Book Review: Fen, Bog & Swamp

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Annie Proulx is best known as an award-winning novelist. Her numerous awards include the Pulitzer Prize for Fiction for her 1993 novel The Shipping News. Fen, Bog and Swamp, however, is Proulx’s attempt, as a non-scientist, to get to grips with wetlands and how their disappearance contributes to the climate crisis. Focusing solely on those wetlands that produce peat, she reveals how important these habitats are and how we have spent millennia interacting with them, for good or ill.

For Peat’s Sake

Proulx’s decision to focus her book on peat-producing wetlands is in itself, as her subtitle suggests, an indication of how important they are and how big a role their destruction plays in relation to the climate crisis. She first sets out to discover how peat forms, how it holds in so much CO₂ and methane and how we have been altering peat-forming wetlands for centuries. Peat forms from partially rotted and compressed vegetation that has settled in water. Crucially, this water locks out oxygen, preventing further decay and the consequent release of all the CO₂ plant matter contains. Peat also traps methane, making peatlands important carbon sinks.

Somerset Levels peat works — Humans have cut peat for fuel for thousands of years

Scientists now understand that peatlands are more efficient at carbon storage than rainforests. Approximately 3% of the Earth’s land is peatland. Most began to form as the last ice age began to end. Unfortunately, humans have been cutting turf for fuel and draining peatlands to gain farmland for centuries. This drained and damaged land then continues to emit CO₂for years afterwards. Carbon stores become major carbon emitters. Moves to phase out or ban peat sales and restore lost wetlands are obviously positive steps forward. However, because peat takes thousands of years to form, there are no quick fixes.

Fens

Fens are peat-forming wetlands at least partly fed by mineral-rich waters. This water gains its minerals from contact with rocks and soils as it travels via streams and rivers from the uplands to lower-lying areas. The high mineral content is good for reeds, sedges and marsh grasses and the water is usually deep. Proulx focuses on one of the most famous fenlands, the English fens. This area of eastern Britain once covered approximately 15,500²miles. The marshy habitat formed as the land that once linked Britain and Europe, ‘Doggerland’, was inundated around 8,000 years ago. For millennia, humans took advantage of the bounty the fens offered in the form of fish, fowl, reeds for thatching, building and wickerwork and transport routes. They built tracks through the fens, such as the so-called Sweet Track on the Somerset Levels. And they knew this wasn’t a fixed environment, with times of flood that necessitated a move to higher, drier land.

Reeds, sedges and marsh grasses dominate fenland vegetation

However, from the 15^th century on, wealthier landowners began to take over. In East Anglia, they pushed the fenlanders out and large-scale attempts to drain the land began. A rich culture and language were lost. This intensified under James I who brought in experts from the Netherlands. Now, less than 1% of their original extent remains and the reclaimed farmland continues to emit carbon. It also loses its productivity fairly quickly. As the peat dries and erodes, less productive clay soils take over. There is some hope for the future, in East Anglia at least. In 2001, five local and national organisations joined forces for the Great Fen Project. This aims to restore a large area of Cambridgeshire to wetland and wet farming. Not only will this benefit wildlife, but it will also alleviate the risk of flooding in the region.

Ely Cathedral is known as the ‘Ship of the Fens’ because of the way it towers over the flat land

Bogs

Rainfall supplies bogs with water. The lack of a mineral-rich water source means that reeds and sedges can’t survive, and sphagnum mosses dominate instead. Raised bogs can develop from fens. As plant matter builds up over time in water, a central dome forms and material no longer reaches the mineral-rich groundwater. Reeds and grasses can’t survive, and mosses replace them. Peat is typically two to five metres deep. Blanket bogs, meanwhile, form in cooler, more northern climates where there are high levels of rainfall and low levels of evaporation. Peat levels can be up to 10 metres deep. Both types contain huge volumes of sphagnum moss under the surface. These stay moist and don’t decay, once again locking up vast amounts of CO₂.

Raised and blanket bogs once covered large areas of the globe. Humans, though, have severely depleted both over a period of centuries. Turf-cutting and forestry planting have done untold damage. The Flow Country in northern Scotland is one of the largest areas of blanket bog in the world. A period of drainage and coniferous tree planting in the 20^th century, however, threatened its survival. Rare wildlife such as red-throated divers and greenshanks were increasingly vulnerable to predators as the forestry provided cover for them to move in. Fortunately, the trees struggled to flourish. Now, conservationists and landowners are taking out trees and levelling drainage ditches as they restore the area. There is even a bid to get this important landscape recognised as a World Heritage Site.

Flow country — The Flow Country is one of the biggest areas of blanket bog in the world

Swamps

Proulx’s third wetland type is probably the one we in the UK are least familiar with. Despite being permanently waterlogged, swamps are able to support trees and shrubs. It is this woody nature that defines them and makes them different from reedy fens and mossy bogs. Many of North America’s freshwater swamps have their origins in the end of the last ice age as meltwater formed huge lakes. Some swamps then formed as lakes and ponds became overgrown with trees. Alternatively, some freshwater swamps are flooded woods. Saltwater swamps are tropical coastal features, often dominated by mangrove trees. The mangroves not only stabilise the land edge with their roots but produce large amounts of peat and provide a sanctuary for a huge array of wildlife. Remarkably, they are five times more efficient at absorbing carbon than tropical rainforests.

Great sundew — Sundews are common swamp plants

Just as humans have been destroying fens and bogs for centuries, so they have been laying waste to swamps. To European settlers of the 18^th and 19^th centuries, North America’s swamps were an impediment to moving west. Draining them also provided more farmland. Since 1600, it is estimated that about half of the United States’ wetlands have disappeared. With them have gone species such as the ivory-billed woodpecker and Bachman’s warbler. Mangrove swamps are cleared for shrimp farms and coastal development. The destruction of fresh and saltwater swamps has a disastrous impact, though. Like all wetlands, they not only provide valuable wildlife habitat, but they reduce the frequency of wildfires and flooding, store carbon, filter chemical pollutants and heavy metals and contribute to soil formation.

Wetlands for the Future

Knowing how threatened they are, Annie Proulx wanted to understand more about wetlands before they disappear. She also wanted to understand how the loss of peat-forming wetlands in particular is connected to the climate crisis. In this book she aims to communicate the results of this quest. Proulx freely admits that she is the sort of person who likes to find links, even seemingly invisible ones, between things. I did find this approach a bit distracting and hard to follow at times. However, some of her references to art, history and literature are fascinating and prompted my own diversions down various rabbit holes. The section on sphagnum mosses’ preservative nature and how it helps archaeologists was especially interesting. And the book is wonderful at explaining the difference between the various types of wetland.

Islay bog — We are only just realising how important fens, bogs and swamps are

Despite some stories of restoration and attitude changes, this did not feel to me like an optimistic book. In her chapter on the fens, Proulx compares the rising sea levels that inundated Doggerland in the Mesolithic to our own changes in sea level. As she points out, modern Western economic history is largely characterised by our domination over nature as something to be exploited. We are still losing valuable wetlands to a terrifying degree. Ultimately, any attempts at recovery and restoration are simply buying us time.