The role of lateral exchange in modulating the seaward flux of C, N, P.

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All living organisms that make up life on Earth are made from a profusion of elements in the periodic table, including trace metals. However, in addition to oxygen (O) and hydrogen (H), the constituents of water, the three most important are Carbon (C), Nitrogen (N) and Phosphorus (P). These have become known as the Macro-Nutrients. These macronutrients are in constant circulation between living organisms (microbes, plants, animals, us) and the environment (atmosphere, land, rivers, oceans). Until human intervention (circa post industrial revolution and even more so since WWII) these 'cycles' were largely in balance: plants took up CO2 and produced O2 and, in order to do so, took up limited amounts of N and P from the environment (soils, rivers) and, on death, this "sequestered" C,N,P was returned back to the Earth. The problem is that human or anthropogenic activity has put these key macro-nutrient cycles out of balance. For example, vast quantities of once fossilised carbon, taken out of the atmosphere before the age of the dinosaurs, are being burnt in our power stations and this has increased atmospheric CO2 by about 30 % in recent times. More alarmingly, perhaps, is that man's industrial efforts have more than doubled the amount of N available to fertilize plants, and vast amounts of P are also released through fertilizer applications and via sewage. As the population continues to grow, and the developing world catches up, and most likely overtakes, the western world, these imbalances in the macro-nutrient cycles are set to be exacerbated. Indeed, such is the impact of man's activity on Earth that some are calling this the 'Anthropocene': Geology's new age. The environmental and social problems associated with these imbalances are diverse and complex; most people would be familiar with the ideas behind global warming and CO2 but fewer may appreciate the links to methane and nitrous oxide or the potential health impacts of excess nitrate in our drinking water. These imbalances are not being ignored and indeed a great deal of science, policy and management has been expended to mitigate the impacts of these imbalances. However, despite our progress in the science underpinning this understanding over the last 30-40 years or so, too much of this science has been focused on the individual macro-nutrients e.g. N, and in isolated parts of the landscape e.g. rivers. To compound this even further, such knowledge and understanding has often been garnered using disparate, or sometimes even antiquated, techniques. Anthropogenic activity has spread this macro-nutrient pollution all over the landscape. Some of it is taken up by life, some is stored, but a good deal of it works its way through the landscape towards our already threatened seas. We need to understand what happens to the macronutrients as they move, or flux, through different parts of the landscape and such understanding can only come about by a truly integrated science programme which examines the fate of the macronutrients simultaneously in different parts of the landscape. Here we will for the first time make parallel measurements, using truly state-of-the-art technologies, of the cycling and flux of all three macronutrients on the land and in the rivers that that land drains and, most importantly, the movement of water that transports the macro-nutrients from the land to the rivers e.g. the hydrology. Moreover, we will compare these parallel measurements across land to river in different types of landscapes: clay, sandstone and chalk, subjected to different agricultural usage in order to understand how the cycling on the land is connected, via the movement of water, to that in the rivers.