LTER: Plum Island Sound Comparative Ecosystem Study (Pisces)Effects of Changing land Cover, Climate and Sea Level on Estuarine Trophic Dynamics

河流和流域的人类活动极大地改变了水、沉积物、营养物和有机物等物质输入河口的时间、规模和性质。陆地和沿海水域之间一个重要但被忽视的联系是溶解有机碳和颗粒有机碳和有机氮的输入。这项陆地/海洋边缘生态系统的长期生态学研究（LTER）将重点关注以下问题：由土地覆盖、气候和海平面变化引起的有机质、养分和水通量的变化将如何影响河口的营养结构和初级和次级生产力？该项目通过以下方式来研究这个问题：1)对从陆地、沼泽和海洋进入河口的溶解有机碳和颗粒有机碳和有机氮的通量进行短期和长期测量；2)进行短期和长期操控性实验，以确定营养物和有机物相互作用对通过远洋和底栖食物网的碳和氮流动的影响；3)模拟土地利用变化对食物网转变的影响。该研究将河口生物地球化学与更高营养水平的食物网和种群生物学研究相结合。该研究项目将创造一个精心设计和记录的生态实验和观察的遗产。科研成果数据库将向科学界开放（WWW）。这项研究是建立在马塞诸塞州普拉姆岛海峡和缅因州国家河口研究保护区北湾、南太平洋和威尔斯现有的长期研究记录的基础上的。密集的工作将在梅岛湾进行，并在北湾和井进行具体的比较研究。该研究旨在利用这些系统之间的自然差异来确定无机和有机物质相互作用在控制营养结构、产量和效率方面的重要性。该项目将通过确定不断变化的营养供应如何与有机质的质量和数量相互作用，从而影响河口营养结构，为我们对土地边缘生态系统的理解做出独特的贡献。它还将开发建模方法，将高度可变的物理驱动因素（这里是潮汐、长期海平面上升、河流流入和水循环）与对生态过程的理解联系起来。所开发的动态模型将以各种方式用于预测各种海岸管理办法的影响。例如，有待开发的空间显式模型可用于预测土地利用变化对富营养化和鱼类生产的影响。

Human activities in rivers and watersheds have altered enormously the timing, magnitude and nature of inputs of materials such as water, sediments, nutrients and organic matter to estuaries. An important but neglected linkage between land and coastal waters is the input of dissolved and particulate organic carbon and organic nitrogen. This long term ecological research (LTER) in land/ocean margin ecosystems will focuses on the question-How will trophic structure and primary and secondary productivity in estuaries be affected by changes in organic matter, nutrient and water fluxes caused by changing land cover, climate and sea level? The project examines this question through 1) short and long term measurements of the fluxes of dissolved and particulate organic carbon and organic nitrogen entering estuaries from land, marshes and the ocean, 2) short and long term manipulative experiments to determine the effects of nutrient and organic matter interactions on the flow of C and N through pelagic and benthic food webs, and 3) modeling the effects of land use changes on food web transformations. The proposed research integrates estuarine biogeochernistry with studies of food webs and population biology of higher trophic levels. The research program will create a legacy of well designed and documented ecological experiments and observations. A data base of research results will be accessible (WWW) to the scientific community. The study builds on the existing long term research record at Plum Island Sound, MA, and at the North Inlet, SC and Wells, ME National Estuarine Research Reserves. Intensive work will take place at Plum Island Sound, and specific comparative studies at North Inlet and Wells. The research is designed to take advantage of natural differences between these systems to determine the importance of inorganic and organic matter interactions in controlling trophic structure, production and efficiency. The project will make a unique contribution to our understanding of land margin ecosystems by determining how changing nutrient supply interacts with the quality and quantity of organic matter to affect estuarine trophic structure. It will also develop modeling methods to link highly variable physical drivers, here tides, long term sea level rise, river inflow, and water circulation, with the understanding of ecological processes. The dynamic models developed will be useful in a variety of ways for predicting effects of various coastal management options. For example, the spatially explicit models to be developed can be used to predict the effects of changing land use on eutrophication and fish production.