Experimental Warming Enhances Effects of Eelgrass Genetic Diversity Via Temperature-Induced Niche Differentiation
Experimental Warming Enhances Effects of Eelgrass Genetic Diversity Via Temperature-Induced Niche Differentiation
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DOI：
10.1007/s12237-020-00827-9
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发表时间：
2020-09-12
影响因子：
2.7
通讯作者：
Stachowicz, John J.
中科院分区：
文献类型：
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作者：
DuBois, Katherine;Williams, Susan L.;Stachowicz, John J.
沿海基础物种的遗传多样性可以增强物种和生态系统对海洋变暖和海洋热浪的适应能力。然而，多样性对生态系统功能的影响往往取决于具体情况，对这种偶然性的机制仍然知之甚少。为了测试沿海基础物种的遗传多样性和恢复力之间的关系升温，我们种植了两个层次的基因型丰富度（1基因型单一或4基因型混合物）的鳗草（大叶藻）盆，并暴露这些盆不同频率的变暖事件（持续或交替）中围隔4个月（仲夏至深秋）。我们的研究结果表明，在单一栽培变暖减少盆生物量的15.8%，但变暖导致的混合物的33.3%的丰产。相比之下，混合物生物量在控制温度下减产13.2%。在持续变暖的混合物Overyielding驱动的正互补性，这似乎是变暖引起的相对性能的基因型随着时间的推移的变化的结果。我们认为，高温胁迫造成了一个权衡，这样，一些基因型经历了更大的光合作用在仲夏，而其他基因型的光限制在晚秋。因此，温度和光照条件的季节性差异在升温处理中产生的基因型峰值性能，从竞争相互作用的基因型释放，并允许通过互补性发生超产量。虽然我们证明了多样性对生态系统功能的影响取决于环境背景以及基因型之间的性状变异，但我们的研究结果强调，保持或恢复遗传多样性可以显着提高沿海基础物种对未来海洋变暖的适应能力。
Genetic diversity within coastal foundation species can enhance species and ecosystem resilience to ocean warming and marine heatwaves. However, the effects of diversity on ecosystem function are often context-dependent and mechanisms underpinning, such contingency, remain poorly understood. To test the relationship between genetic diversity and resilience to warming in a coastal foundation species, we planted eelgrass (Zostera marina) pots at two levels of genotypic richness (1 genotype monocultures or 4 genotype mixtures) and exposed these pots to warming events of different frequencies (sustained or alternating) in mesocosms for four months (mid-summer to late fall). Our results revealed that in monocultures warming reduced pot biomass by 15.8% but warming led to overyielding in mixtures by 33.3%. In contrast, mixture biomass at control temperatures underyielded by 13.2%. Overyielding of mixtures during sustained warming was driven by positive complementarity, which appears to be the result of warming-induced shifts in the relative performance of genotypes over time. We propose that high temperature stress created a tradeoff, such that some genotypes experienced greater photoinhibiton during mid-summer while other genotypes were light limited during the late fall. Thus, seasonal differences in temperature and light conditions in the warming treatment generated asynchrony in genotype peak performance, freed genotypes from competitive interactions, and allowed overyielding via complementarity to occur. While we demonstrate that the effects of diversity on ecosystem function depend on environmental context as well as trait variation among genotypes, our results underscore that maintaining or restoring genetic diversity could dramatically improve the resilience of coastal foundation species to future ocean warming.