The
grassland of a churchyard is usually one of the few remaining scraps of
unimproved sward left in a parish. In Riseley, unimproved grasslands survive
only on Thurleigh Airfield, occasional stretches of road verge and in the
churchyard. Semi-improved grassland is present in several paddocks and along
most of the road verges. These have fewer species of plant because of excessive
poaching, lack of management or past applications of herbicide or fertiliser,
but they have not been reduced to monoculture. Grasslands that are frequently
sprayed or fertilised and which consist of one, or just a few, productive grass
and clover species are called “improved” because of their increased yield.
Species-rich
grasslands are recognised as important habitats not only because of the number
of plants they contain but because of the rich diversity of fungi, insects and
wildlife that they support. In general, the more plant species the more
bio-diversity of wildlife in general. Not only is the number of plant species
important but the way the grass is managed has a large effect on what else lives
there. When all the grass in the churchyard was regularly mown many butterflies,
for example, would not have been able to breed because the caterpillars would
have been destroyed before they could pupate.
To
maintain a rich and diverse grassland it either needs appropriate grazing or
cutting at the right times of year. Treating the conservation area as if a
traditional hay meadow seemed the most sensible option. It is important that we
rake up and remove the grass cuttings to mildly impoverish the soil. The richer
the soil, the fewer plant species usually result, This is because the most
vigorous species can come to dominate if provided with enough nutrient. It is
already possible to see how the structure of the sward is altering with our
“hay cutting” regime.
Elsewhere
in the churchyard the more vigorous grasses tend to dominate. In parts of the
conservation area these grasses are visibly less lush and broadleaved herbs like
Rough Hawkbit, Burnet Saxifrage and Ladies Bedstraw are becoming dominant. The
best time of year to cut, to remove most nutrient, is in early hay cutting time
before most plants have seeded. The only problem is that cutting in midsummer
would disrupt certain insects’ lifecycles, and to maintain populations of most
plants, at least some seeds have to be produced some years. At present we are
cutting most of the area in midsummer but leaving a particularly rich and
attractive block in the middle until the whole area is cut again in autumn.
One of
the most spectacular effects of the conservation management has been the
development of large anthills. Colonies of the yellow meadow-ant have already
shifted many tens of pounds of soil particles to create these most fascinating
of structures. The flora of anthills is a subject in itself- it has been known
for rare amble weeds to thrive in the cultivations caused by ants. Each of our
anthills is developing its own different plant community. Very fine leaved
grasses dominate both the two largest. One is covered in Red Fescue — the
usual fine leaved grass of meadows and lawns. The other has a lookalike grass
which is much overlooked and only considered common on dry railway banks. This
is the Narrow-leaved Meadow Grass.
The hay
cut regime has been good for the buttercups. Although there are some patches of
creeping buttercup (the abundant garden weed), most of the buttercups are more
interesting. There are good populations of the Bulbous, Meadow, and Goldilocks
Buttercups. The latter plant always has some petals undersized or missing.
I have no
idea where the large bush came from, whether planted or bird-sown but it is not
the Common Hawthorn. It is the scarcer Midland (or Woodland) Thorn that grows in
ancient woods and old hedges. The leaves are not so deeply cut and it has two
stones in the haw, which distinguishes it from. Common Hawthorn. My guess is
that a bird brought it from the ancient hedges of Dag Lane in its gut.
The
boundary hedge was laid in December 1997 — this served to make an attractive
feature of a hedge that was starting to look straggly and stag headed with
top-heavy thorns and dead elm suckers. Laying a hedge also creates lots of dense
growth for nesting birds and cover for other creatures. The bare ground exposed
after laying provides opportunities for new plants to establish including trees
and shrubs.
The grass
cuttings and other debris is being thrown into a pile which will gradually rot
back into the ground. The site was chosen under the hawthorn bush where the
grass had already been shaded out and the ground enriched by leaf-fall. This
rotting pile will undoubtedly be home to all manner of small creatures, many of
which we will never even know about. Although piles of debris are useful habitat
in them selves, it would have been a great shame to cover and destroy any of the
grassland. Unimproved grassland has developed over centuries, it is increasingly
rare, and impossible to fully recreate, whereas compost heaps can be built
anywhere and colonise within weeks.
There was
some discussion about introducing additional native wildflowers into the
conservation area. At first sight this would seem a positive development, but
introductions are controversial, It is argued that the natural development of
the habitat is artificially altered, that inappropriate plants might oust
important species already there and that many wildflower seeds are from
unsuitable strains - many imported from the continent. We have played safe do
far, though the possibility of turf transplants from other unimproved grassland
in the parish is not discounted.
It is to
be hoped that this project will continue indefinitely. In the early years of the
current conservation movement projects such as tree planting got much of the
attention. Tree planting is easy to see, easy to quantify and easy to get money
for, but not always of any ecological value. By comparison, managing our ancient
grasslands is more subtle, less spectacular but far more important.
Mark Powell, April 1999