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There is an urgent need for transformational change in global and UK agriculture. Current practices undermine the long-term future of farming and impoverish ecosystems in the UK and elsewhere. However, change is not happening at the scale and pace which is needed. Work by David Abson, drawing on ideas by Donella Meadows, explored this failure of progress and proposed a research agenda focused on transformational leverage points which influence sustainability. These points are centred on three realms of leverage: reconnecting people to nature, restructuring institutions and rethinking how knowledge is created and used in pursuit of sustainability. In this paper, these ideas are explored through a combined researcher/stakeholder workshop focused on transformational change in UK livestock systems. Workshop participants were asked to discuss and identify potential levers of change under the three realms identified by Abson. The multiplicity of levers identified and the interactions across realms emphasise the need for new kinds of knowledge creation which are highly transdisciplinary, as well as emphasising the complexity of levers which are likely to play a role in the transformation of livestock food systems in the UK and elsewhere. [ABSTRACT FROM AUTHOR]

Peatlands are globally important stores of soil carbon (C) formed over millennial timescales but are at risk of destabilization by human and climate disturbance. Pools are ubiquitous features of many peatlands and can contain very high concentrations of C mobilized in dissolved and particulate organic form and as the greenhouses gases carbon dioxide (CO2) and methane (CH4). The radiocarbon content (14C) of these aquatic C forms tells us whether pool C is generated by contemporary primary production or from destabilized C released from deep peat layers where it was previously stored for millennia. We present novel 14C and stable C (δ13C) isotope data from 97 aquatic samples across six peatland pool locations in the United Kingdom with a focus on dissolved and particulate organic C and dissolved CO2. Our observations cover two distinct pool types: natural peatland pools and those formed by ditch blocking efforts to rewet peatlands (restoration pools). The pools were dominated by contemporary C, with the majority of C (~50%–75%) in all forms being younger than 300 years old. Both pool types readily transform and decompose organic C in the water column and emit CO2 to the atmosphere, though mixing with the atmosphere and subsequent CO2 emissions was more evident in natural pools. Our results show little evidence of destabilization of deep, old C in natural or restoration pools, despite the presence of substantial millennial‐aged C in the surrounding peat. One possible exception is CH4 ebullition (bubbling), with our observations showing that millennial‐aged C can be emitted from peatland pools via this pathway. Our results suggest that restoration pools formed by ditch blocking are effective at preventing the release of deep, old C from rewetted peatlands via aquatic export. [ABSTRACT FROM AUTHOR]

Recognition of peatlands as a key natural store of terrestrial carbon has led to new initiatives to protect and restore them. Some afforested bogs are being clear‐felled and restored (forest‐to‐bog restoration) to recover pre‐afforestation ecosystem function. However, little is known about differences in the peat properties between intact, afforested and restored bogs. A stratified random sampling procedure was used to take 122 peat cores from three separate microforms associated with intact (hollows; hummocks; lawns), afforested and restored bogs (furrows; original surface; ridges) at two raised and two blanket bog locations in Scotland. Common physical and chemical peat properties at eight depths were measured in the laboratory. Differences in bulk density, moisture and carbon content between the afforested (mean = 0.103 g cm−3, 87.8% and 50.9%, respectively), intact (mean = 0.091 g cm−3, 90.3% and 51.3%, respectively) and restored bogs (mean = 0.095 g cm−3, 89.7% and 51.1%, respectively) were small despite their statistical significance. The pH was significantly lower in the afforested (mean = 4.26) and restored bogs (mean = 4.29) than the intact bogs (mean = 4.39), whereas electrical conductivity was significantly higher (mean: afforested = 34.2, restored = 38.0, intact = 25.3 μS cm−1). While significant differences were found between treatments, effect sizes were mainly small, and greater differences in pH, electrical conductivity, specific yield and hydraulic conductivity existed between the different intact bogs. Therefore, interactions between geographic location and land management need to be considered when interpreting the impacts of land‐use change on peatland properties and functioning. [ABSTRACT FROM AUTHOR]

In the UK most large reservoirs constructed for public water supply are in upland areas and situated in catchments that contain at least some organic-rich soils. Dissolved organic matter (DOM) leaching from these soils imparts a brownish colour to water and raises treatment challenges for the water industry since excessive post-treatment concentrations result in the generation of potentially harmful disinfection by-products in drinking water. The primary method for maintaining sufficiently low predisinfection DOM concentrations is chemical coagulation, but in the past 15 years water companies have increasingly considered the capacity for catchment interventions to improve raw water quality at source, reducing the need for costly and complex engineering solutions in treatment works. There remains considerable uncertainty around the effectiveness of these catchment engineering-based measures and a comprehensive overview of the research in this area remains lacking. Here we review the peer-reviewed evidence for the effectiveness of four management options for upland organic soil dominated catchments that are being considered by the water industry as options for controlling DOM releases. These are ditch blocking, revegetation, reducing forest cover, and cessation of managed burning. Results of plot scale investigations into effects of ditch blocking on ditch-blocking are available but largely equivocal, while there is a paucity of information regarding impacts at spatial scales of more direct relevance to water managers. ‘The presence of plantation forestry on peat soils is generally associated with increasing DOM concentrations, although canopy removal has little short term benefit and can even further increase concentrations. Although not widely studied, the available evidence suggests that Sphagnum mosses produce DOM that is more easily removed via conventional treatment processes compared to vascular plants such as heather and grass species. We found surprisingly little published research around the extent to which manipulation of in-reservoir processes might be used to mitigate or exacerbate changes in inflowing DOM as part of a catchment management approach. This review concluded that catchment management measures have rarely been monitored with downstream water quality as the focus, and that restoration impacts vary across sites. To mitigate the uncertainty surrounding restoration effects on DOM, measures should be undertaken on a site specific basis, where the scale, effect size and duration of the intervention are considered in relation to subsequent biogeochemical processing that occurs in the reservoir, the treatment capacity of the water treatment works and future projected DOM trends. [ABSTRACT FROM AUTHOR]

Soil piping is an important agent of erosion in many environments, including blanket peatlands. Peatland restoration that aims to reduce erosion has mainly focussed on revegetation and blocking ditches and gullies, rather than reducing erosion from natural soil pipes. However, little is known about the contribution of pipeflow to the fluvial carbon budget of degraded blanket peatlands and whether it is possible to moderate it. In a heavily degraded blanket bog, dissolved and particulate organic carbon (DOC and POC), and water colour, from two catchments were compared before and after half of the pipe outlets in one catchment were blocked. One blocked pipe was monitored for discharge and water quality both pre‐ and post‐blocking as new pipe outlets had formed around the blocked outlet. Both pre‐ and post‐blocking, maximum concentrations of DOC and POC were markedly higher in pipe‐water than stream‐water, with ratios of 1.2 (pre) and 1.3 (post) for DOC, and 4.8 (pre) and 8.8 (post) for POC, rendering pipe‐to‐stream transfer more effective for DOC than POC due to the deposition of POC close to pipe outlets. The increase in DOC and POC flux post‐blocking in both catchments was near‐identical, suggesting pipe outlet blocking was ineffective in reducing fluvial carbon export from pipe networks. Extrapolation of pipe fluxes to catchment scale showed pipes potentially contribute c. 56% of DOC exported by the stream, and that more POC was produced by pipes than was exported by the stream. Our work highlights that pipes need to be considered when seeking to reduce fluvial carbon export in degraded blanket peatlands. [ABSTRACT FROM AUTHOR]