Long Term Changes in the Phosphorus Biogeochemical Cycle
|Date||Tuesday 6 March 2018|
|Time||4:30pm - 5:30pm|
|Presenter||Professor Phil Haygarth|
|Contact||Professor James Brassington|
Professor Phil Haygarth
Lancaster Environment Centre, Lancaster University, UK
Over the years my team’s work at Lancaster University has focused on phosphorus in the land -water continuum and in particular its transfers from agricultural land to water. For well over a decade we were relatively content to study a ‘stationary’ i.e. non-changing system, but more recently have become aware of accelerated changes due to climate change. This tutorial will consider the challenge in determining this, with all the complexities, controversies and uncertainties associated. I will describe work that uses a combination of methods to evaluate the impact of projected climate change on future phosphorus transfers, and to assess what scale of agricultural change might be needed to mitigate these transfers. We combined novel high-frequency phosphorus flux data from three representative catchments across the UK, a new high-spatial resolution climate model, uncertainty estimates from an ensemble of future climate simulations, two phosphorus transfer models of contrasting complexity and a simplified representation of the potential intensification of agriculture based on expert elicitation from land managers. The effect of climate change on average winter phosphorus loads (predicted increase up to 30% by 2050s) will be limited only by large-scale agricultural changes (e.g., 20–80% reduction in phosphorus inputs). I will argue that the global phosphorus cycle is now ‘non-stationary’ and is starting to accelerate with climate change, with implications for long term biogeochemical transfers to oceans.
Professor Phil Haygarth holds the chair in Soil and Water Science at Lancaster University in the UK, and conducts personal research on the interface between soils and freshwaters, with a focus on diffuse (particularly phosphorus) pollution and runoff control. Phil’s research studies the way in which soils can be encouraged to hold phosphorus at an optimal level to supply plants for food production, whist defining conditions that prevent the unwanted leakage to fresh-waterways. The practical impact of his research has been to help the UK government, and others around the world, develop policies that help farmers and catchment managers optimize plant uptake of nutrients but minimize losses to water. Often this involves efforts to reduce runoff energy, which can have dual benefits for both diffuse pollution and flood control.
Sanitized HTML from output session variable