Broitman Bernardo R, Mieszkowska Nova, Helmuth Brian, Blanchette Carol A
National Center for Ecological Analysis and Synthesis, State Street 735, Suite 300, Santa Barbara, California 93101, USA.
Ecology. 2008 Nov;89(11 Suppl):S81-90. doi: 10.1890/08-0635.1.
Studies of the impacts of climate and climate change on biological systems often attempt to correlate ecological responses with basin-scale indices such as the North Atlantic Oscillation (NAO). However, such correlations, while useful for detecting long-term trends, are unable to provide a mechanism linking the physical environment and ecological processes. Here we evaluate the effects of the NAO on recruitment variability of rocky intertidal invertebrates in the North Atlantic examining two possible climate-related pathways. Using a highly conservative test we interpret associations with the NAO integrated over a season (three months) as an indicator of atmospheric effects on newly settled recruits (NAO3), and the effects of the NAO integrated over six months (NAO6) as an indicator of changes in ocean circulation affecting patterns of larval transport. Through an extensive literature survey we found 13 time series, restricted to southwest Ireland and Britain and comprising five species, that could be used for statistical analysis. Significant correlations with NAO3, our proxy for atmospheric effects, were observed in the south-central domain of our study region (southwest Ireland and south England). Significant correlations with NAO6, the proxy for ocean circulation effects, were detected on southwest Ireland. The associations were detected for three (two barnacles and a topshell) at two sites. These results suggest that the NAO can have effects on the recruitment of intertidal invertebrates through different pathways linked to climate and be distributed heterogeneously in space. Based on previous evidence and the sign and geographic location of significant correlations, we suggest that winter NAO effects are likely to occur as a result of effects on the survival of early life stages settling during spring or through changes in phenology. Our results argue that a combination of modeling and synthesis can be used to generate hypotheses regarding the effects of climate on recruitment and aid in the design of field-based tests of explicit ecological mechanisms.
关于气候及气候变化对生物系统影响的研究，常常试图将生态响应与诸如北大西洋涛动（NAO）等流域尺度指标联系起来。然而，这种关联虽然有助于检测长期趋势，但无法提供一个将物理环境与生态过程联系起来的机制。在此，我们评估北大西洋涛动对北大西洋岩石潮间带无脊椎动物补充量变化的影响，研究两条可能与气候相关的途径。通过一项高度保守的测试，我们将一个季节（三个月）内与北大西洋涛动综合相关的指标解释为大气对新定居补充个体的影响指标（NAO3），将六个月内与北大西洋涛动综合相关的指标解释为海洋环流变化影响幼体运输模式的指标（NAO6）。通过广泛的文献调查，我们找到了13个时间序列，这些序列仅限于爱尔兰西南部和英国，包含五个物种，可用于统计分析。在我们研究区域的中南部（爱尔兰西南部和英格兰南部）观察到与我们所代表的大气影响指标NAO3存在显著相关性。在爱尔兰西南部检测到与代表海洋环流影响的指标NAO6存在显著相关性。在两个地点对三种生物（两种藤壶和一种帽贝）检测到了这种关联。这些结果表明，北大西洋涛动可通过与气候相关的不同途径对潮间带无脊椎动物的补充产生影响，且在空间上分布不均。基于先前的证据以及显著相关性的符号和地理位置，我们认为冬季北大西洋涛动的影响可能是由于对春季定居的早期生命阶段存活的影响或物候变化导致的。我们的结果表明，建模与综合相结合可用于生成关于气候对补充影响的假设，并有助于设计基于实地的明确生态机制测试。
