Department of Biology, Tufts University, Medford MA 02155 USA.
Philos Trans R Soc Lond B Biol Sci. 2021 Dec 6;376(1839):20200371. doi: 10.1098/rstb.2020.0371. Epub 2021 Oct 18.
Cyclical fluctuations in reproductive output are widespread among perennial plants, from multi-year masting cycles in forest trees to alternate bearing in horticultural crops. In natural systems, ecological drivers such as climate and pollen limitation can result in synchrony among plants. Agricultural practices are generally assumed to outweigh ecological drivers that might synchronize alternate-bearing individuals, but this assumption has not been rigorously assessed and little is known about the role of pollen limitation as a driver of synchrony in alternate-bearing crops. We tested whether alternate-bearing perennial crops show signs of alternate bearing at a national scale and whether the magnitude of national-scale alternate bearing differs across pollination syndromes. We analysed the Food and Agriculture Organization of the United Nations time series (1961-2018) of national crop yields across the top-producing countries of 27 alternate-bearing taxa, 6 wind-pollinated and 21 insect-pollinated. Alternate bearing was common in these national data and more pronounced in wind-pollinated taxa, which exhibited a more negative lag-1 autocorrelation and a higher coefficient of variation (CV). We highlight the mutual benefits of integrating ecological theory and agricultural data for (i) advancing our understanding of perennial plant reproduction across time, space and taxa, and (ii) promoting stable farmer livelihoods and global food supply. This article is part of the theme issue 'The ecology and evolution of synchronized seed production in plants'.
周期性波动的生殖输出在多年生植物中普遍存在，从森林树木的多年结实周期到园艺作物的交替结实。在自然系统中，生态驱动因素如气候和花粉限制可能导致植物之间的同步性。农业实践通常被认为比可能使交替结实个体同步的生态驱动因素更为重要，但这一假设尚未经过严格评估，对于花粉限制作为交替结实作物同步的驱动因素的作用知之甚少。我们检验了在全国范围内，多年生的、具有周期性结实的作物是否存在周期性结实的迹象，以及在不同授粉综合征下，全国范围内的周期性结实程度是否存在差异。我们分析了联合国粮食及农业组织（FAO）在 27 个具有周期性结实的分类群的主要生产国家的时间序列（1961-2018 年），其中 6 个是风授粉的，21 个是虫媒授粉的。在这些国家数据中，周期性结实很常见，在风授粉的分类群中更为明显，它们表现出更负的滞后 1 自相关和更高的变异系数（CV）。我们强调了将生态理论和农业数据相结合的互惠互利，这对于（i）增进我们对跨时间、空间和分类群的多年生植物生殖的理解，以及（ii）促进稳定的农民生计和全球粮食供应，都具有重要意义。本文是主题为“植物中同步种子生产的生态和进化”的一部分。
