Community Effects of Competition and Predation across Latitude and Implications for Species Invasions

全球生物多样性格局表明，地球上的大多数物种都出现在热带地区，而出现在高纬度地区的物种明显较少。生物学家预测，物种多样性的这种全球格局很可能是由物种之间的生态相互作用形成的。然而，几乎没有详细的实验数据来证明物种之间的相互作用如何影响从热带到北极的自然群落。因此，存在着一个重要的机会来改变我们对这些基本的物种相互作用如何塑造全球生物多样性格局的理解。此外，这些物种之间的相互作用有很强的潜力限制非本地物种的潜在有害生物入侵，这些入侵往往是通过人类活动运输的，这些活动可能会突破海洋盆地和大陆等历史上的扩散障碍。生物入侵可能造成不良的生态和经济影响，被认为是全球变化的主要驱动力之一。通过对北美和中美洲太平洋沿岸从热带到亚北极的海洋生态系统的广泛实地研究，该项目将研究塑造全球多样性格局和限制生物入侵的生态因素。本科生和研究生以及一名博士后将完全融入研究团队。指导这些初出茅庐的科学家的目标是将科学、专业和跨文化培训整合到一个全面的职业发展框架中，为他们在国际论坛上成功的科学生涯做好准备。研究小组将通过一系列活动进一步提高对海洋和入侵生态的认识，包括针对费城、阿拉斯加和巴拿马的学童和年轻人的外联和教育活动。可用于管理非本土物种的信息将被传播给美国和国际利益相关者的广泛多样性。生物学家长期以来一直在理论上认为，纬度多样性梯度可能是由热带地区比高纬度地区发生的更强的物种相互作用所形成的，例如竞争和捕食。先前的研究表明，低纬度地区的捕食压力确实更大，但尚不清楚捕食和竞争的相互作用如何构建群落，以在生态时间内维持这些多样性格局。这个项目代表了一个国际研究计划，旨在扩大对横跨纬度的物种相互作用的生态学理解。目的是确定两个主要物种的相互作用，竞争和捕食，对物种多样性、群落聚集和对物种入侵的敏感性的相对影响。实地研究将采用大规模实验方法，重点是横跨北纬47度(超过7000公里)的固着海洋无脊椎动物群落。实验将在一年内操纵捕食和竞争的水平，并将在从亚北极到热带的四个地区进行：阿拉斯加、加利福尼亚州、墨西哥和巴拿马。固着海洋无脊椎动物群落，由本地和非本地物种组成，将在不同的捕食和竞争制度下进行迭代检查，以评估群落动态。将评估包括环境条件和招聘率在内的一系列因素对互动结果的相对重要性。

Global patterns of biodiversity demonstrate that most of the species on earth occur in the tropics, with strikingly fewer species occurring in higher-latitude regions. Biologists predict that this global pattern of species diversity is likely shaped by thee ecological interactions between species. Yet few detailed experimental data exist that demonstrate how species interactions influence natural communities from the tropics to the arctic. Therefore, a significant opportunity exists to transform our understanding of how these fundamental species interactions shape patterns of biodiversity across the globe. Furthermore, these species interactions have the strong potential to limit potentially harmful biological invasions by non-native species, which are often transported by human activities that can breach historical dispersal barriers, such as ocean basins and continents. Biological invasions can cause undesired ecological and economic effects and are considered one of the primary drivers of global change. Through extensive field research on marine ecosystems along the Pacific Coast of North and Central America, from the tropics to the subarctic, this project will study ecological factors that shape global patterns of diversity and limit biological invasions. Undergraduate and graduate students and a postdoctoral fellow will be fully-integrated members of the research team. The objective of mentoring these early-career scientists will be to integrate scientific, professional, and cross-cultural training into a comprehensive professional development framework that will prepare them for a successful scientific career in an international forum. The research team will further promote awareness of marine and invasion ecology through a suite of activities, including outreach and educational activities for school children and young adults in Philadelphia, Alaska and Panama. Information that can be applied to the management of non-native species will be disseminated to a wide diversity of U.S. and international stakeholders.Biologists have long theorized that the latitudinal diversity gradient may be shaped by stronger species interactions, such as competition and predation, occurring in the tropics than at higher latitudes. Prior research suggests that predation pressure is indeed stronger at lower latitudes, but it is unclear how interactive effects of predation and competition structure communities to maintain these diversity patterns in ecological time. This project represents an international research program to expand ecological understanding of species interactions across latitude. The objectives are to determine the relative influences of two primary species interactions, competition and predation, on patterns of species diversity, community assembly and sensitivity to species invasion. Field research will employ a large-scale experimental approach that focuses on sessile marine invertebrate communities across 47 degrees of latitude (over 7000 km). Experiments will manipulate levels of predation and competition for one year and will be conducted in four regions, ranging from the subarctic to the tropics: Alaska, California, Mexico, and Panama. Communities of sessile marine invertebrates, composed of both native and non-native species, will be examined iteratively under different predation and competition regimes to evaluate community dynamics. The relative importance of a suite of factors, including environmental conditions and recruitment rates, to interaction outcomes will be evaluated.