The Multi-Scale Response of Water Quality, Biodiversity and C Sequestration to Coupled Macronutrient Cycling from Source to Sea

流域研究传统上侧重于水流和水质的科学和管理。近年来，实现良好的生态状况和遵守《水框架指令》一直是优先事项。这一点一直具有挑战性，尤其是因为英国的大多数河流都受到氮、磷的严重污染，包括病原体在内的一系列污染物和来自高地地区的溶解有机碳的转移正在增加。这可能会损害河流和沿海水域的生态，对人类健康构成风险，并增加水务行业的成本。随着国家生态系统评估(2011年)和政府的自然环境白皮书(2011年)的发布，流域管理者面临着更大的挑战，试图确保水资源目标不影响提供一系列监管、供应或文化服务的其他职能，我们都从中受益。提供这些生态系统服务的基础是基本的生态系统过程，例如植物的碳固定和通过分解(碳循环)将碳返回大气，氮和磷等营养物质在植物、土壤、水和大气中的循环，以及包括病原体在内的一系列污染物的解毒。人们对碳、氮、磷(C、N和P)和污染物循环的了解很多，但很少有人研究这些循环在整个景观中的耦合以及随后对自然环境和所提供的服务的影响。为了回应我们目前理解中的这一差距，我们将解决两个研究问题。第一个问题是耦合的大量营养素循环(C、N和P)何时、在哪里以及如何影响流域尺度的景观单元内部和之间的自然环境的功能？第二个问题是，在土地利用、空气污染和气候变化下，这些耦合循环将如何改变，以及在流域和国家范围内对水质、碳固存和生物多样性(三个重要的生态系统服务)将产生什么影响？为了实现这一目标，我们将通过关键过程(净初级生产力、分解、营养循环)来量化C、N和P循环的通量、转化和耦合，并结合有针对性的田间监测和Conwy流域的田间和实验室实验，并辅之以Ribble集约化养殖区的测量，量化与病原体转移和生存能力的联系。预计将取得以下成果：1.量化和改进过程--了解土壤功能类型和加工热点内的C、N、P耦合过程、转化和通量。2.定量研究河流生态系统功能和N/P共限制对淡水富营养化发展的影响。对假设进行检验，即可以在集水和国家尺度上将陆地和淡水生物多样性解释为大量营养素通量和初级生产力的函数。来源到海洋的通量量化和过程--了解病原体的命运和极细沉积物(絮状物)中的大量营养素施加的控制。5.一个综合的、简约耦合的大量营养素(C、N、P)空气-陆地-水模拟平台，配置为横跨Conwy的1公里网格(即增强的Jules模型)。分析碳汇、水质和生物多样性对过去和未来气候、养分和土地(森林)覆盖变化的敏感性，以确定对碳汇、水质和生物多样性过去和未来变化的关键控制。在集水尺度上量化提供碳固存、水质和生物多样性方面的权衡，以及与土地覆盖类型和气候制度的关系。

Catchment research has traditionally been focussed on the science and management of water flow and quality. In recent years, achieving good ecological status and compliance with the Water Framework Directive has been a priority. This has been challenging not least because the majority of rivers in the UK are heavily polluted with nitrogen, phosphorus, and a range of contaminants including pathogens and transfers of dissolved organic C from upland areas are increasing. These can be detrimental to the ecology of rivers and coastal waters, be a risk for human health and increases costs of the water industry. Following the publication of the National Ecosystem Assessment (2011) and the Government's White Paper on the Natural Environment (2011), catchment managers face an even greater challenge trying to ensure water resource objectives do not compromise delivery of other functions which deliver a range of regulating, provisioning or cultural services which we all benefit from. Underpinning delivery of these ecosystem services are basic ecosystem processes such as carbon fixation by plants and the return of carbon back to the atmosphere through decomposition (the carbon cycle), the cycling of nutrients such as nitrogen and phosphorus through plants, soil, water and the atmosphere and detoxification of a range of contaminants including pathogens. Much is known concerning the individual carbon, nitrogen and phosphorus (C, N and P) and contaminant cycles, however the coupling of these cycles through the landscape and the subsequent impacts on the natural environment and the services provided are rarely studied. To respond to this gap in our current understanding we will address two research questions. The first is when, where and how do coupled macronutrient cycles (of C, N and P) affect the the functioning of the natural environment within and between landscape units at the catchment scale? The second is how will these coupled cycles alter under land use, air pollution, and climate-change and what will be the effect on water quality, carbon sequestration and biodiversity (three important ecosyststem services) at both catchment and national scale? To achieve this, we will quantify the fluxes, transformations and coupling of the C, N, and P cycles through key processes (net primary productivity, decomposition, nutrient cycling) and quantify the links to pathogen transfer and viability using a combination of targeted field-based monitoring and field- and laboratory-based experimentation in the Conwy catchment supplemented by measurements in intensively farmed areas of the Ribble. The following outcomes are expected:1. Quantification and improved process-understanding of coupled C, N and P processes, transformations and fluxes across soil functional types and within processing hotspots. 2. Quantification of the effects of instream ecosystem function and co-limitation of N/P on eutrophication development in freshwaters.3. Testing of hypotheses that terrestrial and freshwater biodiversity can be explained at the catchment- and national-scales as function of macronutrient flux and primary productivity.4. Source to sea flux quantification and process-understanding of the fate of pathogens and the controls exerted by macronutrients within very fine sediments (flocs). 5. An integrated, parsimonious coupled macronutrient (C, N, P) air-land-water modelling platform, configured for a 1 km grid across the Conwy (i.e. an enhanced JULES model).6. Sensitivity analysis of carbon sequestration, water quality and biodiversity to past and future climate, nutrient and land (forest) cover change to determine the key controls on past and future changes in carbon sequestration, water quality and biodiversity.7. Quantification of trade offs in delivery of carbon sequestration, water quality and biodiversity at the catchment scale and the relationship to land cover type and climate regime.