This month, in the absence of a man with a mower, I did get a chance to have a close look at both the old spoil and restored grassland at Quarrington quarry. Disappointingly, there was nothing in flower on either part of the site but I did get to admire the neatly mown stripes!
I’ve been thinking quite a lot about what is going on here – I can only assume that the restored land was seeded with grass of some sort, alongside whatever seeds were in the topsoil used to cover the spoil itself. Regular mowing will help keep the rank grass in check but the plant assemblage here looks little like what is growing on the thin soil covering the older spoil and bare ground around the site. Though the number of species in flower in August and September on the newly seeded ground was similar to the number flowering on the older spoil, the actual species were quite different.
I wonder why the decision was taken to cover the new spoil with a thick layer of topsoil? Natural England, in their previous ‘English Nature’ incarnation, produced a paper (Management of Bare Ground) emphasising the importance of bare ground in dry grassland habitats such as this. Bare ground warms up quickly in the sun, providing an important microhabitat for invertebrates and reptiles, whose young can develop more rapidly in the warm soil under bare ground than when that ground is covered in vegetation. Loose soil on bare ground also makes life easier for burrowing organisms and allows new seedlings to become established without competition from other, larger plants.
Opportunistic annual plants are generally the first to become established in thin soils which dry out quickly but they are soon followed by a range of small perennials, as long as there is not too much competition from vigorous grasses. I was amazed last year to see the diversity of vegetation on some of the thinnest soils in the adjacent Crowtrees nature reserve and the same is true of the scree slopes at nearby Raisby Hill grassland.
There were still quite a few things in flower, mainly members of the daisy family but harebells and scabious too, on the scrubby verges of the bridleway up to Quarrington Hill, where they had not been hacked back to within an inch of their lives.
With this in mind, I hope the management regime on the recently restored spoil allows space for diversity to develop rather than turning the hillside into a monocultural, green sward.