Now that we all have a bit more freedom to get out and about it seemed like a good time to leave my garden and visit one of the local MWT nature reserves: Roundton Hill near Churchstoke. 

As is the case for many nature reserves, the habitat supports a wide range of species, some familiar and others more unusual and not found in the wider countryside.  Roundton Hill, because of the presence of a number of old mines on the site, is particularly important as a winter roost for Lesser Horseshoe Bats.  There is also a resident pair of Peregrine Falcons which is always an exhilarating bird to watch as well as hear it’s wonderful shrill ‘kek kek kek kek’ call as it flies around the rocky crags.  And the good news is that this bird is an increasingly familiar site in many of our towns and cities too.  Of course, with a location like Roundton, regardless of the wildlife, on a clear day the views from the hill across the surrounding countryside are quite spectacular.  However, I was not aware that Roundton was selected as a SSSI in 1986, for being of outstanding interest for its grass-heath habitat with the presence of ‘spring ephemerals in xerophytic conditions and for its diversity of lichen species’.

If, like me, you are not an expert in botany and plant ecology, your reaction to this revelation is probably somewhere on the ‘so-what’ to ‘whatever’ spectrum.  However, before you click the ‘back’ button on your browser please humour me a bit and continue reading a little longer and you might be surprised.

The challenges of environments with little liquid water (xerophytic)

Living in Wales, especially after the past few winters with all the problems caused by flooding, the last thing you might expect to find is a desert.  Surprising as it may seem, a version of this is exactly what exists on the thin soils and steep craggy faces of Roundton Hill.  Although plenty of rainfall reaches the ground, most of it runs straight off and sun or wind quickly evaporate any that remains.  This means that any plants that grow in this habitat have to be specially adapted to thrive in these conditions.  One of the strategies that many of these plants have adopted is to do most of their vegetative growth in late winter and early spring so that they can take advantage of the increased light and warmer temperatures before the ground completely dries out.  This is the basis for the description of some of the more specialized plants as ‘spring ephemerals’ as they often seem to disappear by the end of the spring.  The other characteristic of plants growing in these areas is that they are often very short either due to adaptation to the lack of water but also as a result of ‘ecotypes’ which are genetically adapted versions of more widespread plants.

The special importance of Roundton Hill

At least 40% of the site supports open acid grassland that has developed on the shallow dry soils associated with the volcanic rock outcrops. This is dominated by grasses such as bents and Sheep’s Fescue, with a range of typical flowering plants including Sheep’s Sorrel, Heath Bedstraw and Parsley Piert.  The xerophytic acid grassland present on the steeper slopes is the largest continuous extent of this habitat type known in Wales.  The acidic grassland over slightly deeper soils on the top of the hill and on other less steep areas is also recognised as being important in the wider context. 

What does this special grassland look like?

The first impression is that it looks like a scruffy bit of lawn with some rocks scattered over the top.  However, when you look more closely, it is clearly very species rich and you start to see the specialist plants that call it home.  The first plant you notice as you walk up the path is a very diminutive version of Hairy Bittercress.  This will be familiar to many gardeners as a weed that always appears on bare soils and amongst gravel.  Seeing this adaptable plant growing here in the harshest of environments you can imagine why it is so good at colonising our gardens.  If you look carefully you may also see another smaller plant with small white flowers and flattened oval seedpods which is much more of a specialist in these dry habitats, Common Whitlowgrass.  Further on you start to encounter other more dry specialized plants associated with the habitat such as Sheep’s Sorrel and Parsley Piert.  Mixed with these are some more floriferous plants such as the Changing Forget-me-not.  This tiny plant, often only three or four centimetres high, has an unfurling flower spike where initially the flowers are a pale creamy yellow but as the spike unfurls and the flowers mature they turn to a more familiar forget-me-not blue.  The leaf rosettes of Mouse-ear Hawkweed are very distinctive as they are covered in silvery hairs which is another common adaptation to reduce water loss from the leaf surface in exposed locations.  Later in the year these rosettes produce distinctive lemon-yellow dandelion like flowers with the outer florets having reddish undersides.  Other more obvious plants are the grey-green spiny leaves of Carline Thistle.  Amongst the new growth you can still see last years seed heads which do not look very different to the new flowers that will appear in summer.  The new flowers are a yellowish brown, and interestingly, during wet weather, the inner bracts fold inwards and hide the flower – a proper sun lover!

More unusual spring ephemerals.   

As well as the typical plants of these habitats there are also a few special plants on the hill but they only occur in a few specific locations and can be very difficult to find especially if you have not seen them before and are not quite sure what to expect.  When we visited the reserve in mid-April, mainly thanks to the eagle-eyes of my wife, Annis, we were lucky enough to find a couple of these ‘species of local distinctiveness and importance’ and they were all near the main paths through the site.  The first one we found was Shepherd’s Cress.  These were much smaller than we expected being only two or three centimetres tall with a cluster of tiny white flowers on the end of a stalk coming out of the centre of a rosette of small pinnate leaves.  However, once you found one it was relatively easy to find other pinheads of white, quite widely scattered across the site.  The rare Small Cudweed was a lot harder to find and, in the end, we only found one plant so we felt very lucky to have seen it.  The other two special plants, Upright Chickweed and Rock Stonecrop, unfortunately eluded us on this occasion but I am sure we will find them on a future visit.

Preserving these special habitats

Although the special plant communities of these unique habitats may appear to some as rather insignificant, once you understand them a little you can begin to marvel at their amazing resilience and the beauty of their adaptation to harsh environments.  You might imagine that by fencing these grasslands within a nature reserve, that they would be protected from the changes that are going on in the wider countryside but unfortunately this is not the case.  We have to remember that the reason for the existence of grassland is a complex interaction between traditional land management and natural or agricultural herbivores together with geological/topographical factors and long-term climate patterns.  Consequently, conserving grasslands is problematic and it is always very difficult to get the balance right.  Most minimally interventionist strategies to manage grassland will result in change, usually in the direction of replacement of the grassland by scrub; therefore, it is essential to actively intervene.  The management objective at Roundton is to maintain and enhance the special dry acidic grassland communities and the approach has been to work with local farmers to ensure sheep graze the grassland to keep it short and also that some cattle are present to reduce encroachment of scrub. 

For the moment it appears that the special xerophytic communities are continuing to flourish. However, in the long-term it is not clear how factors such as climate change or airborne nitrogen pollution from intensified farming, will impact a site like Roundton.  Also, when we visited the site the Rabbit population seems to be booming which may also have an impact on the extent and height of vegetation on the site. 

If you would like more information on the reserve and how to visit it, head to https://www.montwt.co.uk/nature-reserves/roundton-hill.  If you do visit the reserve, please be aware that a considerable amount of tree work has been done on the site which has been necessary to make safe Ash trees that have been damaged by Ash dieback disease (Chalara).  This means that there are lots of piles of wood near the main entrance to the reserve, which to some may seem a bit unattractive, but over time they will become great homes for a wide range of wildlife.  Also, the best areas to see the xerophytic communities are on the upper south facing slopes of the hill which are accessible via a steep and very uneven path that branches left from the main path through the reserve.  If you do wish to visit this area please ensure that you have appropriate footwear and proceed with caution on the steep and uneven sections.  Additionally, please keep to the main paths on the reserve as there are a number of rocky outcrops that are particularly hazardous, especially so during wet weather

Happy wildlife watching

Tim

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