Collaborative Research: Coupled Carbon and Phosphorus Cycling

虽然碳和营养通量之间的关系，以及由此产生的主要生物量的元素比已经合理地研究了浮游系统，碳和不同的营养循环耦合在底栖生态系统中的程度知之甚少。珊瑚礁是底栖生物主导生态系统的绝佳例子，其中碳和营养循环（特别是磷）的耦合可能非常强或非常弱。因此，出现的根本问题是，净碳生产和磷同化的珊瑚礁群落的动力学是否独立被迫，导致在珊瑚礁上的C：P变化很大，或者净碳生产是否只是简单地遵循磷同化率通过C：P比的优势生物量在经典的营养限制模型。该项目将夏威夷大学的两名珊瑚礁生物化学家的专门知识与斯坦福大学的一名流体力学家的专门知识结合起来，以跨学科的方法解决这一问题。 在长达一年的时间里，碳和磷通量将从海水化学成分的变化中测量，这些海水通过夏威夷卡内奥赫湾大堡礁的一个礁坪上的控制体积。第二个目标是更好地了解波浪驱动的水流和斯托克斯漂流在水穿过珊瑚礁的净运输中的基本作用。 这些结果将扩展知识从以前的工作中获得的水槽，其定义的流量特性，只有有限的数据之前，现代仪器的出现，能够解决水流控制体积的边界。 该项目的更广泛影响包括更好地了解底栖珊瑚礁群落的生产力和组成在不同条件下如何变化，因此将为负责将其作为自然资源进行管理的代理人和机构提供有用的知识。该项目还将与现有的海洋大气署方案相互支持，夏威夷大学的科学家参加了该方案，该方案促进和发展整个太平洋区域沿海海洋科学家之间的技术专门知识交流。最后，该项目将为夏威夷大学和斯坦福大学的研究生和本科生提供宝贵的实地经验。

ABSTRACTOCE-0453117Although the relationship between carbon and nutrient fluxes, and the resulting elemental ratio of dominant biomass has been reasonably well-studied for planktonic systems, little is known about the extent to which carbon and different nutrient cycles are coupled in benthic ecosystems. Coral reefs are excellent examples of benthic-dominated ecosystems in which coupling of carbon and nutrient cycles, in particular phosphorus, could be very strong or very weak. Thus, the fundamental question arises of whether the kinetics of net carbon production and phosphorus assimilation by reef communities are independently forced, resulting in widely varying C:P on reefs, or whether net carbon production simply follows rates of phosphorus assimilation through the C:P ratio of the dominant biomass in a classic model of nutrient limitation. This project combines the expertise of two coral reef biogechemists from the University of Hawaii, with that of a hydrodynamicist from Stanford University, in an interdisciplinary approach to resolve this issue. Over a year-long period, carbon and phosphorus fluxes will be measured from changes in the chemical composition of seawater moving through a control volume on a reef flat on the Kaneohe Bay Barrier Reef, Hawaii. The secondary objective is to better understand the fundamental role of wave-driven currents and Stokes drift in the net transport of water across coral reefs. These results would extend knowledge gained from prior work using flumes, with their defined flow characteristics, to the field where there has only been limited data taken prior to the advent of modern instrumentation capable of resolving water flows across the control volume boundaries. The broader Impacts of this project include improving understanding of how the productivity and composition of benthic reef communities vary under different conditions and will, therefore, provide useful knowledge to agents and agencies responsible for their management as natural resources. The project will also find mutual support with an existing NOAA program for which the University of Hawaii scientists are participants that promotes and develops the exchange of technological expertise between coastal marine scientists throughout the entire Pacific region. Finally, this project will provide valuable field experience to graduate and undergraduate students at the University of Hawaii and Stanford University.