The importance of grassland ecosystems

Grasslands account for more than half of the planet’s ecosystems; they are IMPORTANT. Climate change coupled with conversion to cropping or afforestation is threatening them and in turn the wildlife associated with them, for they support some of the world’s most iconic animal species.

We may know of the vast steppe grasslands of Mongolia. These are warming at three times the global average. Less well known is the South American Cerrado where millions of acres of grass and scrubland are being converted into soy monoculture and in the process losing vast areas of the most biologically diverse savannah in the world.

While we naturally think of tree planting as being the route to our ‘carbon salvation’, grasslands are possibly even better at locking-up carbon for the long-term. The roots also bind the soil and prevent erosion as well as providing habitat for wildlife. When farmers ploughed up the American mid-west, a native chief tersely noted ‘wrong side up’! In the 1930s this led to the great dustbowl which stretched from Nebraska to New Mexico.

As a result of climate change we have witnessed, on our television screens, huge forest fires in Australia, California, Spain and elsewhere releasing huge amounts of carbon. When grasslands burn, however, the roots remain and soon produce new shoots and most of the carbon remains locked in the soil.

It is easy to think about this issue on a global scale, but the Sudbury riverside meadows and pastures are ‘doing their bit’ for carbon sequestration and wildlife conservation. Of course, these areas are not grazed by wildebeest or buffalo, but the cattle do precisely the same job and provide locally reared grass-fed beef into the bargain. At present the charity does not have figures relating to soil carbon but a university dissertation may soon provide some useful data.

It is easy to think that climate change only affects other parts of the world. However, the winter of 2020/21 was the wettest on record and large pools of water remained on the surface of Friars Meadow for many months, killing the grass. Although by August the grass had mostly grown back with a predominance of marsh foxtail, the peatland where the water had stood had shrunk so that those areas are now lower than the unaffected parts of the meadow. Of course, this doesn’t matter from a recreational point of view; we can still enjoy the area through the summer for picnics, barbeques and walking the dog but the peat shrinkage undoubtedly led to some loss of carbon which would not have occurred without the extreme weather conditions.