Meres and Mosses are local names given to the unusual wetlands of Shropshire, Cheshire, Staffordshire and North Wales.

What is a Mere?

Meres were formed at the end of the last Ice Age, c. 12,000 years ago. Most of the UK was buried deep under a thick ice sheet, often up to 1 kilometre thick. As the climate got warmer, the ice started to melt. The ice sheet did not melt in a nice, even, gentle way - but quite rapidly, with huge chunks of ice falling onto the landscape below.

Often these chunks of ice, of all different shapes and sizes, would become buried in soil, mud and other materials being dropped by the melting ice sheet. As the buried chunk of ice melted underground, the materials covering it slumped into a hollow depression, forming a large, deep hole in the landscape with steep sides.

These holes are called “Kettle Holes” as they resemble the impression left by a huge kettle put down in the landscape. These Kettle Holes quickly filled with water, initially from the melting ice, but as time went by, other water filled the holes - from rain, and water from underground springs.

The Kettle Holes are still here today, a landscape legacy that is over 10,000 years old! The water-filled hollows are great for wildlife, as the water feeding them from the surrounding landscape brings with it nutrients, or food for plants and animals.

Local people call these Kettle Holes “Meres”- often beautiful lakes with distinctive plants and animals. If you look at a map of the area, you will find that there are hundreds of these Meres dotted all over the region.

Globally however, these Meres are unusual. They can only be found in ancient glacial landscapes affected by melting ice, and which are in parts of the countryside still undisturbed and wet enough to support them.

What is a Moss?

A Moss is a local name for a Lowland Raised Bog, quite a distinctive name for a very unusual part of our local countryside. Lowland Raised Bogs started their lives at the end of the last Ice Age, just like the Meres described above.

As the Ice Sheet melted 12,000 years ago, shallow depressions, of all shapes and sizes were revealed in the landscape. Sometimes, small pieces of ice became buried in the material left by the ice sheet, but they did not form deep, steep-sided kettle holes.

Water soon filled these shallow depressions and plants and animals made them their home. Mud and debris gradually filled up these quagmires, cutting off the food-rich ground water supply.

Now the only water filling these shallow depressions in our landscape is rainwater.

Rainwater is naturally acidic (a bit like lemon juice!), which means that the only life supported in these areas has to be able to cope with difficult, acidic conditions.

Sphagnum Moss (pronounced sf-ag-num, or spag-num) is an amazing plant. It loves acidic wetlands and will grow quickly in suitable conditions, adding to the acidity of the habitat as it grows. Sphagnum took next to no time in covering the new shallow depressions and in doing so, soaked up lots of the rainfall; holding water at the surface, like a giant puddle.

As it soaks up rainwater, the sphagnum mosses swell up, often to 15 times their original size! This extraordinary feat results in the depression actually rising up above the surrounding landscape, forming an upside-down bowl shape in the countryside, called a Lowland Raised Bog.

The soil, or peat, that makes up bogs is the consistency of black custard and the domes can often tower up to 8 metres above the surrounding countryside. (J Daniels, “Fenn’s, Whixall and Bettisfield Mosses National Nature Reserve”, English Nature 2002)