Saturday, 20 October 2012

Making a Meadow on Ivy Green


Species-rich, semi-natural grasslands (e.g. traditional hay meadows) are now some of the rarest habitats in Britain, and they are also some of the most colourful and biodiverse.

Up until the Second World War such grasslands were common – particularly in river valleys. These meadows were full of wild flowers and were at their most glorious in May and June. In late summer they were cut (traditionally using scythes) and the cut grass left to dry in the sun. Once dry, the ‘hay’ was raked into piles, loaded onto horse-drawn carts and dragged away to be stored in barns, eventually to be fed to animals during the winter months.

I don’t suppose many of the old farmers thought too much about the effect they were having on biodiversity (!) Nevertheless, the drying and raking stages helped to spread the wild flower seeds (not to mention the grass seeds) and removing the hay crop kept the nutrient content of the soil on the low side. This may seem counter-intuitive but high nutrient levels lead to the habitat being dominated by a few vigorous species, whereas lower nutrient levels tend to suppress these species whilst giving more delicate species a chance to flourish.

After the Second World War millions of acres of meadowland were ploughed up and planted with crops or turned into species-poor ‘ley’ meadows dominated by Perennial Rye-grass. In the Mersey Valley the ancient meadows were tipped on, turned into golf courses or sports fields or grossly over-grazed by horses. But when I first moved to Chorlton, in the 1970s, there were still small patches of species-rich grassland left, with some of the original meadow flora. The local authorities then committed a series of outrageous acts of crass vandalism by planting trees on many of these precious patches. This was basically a stupid and perverse assault – a bit like gluing a false moustache onto the upper lip of a beautiful woman! It led me to formulate Bishop’s First Law, i.e. an organisation’s knowledge of, or concern for, its local environment is inversely proportional to it propensity to plant trees.   Whenever I walk on Chorlton Ees (i.e. Chorlton Meadows) and see those gloomy, species-poor pseudo-woods that dominate the area now, I mourn for the rich, colourful place that we could have had if the local authorities had known what they were doing.

I have reason to believe that the old local meadows were of a type that ecologists call ‘Alopecurus-Sanguisorba’ – that is meadows dominated by the grass Meadow Foxtail (Alopecurus pratensis)

 and the herb Great Burnet (Sanguisorba officinalis).
A defined suite of other species tend to accompany these two dominant ones. A sad, degraded remnant of such a meadow is still just about visible near Sale Water Park.

I was wandering across Ivy Green, one day last June, admiring a large patch of Meadow Foxtail, and thinking, “wouldn’t some Great Burnet look good with that?” Suddenly I stopped in amazement because with the grasses were a few plants of Great Burnet - in a site where I’ve never recorded that species before! Frankly, I can’t explain how they got there and how I had previously failed to spot them. It occurred to me that here was an opportunity to attempt to re-create a Mersey Valley hay meadow.

I asked the Mersey Valley Wardens if they could strim the area in late summer or early autumn. They did so, and then last Sunday (13.10.2012) members of FoCM raked off the hay. This wasn’t too easy because, after all the rain recently, the hay was sodden (luckily we weren’t planning feed it to any animals). One of our members said that raking this soggy mess reminded him of combing the knots out of one of his children’s tangled hair.

Although two of the appropriate species are present on our site, many other key species are missing. In the weeks leading up to our hay raking day I had been gathering appropriate seeds from up and down the Mersey Valley. After we had finished raking, and had removed the hay, I mixed these seeds with some dry sand and broadcast the mixture over the site.

Species I chose included some more Great Burnet plus Bistort, Meadow Buttercup, some vetches and Red Clover and two dandelion look-a-likes: Common Catsear and Autumn Hawkbit. Most important, I added seeds of Yellow Rattle (Rhinanthus minor). This plant is a ‘hemi-parasite’ – which means that although its leaves contain chlorophyll and are green, it also attaches itself to the roots of grasses and steals nutrients from them.  This suppresses the grasses and reduces the competition with the more delicate plants.
When attempting a project like this it is extremely important to use local seed and not any old imported ‘wild flower mix’. Perhaps I’ll get round to explaining why in a future post. Suffice it to say that, contrary to popular opinion, planting any old ‘wild flower’ seeds in the countryside can be as damaging to local biodiversity as planting the wrong trees in the wrong place.

So, will all of this effort pay off? We’ll have to wait at least until next May to find out – watch this space!
Dave Bishop, October 2012