Tracers reveal limited influence of plantation forests on surface runoff in a UK natural flood management catchment

Study region United Kingdom (UK). Study focus Natural flood management (NFM) schemes are increasingly prominent in the UK. Studies of NFM have not yet used natural tracers at catchment scale to investigate how interventions influence partitioning during storms between surface rainfall runoff and water already stored in catchments. Here we investigate how catchment properties, particularly plantation forestry, influence surface storm rainfall runoff. We used hydrograph separation based on hydrogen and oxygen isotopes (2H, 18O) and acid neutralising capacity from high flow events to compare three headwater catchments (2.4-3.1 km2) with differences in plantation forest cover (Picea sitchensis: 94%, 41%, 1%) within a major UK NFM pilot, typical of the UK uplands. New hydrological insights Plantation forest cover reduced the total storm rainfall runoff fraction during all events (by up to 11%) when comparing two paired catchments with similar soils, geology and topography but ∼50% difference in forest cover. However, comparison with the third catchment, with negligible forest cover but different characteristics, suggests that soils and geology were dominant controls on storm rainfall runoff fraction. Furthermore, differences between events were greater than differences between catchments. These findings suggest that while plantation forest cover may influence storm rainfall runoff fractions, it is not a dominant control in temperate upland UK catchments, especially for larger events. Soils and geology may exert greater influence, with implications for planning NFM

The persistence of 'normal' catchment management despite the participatory turn:exploring the power effects of competing frames of reference

Presented as a panacea for the problems of environmental management, ‘participation’ conceals competing frames of meaning. ‘Ladders of participation’ explain insufficiently why public engagement is often limited to consultation even within ‘higher-level partnerships’. This paper distinguishes between: (1) Discourses/practices: (2) Frames and: (3) Power effects, to explain how participation is shaped by frames of reference to produce more or less symmetric exchanges in processes of deliberation. The paper’s empirical focus is the experience of participatory catchment organisations (PCOs) and their central, yet under-researched role in integrated catchment management. In addition to documentary analysis of policy statements, researchers facilitated an international participatory knowledge exchange between four PCOs (and various other agencies), using qualitative methods to record discussions. Results suggest that while statements about legislation promise symmetric engagements, mechanics of legislation frame participation as asymmetric consultation. In their own arenas, PCOs deploy participation within a framework of grassroots democracy, but when they engage in partnership with government, ‘participation’ is reshaped by at least four competing frames: (1) Representative democracy – which admits yet captures the public’s voice: (2) Professionalisation – which can crowd-out framings that facilitate more symmetric engagement: (3) Statutory requirements – which hybridise PCOs to deliver government agendas and: (4) Evidence-based decision-making – which tends to maintain knowledge hierarchies. Nevertheless, PCOs proved capable of reflecting on their capture so, we conclude, for participation to result in more symmetric forms of public engagement the coproduction of science/society, and the power effects of framing, must become explicit topics of discussion in processes of environmental policy deliberation