No Moor Myths?

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The #NoMoorMyths hashtag was launched by the British Association for Shooting and Conservation (BASC) in 2016 and promoted on Twitter with a series of short YouTube videos under the banner “The truth about grouse shooting”. Here they attempt to explain how it conserves rare heather moorland, increases wildlife, boosts the economy, provides jobs and pulls communities together1.

One of the key claims made is that 75% of the world’s heather moorland is found in the UK. This has been repeated so often that it seems to have become the gospel truth. I have seen it so many times and in so many places now that I almost came to believe it myself. The list of organisations who quote this figure tends, perhaps unsurprisingly, to lean towards those with a vested interest in the management of heather moorland for gamebirds. Usually it is given without citation nor substantiation, so it is worth questioning its origin to determine the veracity of this particular #NoMoorMyth. Over the last few weeks I have been digging around on the internet and talking to a range of knowledgeable people to ascertain exactly where the number comes from and how it has been derived. This short blog summarises what I have found out.

A quick web search can easily return a list of shooting organisations that happily quote the magic 75% figure. The Moorland Association has it right there on its home page, boldly stating:

Rarer than rainforest, the UK has 75 per cent of what is left of the globally recognised expanses, treasured by millions of walkers and wildlife enthusiasts2.

…whilst the British Association for Shooting and Conservation (BASC) states:

The UK is home to 75 per cent of the world’s heather moorland, which as a habitat is rarer than rainforest3.

The Game and Wildlife Conservation Trust (GWCT) is the UK shooting lobby’s charitable research body, and they too quote this figure:

Moorland is one of the UK’s most distinctive landscapes and Britain and Ireland have been called “the world’s greatest moorland countries”. The UK is responsible for 75% of the world’s heather moorland4.

Hyperbole abounds and other organisations using the figure include the Countryside Alliance, the National Gamekeepers Association, You Forgot the Birds, DEFRA and even the RSPB.

Again and again, the 75% figure is trotted out, often alongside the idea that being “rarer than rainforest” somehow makes it a more valued habitat. I have written about this before and point out that while true, being rarer than rainforest is something of a nonsensical fact because by the same logic so are urban areas5. What’s more is that both grouse moors and urban areas are niche manmade habitats, whereas rainforest is a natural habitat, covering such a broad range of both tropical and temperate moist forest biomes, that it makes such a comparison rather pointless.

After asking around my Twitter friends for leads the GWCT said it was from ‘Blanket Mire Degradation’, in a paper by Tallis, Meade & Hulme (1998)6. This turned out to be a dead-end and so I asked Prof Robert Marrs, a heather expert from Liverpool University. He didn’t know, but suggested I contact Dr Isabel Alonso (Senior Specialist in Heathlands for Natural England) and Prof Nigel Webb (former Chair of the Dorset Wildlife Trust and leading heathland expert). Both proved extremely helpful and told me the figure originates from a conference paper by Diemont, Webb and Degn on ‘A Pan European View on Heathland Conservation’ (1996)7. In this paper, the authors use submissions by EU member states under Article 17 of the Habitats Directive on the area of heather-dominated lowland heathland within each state. These are reported as follows:

Country Area of heather-dominated heath (ha)
United Kingdom 58,000
The Netherlands 40,000
Belgium 13,000
SW France 65,000
Germany 4,000
Denmark 70,364
Sweden 93,000
Total lowland heath 343,364
Sub Total for UK plus upland heath 835,650 (from Article 17)
Overall Total 1,121,104

These figures show an overall total of 1,121,104ha which includes all UK heath habitat types submitted to the EU Habitats Directive under Article 17 to give a total UK heather-dominated heath/moorland figure of 835,650ha. This then gives a figure of 74.5% of heather-dominated heathland being accounted for in the UK, which rounded up then gives us the magic 75% figure. Mystery solved surely?

However, the sharp-eyed among you will have noticed that these figures relate to just seven countries in Europe. The list does not include other European countries with significant areas of heather-dominated heathland and moor, nor does it account for areas of heather found outside of Europe: in Asia, North America, Australia and New Zealand, and the islands of the Azores and Falklands. In Europe alone there are other significant areas of heather-dominated heath found in Ireland, Spain, Portugal and Norway, as well as further patches of heath and moor in Finland, Estonia, Iceland, Switzerland, Austria, Italy, Greece and Romania among others which will contain heather along with other dwarf shrub species (see Map 1). The exact figures are hard to assess, however, as there is a natural transition from heather-dominated heath to mire communities in northern Europe (e.g. Sweden, Norway and Ireland) and to Mediterranean shrub communities in the south (e.g. Portugal and Spain) as and where edaphic conditions and management dictate. Nonetheless, if we were to include area estimates for heather-dominated moor and heath for these other countries, the proportion found within the UK, while still significant, would likely be much less than the 75% figure quoted.

EU heather
Map 1. Distribution of heath and moor habitats in Europe (based on CORINE 2018)

Without this blog turning too much into an episode of BBC Radio 4’s ‘More or less’ we still need to dig a little further behind these figures since it all depends on what we mean by “heather-dominated moorland”. In other words, where does heather-dominated moorland begin and end? Being able to answer this is essential if we are to create an accurate figure of just how much and what proportion of this is found in the UK.

A widely used definition for mapping is where heather communities cover more than 50% of the land. These communities are themselves made up of dwarf ericaceous shrub species such as common heather or ling (Calluna vulgaris), cross-leaved heath (Erica tetralix) and bell heather (Erica cinerea). Other non-heather dwarf shrub species may also be represented including bilberry or blaeberry (Vaccinium myrtillus), crowberry (Empetrum nigrum), juniper (Juniperus spp) and gorse (Ulex spp). In the EU Habitats Directive these communities are reported under Article 17 as different heath types including Northern Atlantic Wet Heaths (H4010), Temperate Atlantic Wet Heaths (H4020), European Dry Heaths (H4030), Dry Atlantic Coast Heaths (H4060), Alpine and Boreal Heaths (H4060) and Sub-Arctic Salix spp Scrub (H4080)8.

Satellite imagery backed up with ground-based surveys by trained ecologists can help us map their area and distribution. Map 1 shows the European distribution of heath and moor in the CORINE land cover 2018 (CLC2018) data9. This is based on image classification and mapping and a minimum mapping unit size of 25ha. Map 2 shows the distribution of dwarf shrub heath across the UK in the CEH Land Cover map 2015 (LCM2015) as vegetation that has >25% cover of plant species from the heath family (ericoids) or gorse (Ulex spp). This is also based on image classification and mapping but at a finer resolution of 25metres10.  This is further divided into two classes: heather and heather grassland depending on the density of heather relative to common heath grass species such as moor grass (Molinea spp) and fescue (Festuca spp). This map also includes areas classified as bog (peat soils >0.5m depth) as these also include areas of ericaceous heath but these only dominate where the peat has been drained or dissected by erosion gullies. What we can see from these maps is that distribution of heather moor and heath, even just within Europe, is quite widespread. It ought to be clear that not only is it a complicated picture, but it is also very data- and definition-dependent and therefore not an easy question to answer.

GB heather
Map 2. Distribution of heather habitats in Great Britain (based on CEH Land Cover Map 2015)

A further lead on an alternative source of the magic 75% figure came from a rare citation from a couple of reports by the BASC11 and Countryside Alliance12. They suggest that the figure comes from a conference paper by Nicholas Aebischer (Deputy Director of Research, GWCT) on ‘Driven grouse shooting in Britain’ (2010)13. Nicholas graciously forwarded the paper to me and told me that he had got the figure from a much earlier piece of work by Gimingham, Chapman and Webb on ‘European heathlands’ (1979)14. This is also cited by a later paper by Thompson et al on ‘Upland heather moorland in Great Britain’ (1995)15 and although they don’t quote the 75% figure themselves, they do reproduce a map from Gimingham, Chapman and Webb. This shows the approximate location and extent of the European distribution of heather (Calluna vulgaris) dominated upland moorland (see Map 3). This is very much a sketch map and if it is truly the source of the 75% figure is cannot be relied upon because it is very approximate and only refers to Europe. Furthermore, the apparent confusion between upland versus lowland heather and where the line is drawn only serves to muddy the waters and plunges us into some very confusing mists.

Map 3
Map 3. European distribution of heather-dominated upland moorland (after Gimingham et al. 1979)

The big difference between the UK and the rest of Europe (and presumably the world) is that here in the UK the large expanses of heather-dominated moorlands are largely managed for grouse shooting by cutting and burning. These appear as continuous swathes of upland heath across much of the hills of northern England and eastern Scotland. The boundaries of these moors map well onto the grouse estates as shown in the work of Guy Shrubsole at Friends of the Earth16 and the extent of muirburn associated with grouse moor management has been mapped by the RSPB17. Elsewhere heathlands are also managed, largely for and by grazing, without which natural trajectories of succession would tend towards mixed heath and native woodland communities. The uniqueness of the UK heather -dominated moors if one exists therefore is in their management for grouse shooting. The heather clad moors may have existed for many centuries but as the result of forest clearance and subsequent burning, grazing of livestock, cutting of peat and other traditional land management practices. Management for grouse came much later, aided by land ownership, the railways and the invention of the breech loading shotgun.

So, this particular #NoMoorMyth turns out to be a myth itself. The 75% figure is either based on data from just seven European countries or a very rough sketch map. Whichever way you look at it, it is certainly not a global figure since it misses out other countries with significant areas of heather-dominated heath and moor. While we cannot dispute that there are significant areas of heather-dominated moorland within the UK, those organisations using the figure need to do so with care and perhaps better explain its origins and provide more detailed caveats to their intended audience. The only conclusion we can draw at this point is that the claim that “75% of the world’s heather moorland is found in the UK” is both inaccurate and misleading and is in fact likely to be much lower. How much lower we can’t say exactly for the reasons stated, but it is probably less than 50%.

The fact that the large continuous stretches of heather-dominated moor seen in the UK are maintained by intensive land management for driven grouse shooting is not in doubt. Without it, the land currently identified as heather moorland in the UK would likely be very different. Where they weren’t under other land management regimes such as forestry or grazing, they’d be a more fragmented, richer and more varied mosaic of mixed dwarf shrub heath, grassland and native woodland. This would be closer to the potential natural vegetation pattern that you’d expect to see given the prevailing edaphic conditions of soil, topography and climate. However, its current restricted range has resulted in it being listed in Annex 1 of the EU Directive 92/43/EEC on the Conservation of Natural Habitats and of Wild Fauna and Flora, with an obligation on member states to protect it. As we prepare to leave the EU such obligations can be assumed to be redundant. How this then plays out in the greater scheme of conservation and land management interests remains to be seen, but I think we can bet on there being significant areas of heather-dominated moor for years to come, though perhaps not as high as the mythical 75% figure would suggest.

Addendum #1

Since publishing this blog a few days ago I’ve had some great feedback from a number of my followers and friends. I’ve clarified a few points in the existing text, but have also been prompted to do some follow up analysis with other datasets, so present these here as additional figures.

The Article 17 submissions are available online via the EU Habitats Directive web pages and provide some more up to date figures for the area of heathland and heather moor. If we just look at Habitat Type H4030 “European Dry Heaths”, which is by far the largest category reported by area, we see that the total reported area for the UK is 893,540ha while the total reported area over the rest of Europe is 1,660,094ha. This gives a percentage in the UK of 35%.

If we look at the EUNIS (European Nature Information System) Level 2 spatial data that maps 62 different land cover classes at 1ha resolution, then of the EUNIS classes that are likely to contain heather and other dwarf shrub species the percentage is much lower at just over 13%. There are of course, problems in using these data because they don’t tell you about the management regime and they don’t tell you whether heather species are dominant, and there are (of course) marked differences across Europe depending where you are. The following table provides the numbers, whilst Map 4 shows the spatial pattern in these four classes. I know the map is hard to read at this scale so I’ve included a zoomed in area for a section of northern areas of UK interest. Note that the numbers for EUNIS Class 33 are several orders of magnitude lower than those for the other three, so don’t be tempted to read too much in the 84% for this class!

EUNIS Class Description UK (ha) Rest of Europe (ha) UK %
17 Raised and blanket bog 1099122 2752019 28.540
31 Arctic, alpine and subalpine scrub 922314 10419258 8.132
32 Temperate and Mediterranean-montane scrub 1541924 10805458 12.488
33 Temperate shrub heath 57672 10948 84.045
Total 3621032 23987683 13.116
EUNIS heather
Map 4. Distribution of EUNIS classes likely to contain heather spp.
EUNIS heather UKzoom
Map 5. Zoom in to northern areas of interest for UK and Ireland

Addendum #2

In a further twist to this tale, the GWCT have published a clarification of the 75% claim. They now say the figure is limited to the uplands of Europe and have written a short blog “How much upland heather moorland is in the UK?” to clarify their logic19.

The bottom line is that they cite definitions of heather moorland and upland from the paper by Des Thompson and colleagues15 and their use of the rough sketch map from Gimingham et al (1979)14 as proof stating “we believe the true proportion of upland heather moorland found in the UK is likely to be in the region of 75%. The exact percentage is not known and would be helpful. However, it is unlikely to materially influence the overall debate about moorland management.”

So, there you have it. The sole argument supporting the 75% claim is because of a rough 40-year-old hand-drawn sketch map, and because we (the GWCT) say so. However, the GWCT’s blog suggests that an exact percentage would be helpful, though immaterial to the debate.

To add yet further to the GIS analysis, if we just use the EUNIS data on the distribution of land cover types containing heathers and other dwarf shrub species within the height bands quoted by Thompson et al as defining upland then we can perhaps see something of the true distribution of upland heather. The proportion of these heather-containing land cover types represented within the UK above the 300m contour defining upland from the Thompson et al paper are as follows:

Raised and blanket bogs – 42.8% or 4423km2

Arctic, alpine and subalpine scrub – 6.7% or 7250km2

Temperate and Mediterranean-montane scrub – 7.7% or 6861km2

Temperate shrub heathland 97.8% or 268km2

Total – 9.1% or 18805km2

These are calculated again from EUNIS data on habitat types https://eunis.eea.europa.eu/about which is itself derived from Natura2000, satellite imagery, IUCN and the CDDA under the auspices of European Biodiversity data centre (BDC) and the EU 25m resolution digital elevation model to identify land above the 300m contour. As Thompson et al acknowledge, the definition of upland vegetation is highly variable depending on latitude, topography and management, and their combined effect on soils, climatic envelopes, exposure/shelter, microclimates, etc. The 300m+ contour is therefore highly generalised to the UK and across the rest of Europe will tend to underestimate areas in northern latitudes, while overestimate in southern latitudes.

To conclude, I humbly suspect that the impetus for the GWCT blog was the very same blog you’re reading now, but with no direct reference to what I’ve written I can’t be sure. Nonetheless, the percentages that GWCT would find helpful are contained herein if they are minded to look. The fact that they haven’t or don’t acknowledge this analysis suggests to me that they are just concerned with maintaining this convenient soundbite. The map from Gimingham et al. is certainly not one to derive any kind of statistic from. It is simply a hand-drawn sketch map and not a source of scientific information.

Addendum #3

Eventually! The Game and Wildlife Trust’s “What the Science Says” fact-checker has looked into this and concluded that the claim that 75% of the world’s heather moorland is in the UK is unsubstantiated. They say…

“The figure that 75% of the world’s heather moorland, or upland heather moorland (quoted differently in different places), is found in the UK has been repeated by many organisations over recent decades. However, the two occurrences that we found in the scientific literature were not supported by the citations given. We are not aware of published scientific work that determines what percentage of the world’s upland heather moorland is held in the UK.”

See here for the full article.

Thanks to Andy Baird, Graeme Swindles, Joe Holden, Isabel Alonso, Nigel Webb, Rob Marrs, Nicholas Aebischer, Guy Shrubsole and others for providing information. And thanks to Miles King, David Eyles, Rachael Unsworth, Adrian Colston and others for helpful comments on the blog itself.

References and links:

  1. https://www.youtube.com/results?search_query=%23NoMoorMyths
  2. http://www.moorlandassociation.org/ (The MA have as of April 2020 updated all their web pages with the new figure of “75% or Europe’s upland heather moorland is found in the UK” but you can still see the old web pages courtesy of The Way Back Machine web archive here: https://web.archive.org/web/20191230143837/https://www.moorlandassociation.org/
  3. https://basc.org.uk/grouse/grouse-the-landscape/
  4. https://www.gwct.org.uk/policy/consultation-responses/evidence-submission-to-the-2016-petitions-committee-inquiry-into-grouse-shooting/protecting-habitat-and-species/
  5. https://countrysquire.co.uk/2016/11/25/right-to-reply-to-those-who-shoot/
  6. Tallis, JH., Meade, R., & Hulme, PD. (1998) Introduction. in J.H. Tallis, R. Meade, P. D. Hulme (Eds.), Blanket Mire Degradation, Proceedings, British Ecological Society, Manchester; 1-2.
  7. Diemont, WH., Webb, N., & Degn, H J. (1996). A Pan European View on Heathland Conservation. In Proceedings National Heathland Conference, 18-20 September 1996, New Forest, Hampshire; 21-32.
  8. http://archive.jncc.gov.uk/default.aspx?page=4060
  9. https://land.copernicus.eu/pan-european/corine-land-cover
  10. https://www.ceh.ac.uk/services/land-cover-map-2015
  11. https://basc.org.uk/download/67954/
  12. https://www.countryside-alliance.org/CountrysideAlliance/Media/News/2016/05/BACKGROUND-NOTE-ON-GROUSE-SHOOTING-HEATHER-AND-PEATLAND-MANAGEMENT-Fe…-2.pdf
  13. Aebischer, N., Ewald, J. & Tapper, S., 2010. Driven grouse shooting in Britain: A form of upland management with wider conservation benefits. In: Proceedings of the World Symposium on Hunting Activities: Ecologic and Economic Benefits of Hunting. The World Forum on the Future of Sport Shooting Activities, pp. 186–201.
  14. Gimingham, C.H., Chapman, S.B. & Webb, N.R. (1979). European heathlands. In: Specht, R.L. (ed.) Ecosystems of the World, Vol. 9A. Heathlands and Related Dwarf Shrublands, pp. 365-413. Elsevier, Amsterdam.
  15. Thompson, D. B. A., MacDonald, A. J., Marsden, J. H., & Galbraith, C. A. (1995). Upland heather moorland in Great Britain: a review of international importance, vegetation change and some objectives for nature conservation. Biological Conservation, 71(2), 163-178.
  16. https://friendsoftheearth.uk/maps/grouse-moors.html
  17. Douglas, D. J., Buchanan, G. M., Thompson, P., Amar, A., Fielding, D. A., Redpath, S. M., & Wilson, J. D. (2015). Vegetation burning for game management in the UK uplands is increasing and overlaps spatially with soil carbon and protected areas. Biological Conservation, 191, 243-250.
  18. http://muirburncode.org.uk/wp-content/uploads/2016/08/Douglas-et-al-Burning-for-Game-Management-2015-1.pdf
  19. https://www.gwct.org.uk/blogs/uplands-blog/2020/april/how-much-upland-heather-moorland-is-in-the-uk/ 

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