Natural acidification changes the timing and rate of succession, alters community structure, and increases homogeneity in marine biofouling communities
Natural acidification changes the timing and rate of succession, alters community structure, and increases homogeneity in marine biofouling communities
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DOI：
10.1111/gcb.13856
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发表时间：
2018-01-01
影响因子：
11.6
通讯作者：
Harley, Christopher D. G.
中科院分区：
文献类型：
--
作者：
Brown, Norah E. M.;Milazzo, Marco;Harley, Christopher D. G.
海洋酸化可能会对海洋群落和生态系统动态产生深远的影响，但由于难以在生态系统层面操纵pCO（2）来模拟在许多不同时间尺度上发生的实际波动，因此对其全面影响的了解仍然很少。特别是不清楚处于不同发展阶段的群落对中等规模pCO（2）变化的反应速度，以及如果高pCO（2）在演替中期缓解，过去的酸化效应是否会持续，是否会因pCO（2）压力的缓解而逆转，或者是否会因生物体适应的先前高pCO（2）条件的偏离而恶化。在这里，我们使用沿着浅水火山pCO（2）梯度的相互移植实验来评估高pCO（2）暴露的时间和持续时间的重要性（即，不同演替阶段的离散事件与连续暴露）对底栖污损生物群落定殖和演替模式的影响。我们发现，在酸化网站的继承最初被推迟（少8周的社区变化），但在接下来的4周赶上。这些连续的变化导致了保持或移植到酸化条件下的群落的同质化，并以反映短期和长期酸化历史的方式改变了群落结构。这些群落的变化可能是种间变异对pCO（2）增加和种间相互作用变化的响应结果。高pCO（2）改变了生物膜的发育，使Serpulids在实验结束时在酸化部位表现最好，尽管早期（移植前）pCO（2）对这些蠕虫募集的负面影响仍然可以检测到。海鞘类Diplosoma sp.和Botryllus sp.沉降较晚，对酸化的耐受性较强。总体而言，短暂的和持久的酸化驱动的变化，在生物污损社区，通过过去和最近的曝光，可能有重要的影响生态系统功能和食物网动态。
Ocean acidification may have far-reaching consequences for marine community and ecosystem dynamics, but its full impacts remain poorly understood due to the difficulty of manipulating pCO(2) at the ecosystem level to mimic realistic fluctuations that occur on a number of different timescales. It is especially unclear how quickly communities at various stages of development respond to intermediate-scale pCO(2) change and, if high pCO(2) is relieved mid-succession, whether past acidification effects persist, are reversed by alleviation of pCO(2) stress, or are worsened by departures from prior high pCO(2) conditions to which organisms had acclimatized. Here, we used reciprocal transplant experiments along a shallow water volcanic pCO(2) gradient to assess the importance of the timing and duration of high pCO(2) exposure (i.e., discrete events at different stages of successional development vs. continuous exposure) on patterns of colonization and succession in a benthic fouling community. We show that succession at the acidified site was initially delayed (less community change by 8 weeks) but then caught up over the next 4 weeks. These changes in succession led to homogenization of communities maintained in or transplanted to acidified conditions, and altered community structure in ways that reflected both short-and longer-term acidification history. These community shifts are likely a result of interspecific variability in response to increased pCO(2) and changes in species interactions. High pCO(2) altered biofilm development, allowing serpulids to do best at the acidified site by the end of the experiment, although early (pretransplant) negative effects of pCO(2) on recruitment of these worms were still detectable. The ascidians Diplosoma sp. and Botryllus sp. settled later and were more tolerant to acidification. Overall, transient and persistent acidification-driven changes in the biofouling community, via both past and more recent exposure, could have important implications for ecosystem function and food web dynamics.