Collaborative Research: Environmental Variability, Functional Redundancy, and the Maintenance of Ecological Processes: Experiments in a Model Ecosystem

物种的功能特征是那些决定物种对环境条件的特定反应或它们对生态过程的影响的特征。目前的理论表明，如果群落中有许多物种以相似的方式执行给定的功能，但对环境条件的敏感性不同，则生态系统特性的时间稳定性会更高。所谓的功能冗余应该会导致物种之间的补偿，因为在环境变化的影响下，一些物种会做得更好，而另一些则会做得更差。人为的全球变暖是当前和预期的种群动态、物种相互作用和群落结构从地方到全球范围变化的主要驱动力。因此，生物多样性的变化有可能显著改变重要的生态系统特性，如生产力、养分循环和对干扰或入侵的抵抗力。虽然生态学家通常强调人口和社区对变化的气候平均（例如，温度和降雨量增加）的反应，但全球环流模型也预测，在世界许多地区，极端天气和气候事件的强度、频率和持续时间将显著增加；也就是说，物理环境的可变性增加了。不幸的是，我们目前对日益增加的气候变化对自然生态系统的影响的认识通常相当贫乏。因此，预测社区如何应对不断变化的环境可变性已被认为是一个关键的研究重点。这个项目将促进我们对预测的温度变化如何影响岩石海岸上主要分类群的行为、人口和相互作用的理解。用野外试验验证理论生态预测的模型系统。环境温度强烈影响大多数生物的生理、行为和人口统计，平均温度的变化已经与许多物种的地理范围变化有关。本文将采用一种新的操作技术来测试热变异性变化对一群同类放牧帽贝的生产性能、底栖微藻食物的生产力以及由此产生的两个分类群之间的相互作用强度的影响。营养水平之间的能量转移是与当地食物网支持和养分循环速率相关的关键生态系统过程。本研究不仅将评估热变异性对帽贝生存、生长和放牧活动的物种特异性影响，还将评估随着环境变异性的增加，帽贝物种之间维持生态系统功能的功能冗余的可能性。这项研究产生的数据将为未来调查气候变化对这一多样化和生产性栖息地的影响提供一个框架。更广泛的影响该项目将显著加强加州州立大学长滩分校（CSULB）的研究和教育基础设施，这是一所少数民族（西班牙裔）服务的，主要是本科生的机构。在三年的资助期内，将有至少两名硕士生和12名本科生参与本研究。每个学生将在霍普金斯海洋站度过10周的夏季生活和工作，获得密集的实践研究经验。该项目还将为斯坦福大学的一名博士后科学家提供培训，该博士后将通过积极参与拟议研究的各个方面的开发和实施来获得研究经验和熟练程度。这两个pi都特别致力于为女性和传统上在科学领域未被充分代表的少数民族提供研究经验和机会：丹尼目前的三个学生中有一个是女性，在艾伦实验室工作的四个本科生中，有三个是女性，还有一个是路易斯斯托克斯少数民族参与联盟（LSAMP）研究员。LSAMP计划（部分由NSF资助）旨在提高未被充分代表的学生成功完成科学，技术，工程和数学（STEM）学士学位课程的质量和数量，并增加对研究生学习项目感兴趣，学术资格和录取的学生数量。丹尼将使用这个项目的数据和见解，作为他每年在海洋探索研究所（以前的水生探险）举办的一个密集夏季实地项目中教授的为期一周的“生物力学模块”的一部分。这个项目（部分由美国国家科学基金会资助）旨在让圣地亚哥市中心的高中生对科学感兴趣，并为他们提供进入四年制大学所需的技能。

Functional traits of species are those that determine either species-specific responses to environmental conditions or their influence on ecological processes. Current theory suggests that communities with many species that perform a given function in a similar way but have different sensitivities to environmental conditions will exhibit greater temporal stability of ecosystem properties. So-called functional redundancy should lead to compensation among species, as some will do better when others do worse in response to environmental variability. Anthropogenic global warming is a major driver of current and anticipated changes in population dynamics, species interactions, and community structure from local to global scales. Resulting changes in biodiversity therefore have the potential to significantly alter important ecosystem properties such as productivity, nutrient cycling, and resistance to disturbance or invasion. Although ecologists have typically emphasized the response of populations and communities to changing climatic averages (e.g., increasing temperature and rainfall), global circulation models also predict significant increases in the intensity, frequency and duration of extreme weather and climate events in many parts of the world; that is, increases in the variability of the physical environment. Unfortunately, our current knowledge about the effects of increasing climatic variation on natural ecosystems is generally quite poor. Predicting how communities will likely respond to changing environmental variability has therefore been recognized as a critical research priority.Intellectual MeritThis project will advance our understanding of how projected changes in temperature variability will affect the behavior, demography, and interactions of key taxa on rocky shores ? a model system for testing theoretical ecological predictions with field experiments. Environmental temperatures strongly influence the physiology, behavior, and demography of most organisms, and changes in average temperature have already been implicated in geographic range shifts of many species. A novel manipulative technique will be used to test the effects of changes in thermal variability on performance by a guild of congeneric grazing limpets, the productivity of their benthic microalgal food, and the resulting interaction strengths between the two taxa. Energy transfer among trophic levels is a key ecosystem process linked to local food-web support and rates of nutrient cycling. This research will evaluate not only species-specific effects of thermal variability on limpet survival, growth, and grazing activity, but also the potential for functional redundancy among limpet species to maintain that ecosystem function over time as environmental variability increases. Data generated from this study will provide a framework for future investigations of the consequences of climate change in this diverse and productive habitat.Broader ImpactsThis project will significantly enhance the infrastructure of research and education at California State University, Long Beach (CSULB) - a minority (Hispanic) serving, predominantly undergraduate institution. At least two master's students and twelve undergraduates from CSULB will participate in this study over the three years of funding. Each student will spend ten weeks living and working during the summer at Hopkins Marine Station, gaining an intensive hands-on research experience. This project will also provide training for a postdoctoral scientist at Stanford University, who will gain research experience and proficiency by actively participating in the development and implementation of all aspects of the proposed study. Both PIs are especially committed to providing research experiences and opportunities to women and minorities traditionally underrepresented in science: one of Denny's current three students is a woman, and of the four undergraduate students working in Allen's lab, three are women and one is a Louis Stokes Alliance for Minority Participation (LSAMP) Research Fellow. The LSAMP program (funded in part by NSF) is designed to increase the quality and quantity of underrepresented students successfully completing science, technology, engineering and mathematics (STEM) baccalaureate degree programs, and to increase the number of students interested in, academically qualified for, and matriculated into programs of graduate study. Denny will use data and insight from this project as part of a week-long "biomechanics module" he teaches annually in an intensive summer field program run by the Ocean Discovery Institute (formerly Aquatic Adventures). This program (also funded in part by NSF) seeks to interest inner-city high school students from San Diego in science, and to provide them with the skills needed to gain access to 4-year colleges.