在物种和年份之间都不同。授粉处理对第三年的人口统计学反应没有影响。总共，效果太弱，无法弥补失去的繁殖；在这两个物种中，经过增强的授粉处理，这三年中的水果总产量迄今为止最高。这些结果表明，长寿植物不一定通过增加未来繁殖来补偿花粉限制。它进一步表明，即使授粉率的周期性下降也可能造成严重的人口后果，特别是在发芽与密度无关的人群中。这对于预测植物种群对授粉强度变化的生存能力具有影响。它进一步表明，即使授粉率的周期性下降也可能造成严重的人口后果，特别是在发芽与密度无关的人群中。这对于预测植物种群对授粉强度变化的生存能力具有影响。它进一步表明，即使授粉率的周期性下降也可能造成严重的人口后果，特别是在发芽与密度无关的人群中。这对于预测植物种群对授粉强度变化的生存能力具有影响。