British orchid meadows
Dr Wilson Wall,
During the twentieth century, a great deal of highly biodiverse land has been lost. This is not just meadows such as lowland grassland, but downs, orchards and woodland as well. It has not been lost by being built upon, or even a nominal change of agricultural use. Changes have been more subtle and slow, associated with application of fertilizers and herbicides rather than over enthusiastic use of the plough. If we look back at old regional maps, it is often possible to see that what was once pasture land still is, but now if you visit, it is a desert of ryegrasses (Lolium spp.) which, if left to seed, can reach nearly a metre in height.
In a similar way, a change of forestry from mixed deciduous to conifers results in a huge loss of species. When changes such as these are made, the losses are more or less permanent. Changing the climax vegetation of woodlands back from conifer to deciduous will not automatically result in the resurgence of other woodland species. Those plants which have wind-blown seed may return given time, but many will not.
There is a lot that can be done to restore meadows, but when there has been a major change to the basic botany, or the vegetation has been reduced to a virtual monoculture over a large area, then there is a real problem. While restored areas may regain some species, many will have been eradicated, with no seed stock left to recolonise.
It is true that the size of orchid seed is such that it is easily blown by the wind, the overall density being much reduced by the net-like testa which surrounds and buffers the seed itself. As a method of dispersal, however this is a strategy of limited success. Success of seed dispersal for all plants is dependent upon where the seed lands and for orchids this is especially so. They need the presence of a symbiotic fungus for germination and the early survival of the developing protocorm, up to the point where chlorophyll is produced and photosynthesis commences. This complete dependency on a fungal symbiont has resulted in the simple strategy of producing vast numbers of seeds from each plant. A Common Spotted Orchid will produce about half a million seeds every year for the lifetime of the plant, thereby ensuring that some will survive and prosper. On the basis of this, we can state that if the original plant population has been entirely wiped out, then invasion from outside the region is extremely unlikely.
Before restoring a meadow, it is worth considering the time scale available to us and, more importantly, what the state of the soil is. This latter question will have some influence on the ease with which the process can be carried out. In cases where the improved pasture has been heavily treated with fertilizers, the soil may be ideal for nettles and docks, so sometimes a shortcut is taken by deep ploughing to bring the less productive subsoil up to the surface. This is generally not something to be undertaken lightly, if at all. Another method, which I have seen suggested quite seriously is to use a general, glyphosate-based, herbicide to clear everything and start from scratch. As ideas go, this ranks along with burning your house down to build an extension.
To start the process of restoration in a more genteel way, early introduction of Rhinanthus minor, (Yellow Rattle) should be carried out. This is easily done by seeding and, once established, it will take care of itself, as well as the grass. This annual plant is semi-parasitic on grass and will eventually give the meadow a degree of autonomy from grass.
Yellow rattle provides a very important indication of the state of a meadow.
While reintroducing wild flowers, generally dicotyledonous species, is relatively easy using seed which is readily purchased, this is not so for orchid species. Huge amounts of seed would be required to produce a single adult plant. The only sensible way of reintroducing these marker species is to plant the growing orchid.
It is sometimes assumed that because orchids require their own symbiotic fungus, they will not establish in the surrounding ground and survive if they are introduced minus the fungus. This has often been shown to be incorrect. Most of the mycorrhizal fungal species associated with orchids are ubiquitous members of the soil flora and if the orchids can grow happily, the fungus is also likely to be there, thus allowing seeds to germinate.
The most important starting point, when considering which orchids to introduce into an area, is the ambient light. It is true that most species are very tolerant of a range of conditions. For example, Anacamptis pyramidalis (Pyramidal Orchid) will grow in woodland, but they do tend to be rather leggy, preferring a sunny aspect, and Platanthera chlorantha (Greater Butterfly Orchid) will grow on open fields in full sun, but are often found in woodland.
Anacamptis pyramialis (Pyramidal Orchids) in an open meadow. These are often accompanied by Dactylorhiza fuchsii (Common Spotted Orchids) and
Ophrys apifera (Bee Orchids).
Platanthera chlorantha (Greater Butterfly Orchid) achieve their maximum size when grown in partial shade.
An often overlooked aspect of meadow cultivation is the possibility of producing a small-scale meadow in a back garden. We have considerable experience of this aspect of what is really just small-scale meadow restoration. A lawn can often be regarded as improved pasture, which is ripe for restoration. Hopefully the grass area will not have been heavily treated with what is generically termed ‘weed and feed’. If it has, then its effect will be to kill all those lovely deep- rooted dicotyledonous plants, while stimulating all the grass to grow. It usually takes a while to return a lawn to a better condition, often at least a year, but the result is well worth it. Even small lawns can give an immense sense of achievement when the wild flowers start appearing.
Now, with garden meadows, there are two primary aspects which are of particular interest. The first is that a garden meadow constitutes an ecological island. By this, I mean that anything you introduce will be genetically isolated unless someone up the road also has a garden meadow containing the same species with which your plants can cross-pollinate. The other, which is also an effect of isolation, is that most plants will not turn up by chance. They need to be deliberately introduced. Some, of course, have wind-blown seeds, all the dandelions for example. For many others, such as vetches, the seeds are heavy and do not travel far. Between these two extremes are certain species that are staggeringly successful and widely distributed since they are mainly dependent upon animals eating the fruit and disseminating the seed. Brambles are one such example of this. Orchid seed is rather odd in this respect although the seed is very light and can be wind-blown over considerable distances, the possibility of some alighting in your garden and then growing into a flowering plant is really rather slim.
A small garden meadow with two species of buttercup in full flower, Ranunculus acris (Meadow Buttercup ) and R. bulbosus (Bulbous Buttercup). Most lawns have Bulbous Buttercups present – in this case, the Meadow Buttercup arrived unannounced.
It is interesting that small meadows really do act like islands in that the populations of some species will wax and wane. This is most obvious with clearly active species, such as bumble bees. In small garden meadows, bumble bee nests may come and go on an annual basis, but as the size of the meadow increases, so the rate of fluctuation will decrease, until the area becomes so large that there will always be a bumble bee nest present, or several if you are lucky. In the garden meadow pictured above, Bombus pascuorum, a carder bee, is unusually present. Some years, they make a nest and during others, they are absent. This tendency to fluctuate in numbers on small plots is also true of plants, although as plants are not able to actively search out suitable grassland, the fluctuations can be both extreme and, once at zero, permanent.
One of the ways in which these fluctuations in plants can be kept under control is by timing the cutting of the meadow so that the annual plants have time to set seed before they are cut down. Orchids can handle the occasional early cut as they are perennial plants and will regrow from their root the following year. Since orchids are perennial there can be a slow accumulation of plants over the years which can result in spectacular displays. One such garden meadow is shown in the photographs, where the major species is Dactylorhiza praetermissa (Southern Marsh Orchid).
Garden meadow predominantly containing Dactylorhiza praetermissa (Southern Marsh Orchid). By now well established, there is virtually no grass present in the area, its control being a natural part of the process.
Gardens, such as this one, create such a spectacle that they become local features of interest. By now, the orchids are seeding themselves into what was the lawn and into pots and other areas of this garden and elsewhere locally. So, by developing an area such as this, regardless of its size you can help preserve species and enhance the local biodiversity. The species you choose depends ultimately on the soil, but there is always a native species which will suit your particular situation.