Morphological plasticity as a defense against multiple predators: plasticity in the context of a community

生活在岩石潮间带环境中的物种起源于海洋，但在退潮时必须经常与陆地环境作斗争。因此，这些无脊椎动物和藻类被认为生活在非常接近它们的热耐力极限的地方，气候变化导致的热应激增加可能导致它们的生长、生存和分布模式的改变。最近的生理学研究强调，对许多潮间带生物的热损害主要发生在退潮时的空气暴露期间，此时体温受到多种气候因素的影响。在空中暴露时所经历的温度远远超过潜水时的温度，而且往往与气温有很大的不同。因此，我们从对温度的生理反应到群落尺度过程的推断能力因我们对野外条件下的体温是什么、体温在空间和时间上如何变化以及不同物种之间的模式可能如何变化的有限了解而受到阻碍。Helmuth之前的工作集中在贝类体温的纬度-尺度模式上，这种贻贝是岩石潮间带生态系统中的一种竞争优势。对东北太平洋的测量表明，纬度模式非常复杂，而且由于低潮时间的一致模式，北部地点往往比南部地点更有可能面临高温压力。此外，潮汐制度年际变化的模型表明，在接下来的2？5年，这些北部“热点”的热应力水平可能会接近20？年的最大值。这些结果对我们在何时何地寻找气候变化对潮间带生态系统影响的证据具有重要影响，并表明在不久的将来可能会在几个地点观察到影响。该项目将继续对横跨160个纬度范围的15个地点的温度模式进行研究，并将产生与重要生态潮间带物种相关的连续6年以上的温度记录。这项研究将解决几个明确的预测，源于我之前的研究，关于贻贝体温的空间和时间模式。作为评估这些热应激变化的生态影响的一种手段，赫尔穆斯博士将监测贻贝的地带性高度，并预测北部几个“热点地区”的地带性向下移动。最后，他将应用贻贝的生物物理技术来探索腹足类纽带的热生态，腹足类纽带是贻贝的重要捕食者。该项目在广泛的地理范围内产生了一套独特的温度模式数据集，是目前监测和预测气候变化对东北太平洋潮间带体温潜在影响的最佳手段。由于北部“热点”的暴露时间预计将在未来25年内达到20年的最高值，因此迫切需要保持研究过程中产生的数据流的连续性。广泛影响：作为正在进行的合作的一部分，赫尔穆斯实验室的学生将与K？12教师合作，根据他们的研究、评分标准和评估方案制定教案。具体地说，他们将创建活动，允许学生调查与气候变化、温度对生物体的影响、物种分布模式和潮汐周期动态有关的概念。材料将明确链接到州和国家K？12科学和数学标准，并将发布在一个推广网站上。这位老师将在第一年与Helmuth实验室一起在实地建立实验，并将在研究过程中与小组保持联系。

Species inhabiting rocky intertidal environments are of marine origin, but must regularly contend with the terrestrial environment during low tide. As a result, these invertebrates and algae are thought to live very close to their thermal tolerance limits, and increases in thermal stress due to climate change could lead to changes in their growth, survival, and distribution patterns. Recent physiological studies have emphasized that thermal damage to many intertidal organisms occurs primarily during aerial exposure at low tide, when body temperatures are driven by multiple climatic factors. Temperatures experienced during aerial exposure far exceed those during submersion, and are often substantially different from air temperature. Our ability to extrapolate from physiological responses to temperature to community?scale processes is thus hampered by our limited knowledge of what body temperatures are under field conditions, how body temperatures change in space and time, and how patterns might vary between species.Dr. Helmuth's previous work has focused on latitudinal?scale patterns of body temperatures of the mussel Mytilus californianus, a competitive dominant in rocky intertidal ecosystems. Measurements in the northeast Pacific show that latitudinal patterns are highly complex, and that, because of consistent patterns in the timing of low tides, northern sites are often more likely to be thermally stressful than are southern sites. Furthermore, models of interannual variability in tidal regimes suggest that in the next 2?5 years levels of thermal stress at these northern "hot spots" may be approaching a 20?year maximum. These results have significant consequences for where and when we look for evidence of the effects of climate change in intertidal ecosystems, and suggest that impacts may potentially be observable in the near future at several sites.The project will extend on ongoing study of temperature patterns at 15 sites spanning a 160 range of latitude, and will produce a continuous 6+ year record of temperatures relevant to an ecologically important intertidal species. The study will address several explicit predictions stemming from my previous research, regarding spatial and temporal patterns of mussel body temperatures. As a means of assessing the ecological impacts of these changes in thermal stress, Dr. Helmuth will monitor zonation heights of mussels, and predict downward shifts in zonation at several northern "hot spots." Finally, he will apply biophysical techniques used for mussels to explore the thermal ecology of the gastropod Nucella, and important predator of Mytilus. The project has produced a unique data set of temperature patterns over a wide geographic scale, and is currently the best means available for monitoring and predicting the potential effects of climate change on intertidal body temperatures in the NE Pacific. Because exposure times at northern "hot spots" are predicted to reach a 20year maximum within the next 2?5 years, there is a critical need to maintain the continuity of the data stream that will be produced during the course of this study.Broader Impacts: As part of an ongoing collaboration, students in the Helmuth lab will work with a K?12 teacher to develop lesson plans based on their research, grading rubrics and assessment protocols. Specifically, they will create activities that allow students to investigate concepts related to climate change, the effects of temperature on organisms, species distribution patterns, and the dynamics of tidal cycles. Materials will be explicitly linked to state and national K?12 science and math standards, and will be posted on a outreach website. The teacher will work with the Helmuth lab in the field in year one to set up experiments, and will remain in contact with the group during the course of the study.