SMOKE ON WATER
a vast amount of carbon, which may be released as CO 2 or much more potent but shorter-lived methane and nitrous oxide (Hodgkins et al., 2013; Voigt et al., 2017). Climate change alters the carbon cycle within intact and degraded peatlands. Moisture protects peat from being broken down. Warmer conditions speed up this decay and dry out peatlands at a faster rate. Likely climate changes across the world include increases in mean surface temperature, more intense dry seasons, changes in the cloud cover patterns, increased rainfall and fire frequency (Charman et al., 2013). Drained peatlands are already much drier and will be less resilient to the impact of these changes. Keeping peatlands intact is thus a key strategy to increasing ecosystem-based resilience and adaptation to climate change. There is some evidence from existing degraded sites that under a warming scenario, permafrost peatlands would collapse and be inundated with freshwater. An Arctic fen habitat would develop and begin to form peat again (Swindles et al., 2015). The overall climate implications are uncertain as methane will be released at the same time that carbon dioxide is sequestered. Salination driven by sea-level rise would reduce the ability of peatlands to store carbon, trigger changes in the biota and reduce their capacity to provide ecosystems services on which people depend (Whittle & Gallego-Sala, 2016). Tropical peatlands, especially those across Southeast Asia, are thought to be the most vulnerable to this threat due to subsidence (Whittle & Gallego-Sala, 2016). Nonetheless, the impact of future sea-level rise could be superseded by anthropogenic disturbance of these ecosystems (Whittle & Gallego-Sala, 2016). Economic impacts The unsustainable use of peatlands worldwide has had significant impact on human societies and our economies. These effects are long lasting with a price paid across many generations that largely supersedes the short-term initial benefits of their conversion. Modern economies within the Northern Hemisphere suffered these impacts early, with poverty levels in communities associated with degraded peatlands in Western Europe being often higher than for other agricultural populations (Parish et al., 2008). Today, conflicts continue to arise given the myriad of stakeholders and interests often involved in the use and management of these ecosystems (Parish et al., 2008). Unsustainable use of peatlands is driven by a lack of knowledge and/or recognition of their value as key habitats for wildlife, crucial providers of ecosystem services for human development, but also due to governance issues and the immediacy of land demands (Parish et al., 2008). Agricultural subsidies can also help to overestimate the economic benefit derived from peatland exploitation.
However, subsidence is not just a threat in coastal areas. For example, if drainage channels were to be constructed in the Congo Basin, salt water intrusion would not be an issue, but subsidence would quickly make the area undrainable again. In some countries, large parts of the mineral soils below peatlands have the potential to become acid sulfate soils. Hence, even when flooding in peatland areas does not occur prior to the loss of peat, the exposure of the mineral soil may create acid sulfate conditions, thus rendering all forms of productive land-use impossible. Biodiversity Vegetation clearance, drainage and burning are also major causes of biodiversity loss within peatlands across the world (Osaki & Tsuji, 2016). These practices change ecosystem structure and species composition, reducing their capacity to recover from future disturbance (Turetsky et al., 2014; Osaki & Tsuji, 2016). In the United Kingdom, peatlands have been historically sidelined in the broader quest for economic development. Some argue that without active policy intervention, lowland raised bogs – a priority habitat under the European Habitats Directive – could be lost from the UK entirely (Lindsay, 1993). This would have a devastating impact on endangered wildlife such as the ‘vulnerable’ large heath butterfly ( Coenonympha tulllia ), the ‘rare’ white-faced darter ( Leucorrhinia dubia ) and mire pill beetle ( Curimopsis nigrita ). Their habitat has already suffered rapid destruction from commercial peat extraction and drainage of land for agriculture. Peat extraction for horticultural growing media involves the complete removal of existing vegetation and the steady removal of the peat body (Lindsay, 1993) exposing a moonscape-like landscape denuded of life. An example of this is the Chat Moss bog in Manchester. The license for extraction from the bog ended in the early 2000s, and although the peat mining company applied for further planning permission to continue, it was refused by the local planning authority in 2011 (BBC, 2012). A requirement for the extraction company to restore this site exists, although the site remains in a poor condition. Peatlands in a changing climate Climate change has emerged as a significant threat to peatland ecosystems, because it exacerbates the effects of drainage and increases fire risk (Turetsky et al., 2014). It exposes peatlands currently protected by permafrost to thawing and possible increased methane emissions and loss of carbon, and the associated sea-level rise increases the risks of coastal erosion and salination of freshwater peatlands (Whittle & Gallego- Sala, 2016). While this report focuses on tropical peatlands, it is worth remembering that permafrost peatlands also hold
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