1. Multiple disturbances can have mixed effects on biodiversity. Whether the interaction of sequential disturbances drives local extinctions or promotes diversity depends on the severity of biomass reductions relative to any stabilizing and/or equalizing effects generated by the disturbance regimes.
2. Through a manipulative mesocosm experiment, we examined how warming events in the fall and simulated grazing disturbance (i.e. clipping) in the winter affected the density, biomass and genotypic diversity of assemblages of the clonal seagrass Zostera marina.
3. We show that the interaction of the two disturbance types reduced density and biomass to a greater degree than warming or clipping alone.
4. The genotype with the highest biomass in the assemblage shifted under the different experimental regimes such that the traits of winners were distinct in the different treatments. The favouring of different traits by different disturbances led to reduced evenness when a single disturbance was applied, and enhanced evenness under multiple disturbances.
5. We conclude that sequential disturbances can alter the outcome of inter‐genotypic interactions and maintain genotypic diversity in clonal populations. Our study expands the context in which disturbance can influence intraspecific diversity by showing that fluctuating selection may result from the sequential application of different disturbance types and not simply seasonal changes in a single agent.

中文翻译：

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顺序干扰改变了克隆植物中基因型间相互作用的结果

1. 多种干扰可能对生物多样性产生多种影响。相继干扰的相互作用是驱动局部灭绝还是促进多样性，这取决于生物量减少的严重性，相对于干扰机制所产生的任何稳定和/或均衡效应。
2. 通过操纵性的中观宇宙实验，我们研究了秋季的变暖事件和冬季模拟的放牧干扰（即修剪）如何影响无性海草Zostera marina组合的密度，生物量和基因型多样性。
3. 我们表明，与单独变暖或削波相比，这两种干扰类型的相互作用在更大程度上降低了密度和生物量。
4. 在不同的实验方案下，组合中具有最高生物量的基因型发生了变化，从而使优胜者的性状在不同的处理方法中各不相同。不同干扰对不同性状的偏爱导致在施加单一干扰时降低了均匀度，而在多重干扰下则提高了均匀度。
5. 我们得出的结论是，顺序性干扰可以改变基因型间相互作用的结果，并保持克隆人群的基因型多样性。我们的研究通过显示波动的选择可能是由于不同干扰类型的连续应用而不仅仅是单一因素的季节性变化，从而扩大了干扰可能影响种内多样性的背景。