We have been getting to know the Little Asby Hawthorn pretty well, visiting repeatedly, day and night, in winter, spring and summer. But what we really need to help us find out more about the land that the Hawthorn stands in, is an expert. In the space of a few hours with botanist Deborah Land from Natural England, we learnt more than we have learnt in a year.
The view from the Little Asby Hawthorn takes in Sunbiggin Tarn, so we begin here. The tarn, sitting as it does on porous limestone, is a rare ‘oligotrophic’ lake, which means it has very low nutrient content. It is one of the features of this local landscape that has won it classification as a Site of Special Scientific Interest (SSSI), but also gives it the European classification of SAC, or Special Area of Conservation. While we stand in a biting wind – surprisingly cold for June – we look at the plants at our feet and find a huge variety and Deborah names a selection for us:
- Pignut, or poor man’s truffle (you can grate its tuber onto salad);
- Sweet vernal grass that gives hay its smell;
- Lady’s mantle, three different species;
- Lady’s bedstraw;
- Eggs and bacon, or birds foot trefoil;
- Blue-green sedges;
- Clover; Mouse-ear hawkbit;
- Salad burnet;
- Rough hawkbit;
- Wild thyme;
- Blue moor grass;
- Meadow vetchling …
Within a few paces we have seen what Deborah calls a mosaic of habitats, from the nutrient rich dunging areas by the wall to the more open land, where heather is growing, and we find our favourite from this year, the delicate bird’s eye primrose. It seems very rich to us but Deborah says that it could be better and getting grazing levels right is an ongoing challenge. Sheep tend to eat heather in the winter, and flowers in the summer, while cattle are less selective and allow the varied habitats to thrive.
‘But there are a lot of features on these sites that make them really interesting,’ says Deborah. ‘It’s limestone with a drift of peat over the top. On the deeper soils, you get heathland, and on the shallower soils, you get limestone grassland. Then you get deeper and shallower soil limestone grassland, which gives rise to different vegetations. The slightly deeper limestone grassland’s quite lush, it has quite a lot of species in it. Then you get the shallow grassland, and you get blue moor grass, seslaria caerula, quite a rare grass.’
She goes on. ‘And there are areas where you have an aquiclude or aquitard, a water-resistant layer between layers of rock that pushes water out, so you end up with springs and flushes and plants like bird’s eye primrose, and delicate little sedges.’
We have yet to wander into the wet fen-type habitat around the tarn and peer into the clear deep waters of some of the springs there, but have been told that some species of snails that live there are remnants from the last ice age. This land holds a lot of history in its flora and fauna.
We gaze at the dark surface of Sunbiggin Tarn, which is fringed with sand-coloured reeds and rushes. We’ve seen reed buntings here before and heard snipe, but today don’t spot any – most of the birdsong we hear comes from meadow pippits and skylarks, and the usual pair of swans are dipping into the tarn’s dark waters for weeds. Deborah shares her concern about nutrient levels in the water rising, although the reason isn’t clear. As a result, more and more reeds are growing around the tarn. The area covered by water is shrinking, steadily.
We walk up towards the tree, noticing different grasses as we go. I am pleased to learn the name for the fine black headed grass that grows in clumps on the rise to the hill – deer sedge. As we walk to the tree we stop and look into the grykes of the limestone pavement. Deborah picks some oxalis (wood sorrel) and offers it to me. I taste the apple flavour. ‘Pack a sandwich with cheese and add this – brilliant! But don’t eat too much, it can kill you, although you would have to eat loads and loads, a whole bowl full!’
While we’re looking at what’s growing, we talk about Deborah’s background. She has worked as an ecologist for twenty years, and has recently taken a Masters degree in climate science. Little Asby Common is one of the areas where she liaises with the commoners in the establishment of agreements under the government’s agri-environment schemes, which set stocking levels with an aim to maintaining income for farmers while boosting biodiversity. We wonder – in Deborah’s opinion, why does boosting biodiversity matter?
‘That’s a good question, one I get asked a lot. The more biodiverse a habitat, the more robust it is against change. In the UK, most of our habitats are what you call plagioclimax habitats. We have two climax communities: bogs and woodlands. Beyond that, everything is held at a certain level through management or grazing. Now we’ve pretty much removed all our natural herbivores and large predators so the main architect of these plagioclimax habitats is humans. If we stand back and do nothing, a lot of these habitats will start to grade towards that climax community, either woodland or bog.
We’re having to think about how we can make sites really robust for the future. And the best way is to make them as biodiverse as possible, so that as climate change happens they have more species that can spread and move. A lot of our habitats have altitudinal zones. Habitats at the very top of mountains, as the temperature gets warmer, there’s nowhere for them to go. They are extremely vulnerable to climate change and we already know we are going to lose some. But you’ve got habitats further down that have the capacity to move up – if they’re not there, there’s nothing to move up in the altitudinal zone. It’s about making everything as biodiverse as possible, and the more biodiverse it is, the more robust it is.’
We peer into the grykes and spot many different plants: hart’s tongue fern, brittle fern, herb robert, limestone fern, wild garlic, spleenwort and dog’s mercury, an ancient woodland indicator. This area has been felled, and grazed, for a long, long time, but the plants tell a story of the long distant past, and show more recent changes as well.
‘What’s really encouraging about this is that five years ago, if you had walked along here, everything would have been nibbled down in the grykes because sheep can access the grykes but the cattle can’t. Now that we’ve reduced the sheep numbers drastically, all of the gryke flora is flourishing.’
We get to the tree – it has taken us a long time because we’ve been talking so much and looking at all the plants on the way. Rob and I hadn’t made a firm guess about the Hawthorn’s age so we’re interested in what Deborah says. She pauses and says it is probably hundreds of years old. I hadn’t expected the estimated figure to be so high. This tree is squat and compact, but its small size tells more about its environment than about its age, which is told, rather, in the gnarls in its bark and the solidity of its trunk. How much longer might it last? This summer’s leaves seem sparse and there were very few flower buds. But because we have only just begun to get to know this tree, we don’t know if that is normal or abnormal for it, and will have to observe it for several more summers before we can gauge its health.
After an hour on the scar we are shivering. The wind is cold, as it so often is up here. Maybe that’s why the tree only puts out a handful of flowers – just enough to satisfy a few hardy insects and birds. Despite the less than balmy climate though, we all agree this is a special place, and Deborah remembers a photograph she took here, many years ago, in mist. She reflects again on why protecting a biodiverse countryside matters.
‘Why does it matter? Look, if you were to live in a city, how much would the countryside matter then? If you go on a holiday, where do you gravitate to? Open water, peaks, trees, single trees. There’s a primeval draw in all of us to come back to wild places, or places that hark back to something right inside, somewhere. Many people have very much lost touch with it, but it’s always there.’
We will be learning from Natural England’s local team at each of the seven trees in the next few months and will share what we learn on our public walks and on this website. We’re looking forward to it.
More about Natural England at https://www.gov.uk/government/organisations/natural-england
More information on Little Asby Common Ecology from this PDF : Little Asby Common Ecology.