DHBlog018 · An article by Robert Sharp
Back in 1967, Peter Hawes, with some colleagues, spent much of the summer on grassland recording the flora. Peter was part way into a study of Dorset’s calcareous grassland that initially spanned from 1967 to 1972 before reappearing in his life 50 years later in 2018. Back in the 1960’s Peter was part of a team from the recently established (1963) Monk’s Wood Experimental Station, in Cambridgeshire. The team leader was Terry “Dry” Wells (focussing on calcareous grasslands) and others included Derek “Wet” Wells (a meadow and wetland specialist), Lynne Farrell and Peter. They were surveying chalk and limestone grasslands in England for the Nature Conservation Review and descended on to a selection of sites in Dorset. Without mobile phones and Health and Safety, there were plenty of adventures and fun, and week after week walking along steep slopes would have benefitted from legs of unequal lengths. The evenings of survey days were spent dining with a pint or three of local ale. The discussions between the leaders taught the youngsters much. Listening, they soon realised the obvious that the superb grasslands they were cataloguing were inherited and created, not with science, but farming. Shepherds had no interest in orchids or blue butterflies, just the production of meat and wool. Flocks of sheep would have grazed an area to the ground and then moved on to a new area - a form of rotational grazing which has since been recommended for reserve management because it can serve the needs of both the flora and fauna. Terry once said in later years ‘The zoologists have had their own way for too long’. What I think he meant was that because invertebrates, notably butterflies, would benefit in the short term from more flowering in spring and summer if grazing was restricted to autumn and winter, management biased towards these periods which would soon lead to the more vigorous grasses not being controlled. This was shown to be so (Hawes, 2015). This attitude sometimes prevails even today!
The Nature Conservation Review was born out of the emerging awareness of two truths: that nature reserves don’t simply look after themselves; and that miracle agrichemicals were killing the countryside. Derek Ratcliffe was involved in understanding these issues, and particularly the impact of DDT on birds of prey. He used this understanding to develop first the Ratcliffe Criteria for assessing Nature Conservation Value, and then to lead the creation of the Nature Conservation Review (NCR). Working at Monk’s Wood with Terry Wells and others, Ratcliffe started the NCR in 1967 and finally published the two volume report in 1977. Subtitled “The selection of biological sites of national importance to Nature Conservation in Britain”, the work was a unique assessment of the state of the country in the late 1960’s. It is probably rivalled in scope only by the National Vegetation Classification work carried out 20 years later. Fieldwork began in the mid 1960s and continued for about a decade.
In total, the Wellses, Hawes, Farrell team visited 23 sites in Dorset and conducted 84 surveys. These involved 1mx1m quadrats assessed for species coverage (using the domin scale). Species richness varied from below 20 to over 50 taxa in a single quadrat and the total number of taxa recorded was 193 including bryophytes and even the odd lichen. Results were recorded on field cards like this:
The sites were a mixed bag of quality but there were many that Terry ran out of superlatives to describe.
Fast forward 50 years and Peter decided to do some of it again to see if much had changed after half a century and if so, how, and why.
In 2018, he gathered a team of local botanists including Robin Walls, Jim White, Rob McGibbon, Andrew Branson, from the Dorset Flora Group and Lucy Ridding from the UK Centre for Ecology and Hydrology at Wallingford (CEH). The CEH is the successor to the Monk’s Wood Experimental Station, which for seemingly internal and external political reasons, was abandoned in 2008 despite an energetic campaign to save it.
The methodology was more or less the same, with domin scores replaced by estimates of percentage cover. The location of the original quadrats could not be exactly repeated, being recorded only somewhere within the National Grid 6 figure 100m square. Lucy suggested that the team record five randomly placed quadrats within each 100m square. GPS may have started in the 1960’s but it was only available to the public from the 1980’s and then with limited accuracy, not to mention the cost of “portable” equipment.
Initial progress in 2018 was slow as parched grasslands in the first summer made recording difficult. Eventually, the team surveyed six sites and recorded a total of 60 quadrats. The resultsare published (Hawes et al, 2022).
Overall, the signals were positive as all six sites had been grazed by sheep or cattle or both. However, there were warning signals too. Although overall species richness was not badly affected across the years, the trend showed a decline in low-growing and light-demanding species such as Euphrasia nemorosa (Common Eyebright), Hippocrepis comosa (Horseshoe Vetch), Leontodon hispidus (Rough Hawkbit), Linum catharticum (Fairy Flax), Lotus corniculatus (Common Bird’s-foot-trefoil), Pilosella officinarum (Mouse-ear-hawkweed), Prunella vulgaris (Selfheal), Thymus polytrichus (Wild Thyme) and Viola hirta (Hairy Violet). By comparison, the winners were the coarse and less palatable grasses including Brachypodium rupestre (Tor-grass), Holcus lanatus (Yorkshire-fog) and Dactylis glomerata (Cock’s-foot).
The main factor bringing about these changes is grazing. Best practice will be agreed when the site is evaluated and objectives are clear. What has emerged from research elsewhere is the need to assess grazing regimes and include all the seasons. For example a shortfall in spring and summer grazing will allow coarse grasses to increase at the expense of the less competitive species and autumn and winter grazing will bring short term benefits to the fauna but will not control scrub. All sites would benefit from monitoring; even just a few strategically placed quadrats located with GPS. Climate change is now an important factor with associated unpredictable seasonal weather. Grazing will need to flexible and not prescriptive to mitigate its effects.
The concerns about chalk grassland are unchanged since Terry Wells visited in the 60’s: management and specifically the lack of appropriate grazing. The problem is largely economic: it doesn’t pay to graze animals on chalk grassland. As ever, it is more complex than that: there are no/few people living on and working the land as they used to, modern breeds of sheep and cattle may not be well-suited to these types of grassland, certainly not once they have been invaded by coarse grasses; and there is no established route to market the products of chalk grasslands that offers an acceptable premium to incentivise farmers.
About Peter Hawes
Peter enjoyed careers with the Nature Conservancy, the Hengistbury Head Field Studies Centre and in ecological consultancy. Since retiring, he has focussed on the management of calcicolous grasslands and published several articles.
References
Peter Hawes. 2015. Sheep grazing and the management of chalk grassland. British Wildlife 27(1): 25–30.
Peter Hawes, Richard Pywell & Lucy Ridding, 2018. Long-term changes in chalk grassland. British Wildlife 29(3): 184–189.
Peter Hawes, Andrew Branson, Lucy Ridding, Robin Walls, Jim White and Rob Mc Gibbon. Calcareous grasslands in Dorset: signals of botanical change. 2022. Conservation Land Management. Vol 20. No 4.
Any thoughts please direct to petertjhawes@outlook.com