Coastal upwelling may strengthen the controls of herbivory and light over the population dynamics of Hedophyllum sessile in the Oregon rocky intertidal
Coastal upwelling may strengthen the controls of herbivory and light over the population dynamics of Hedophyllum sessile in the Oregon rocky intertidal
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DOI：
10.1002/ece3.9218
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发表时间：
2022-08
影响因子：
2.6
通讯作者：
Barbara J. Spiecker;B. Menge
中科院分区：
文献类型：
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作者：
Barbara J. Spiecker;B. Menge
早期生命史阶段的生存对于底栖种群的成功建立至关重要。尽管光照和食草性可能会影响海洋大型藻类在孢子形成阶段通过“招募瓶颈”，但这些因素对大型藻类后续群落模式的相互作用影响尚未得到充分研究。我们通过实验测试了光和放牧对常见潮间带 kelpHedophyllum stesile 孢子体的影响。研究在俄勒冈州海岸的两个地点进行：草莓山（间歇性上升流区域）和布兰科角北（持续上升流区域）。从 2019 年 5 月到 11 月，我们对食草和光照可用性进行了控制，并每月测量海带性能指标（密度和长度）。我们发现，草食和光照可用性的影响在布兰科角北部很明显，但在草莓山则可以忽略不计。在布兰科角北部，食草对H的密度和长度有强烈但相反的影响。无梗。在没有食草动物的处理中，海带密度较高，而在有食草动物的处理中，海带长度较长。不同生活史阶段的反应也不同。食草对幼年海带有负面影响，但对成年海带有正面影响，而光照对幼年和成年海带的长度有相反的影响。遮荫处理中幼海带的长度较高，而无遮荫处理中成年海带的长度较高。我们的研究强调了沿海地球物理过程（以及随后的营养物质）在改变食草动物和光对H. 种群动态影响方面的潜在重要性。无柄，以及这些动态如何进一步受到海带不同特征（即人口特征和生活史阶段）的影响。
Survival of early life history stages is critical to the successful establishment of benthic populations. Although light availability and herbivory are likely to influence the passage of marine macroalgae through a “recruitment bottleneck” at the sporeling stage, the interactive effect of these factors on subsequent community patterns of macroalgae is not well studied. We experimentally tested the effect of light and grazing on sporelings of the common intertidal kelpHedophyllum sessile. Studies were conducted at two sites along the Oregon coast: Strawberry Hill (an intermittent upwelling region) and Cape Blanco North (a persistent upwelling region). Herbivory and light availability were manipulated and kelp performance metrics (density and length) were measured monthly from May to November 2019. We found that the effects of herbivory and light availability were pronounced at Cape Blanco North but negligible at Strawberry Hill. At Cape Blanco North, herbivory had strong but opposing effects on the density and length ofH. sessile.Kelp density was higher in treatments without herbivores while kelp length was greater in treatments with herbivores. Responses also differed with the life history stage. Herbivory had negative effects on juvenile kelp but positive effects on adult kelp while light availability had opposing effects on the length of juvenile and adult kelps. The length of juvenile kelps was higher in shaded treatments while the length of adult kelps was higher in unshaded treatments. Our study highlights the potential importance of coastal geophysical processes (and subsequently, nutrients) in modifying herbivore and light effects on population dynamics ofH. sessile, and how these dynamics may be further influenced by different characteristics of the kelp (i.e., demographic traits and life history stages).