Mast seeding patterns are asynchronous at a continental scale
Mast seeding patterns are asynchronous at a continental scale
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DOI：
10.1038/s41477-020-0647-x
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发表时间：
2020-04-27
期刊：
影响因子：
18
通讯作者：
Koenig, Walter D.
中科院分区：
文献类型：
--
作者：
LaMontagne, Jalene M.;Pearse, Ian S.;Koenig, Walter D.
以前的研究表明，桅杆播种在大尺度上是同步的，但限于数百公里，但这项大陆尺度的研究表明，这些事件是异步的，对广泛的物种产生时空影响。资源脉冲是罕见的事件，持续时间短，幅度高，推动植物和动物种群和群落的动态（1）。桅杆播种可能是陆地生态系统中最常见的资源脉冲类型（2），其特征是多年生植物种群同步和高度可变的种子作物生产（3，4），在分类学和地理学上都很普遍（5），并且通常与营养稀缺有关（6）。大量种子作物（肥大事件）的产量比低种子年份的作物大几个数量级，这导致种子消费者的高繁殖成功率，并对生态系统产生级联影响（2，7）。虽然有人认为桅杆播撒可能在大陆尺度上同步进行（8），但研究主要限于覆盖数十至数百公里的局部区域。此外，夏季温度作为桅杆播种的线索（9），显示了大陆尺度的模式，表现为正负异常的并列，与北方食种子鸟类的入侵运动有关（10，11）。在这里，我们展示了跨空间的桅杆播种模式的同步性的崩溃，导致了大陆尺度的分裂。在一项横跨北美大陆的树种跨越距离大于5,200 km的同步性分析中，我们发现，在距离大于2,000 km时，桅杆播种模式显着不同步（所有P < 0.05）。其他研究表明，随着距离的增加，同步性下降，但同步性没有下降。夏季气温在大陆尺度的时空变化驱动模式的同步在桅杆播种，我们预计，这会影响空间动态的许多种子吃的社区，从昆虫到小型哺乳动物的大规模迁徙模式的北方种子吃鸟类。
Previous studies showing that mast seeding was synchronized at large scales were constrained to hundreds of kilometres, but this continental-scale study shows that such events are asynchronous, driving spatial and temporal impacts for a wide range of species.Resource pulses are rare events with a short duration and high magnitude that drive the dynamics of both plant and animal populations and communities(1). Mast seeding is perhaps the most common type of resource pulse that occurs in terrestrial ecosystems(2), is characterized by the synchronous and highly variable production of seed crops by a population of perennial plants(3,4), is widespread both taxonomically and geographically(5), and is often associated with nutrient scarcity(6). The rare production of abundant seed crops (mast events) that are orders of magnitude greater than crops during low seed years leads to high reproductive success in seed consumers and has cascading impacts in ecosystems(2,7). Although it has been suggested that mast seeding is potentially synchronized at continental scales(8), studies are largely constrained to local areas covering tens to hundreds of kilometres. Furthermore, summer temperature, which acts as a cue for mast seeding(9), shows patterns at continental scales manifested as a juxtaposition of positive and negative anomalies that have been linked to irruptive movements of boreal seed-eating birds(10,11). Here, we show a breakdown in synchrony of mast seeding patterns across space, leading to asynchrony at the continental scale. In an analysis of synchrony for a transcontinental North America tree species spanning distances of greater than 5,200 km, we found that mast seeding patterns were significantly asynchronous at distances of greater than 2,000 km apart (all P < 0.05). Other studies have shown declines in synchrony across distance, but not asynchrony. Spatiotemporal variation in summer temperatures at the continental scale drives patterns of synchrony in mast seeding, and we anticipate that this affects the spatial dynamics of numerous seed-eating communities, from insects to small mammals to the large-scale migration patterns of boreal seed-eating birds.