BSBI Recorders’ Conference, September 2007 Euphrasia : thoughts on recording and conservation Alan J. Silverside School of Engineering & Science University

BSBI Recorders’ Conference, September 2007BSBI Recorders’ Conference, September 2007

EuphrasiaEuphrasia: thoughts on : thoughts on recording and recording and conservationconservation

Alan J. SilversideAlan J. Silverside

School of Engineering & School of Engineering & ScienceScience

University of PaisleyUniversity of Paisley

Last year’s talkLast year’s talk

Downloadable from:

http://www-biol.paisley.ac.uk/research/Asilverside/masterpage.html

Not exactly an online guide to Euphrasia, but maybe helps.

DevelopmentsDevelopments

UKBAP: the ‘Edinburgh group’

Molecular work in progress:

Christina Oliver (M.Sc. thesis), Graham French (Ph. D. thesis), Jane Squirrell, Peter Hollingsworth, Richard Ennos, Alan Silverside

Overall conclusion so far:

Euphrasia is difficult.


Paper reporting DNA studies (cpDNA, AFLP markers) of a broadly based but necessarily thin survey of British taxa recently submitted.

Diploid species (officinalis, vigursii, rivularis) are genetically well separated from the diploids.

Can be regarded as different lineages which show at least some degree of reproductive isolation from one another.

Photograph shows the waved glandular hairs characteristic of the diploid taxa (in this case E. officinalis subsp. anglica).


Paper reporting DNA studies (cpDNA, AFLP markers) of a broadly based but necessarily thin survey of British taxa recently submitted.

As expected, the tetraploid species are less well differentiated from one another. Morphological entities are generally supported by genetic differences but there are some areas of difficulty.

Existing doubts about E. confusa and E. tetraquetra as genetically cohesive taxa appear confirmed.

“Good” Euphrasia confusa in acid grassland on Dartmoor, but the concept may be a composite taxon.

Note length of grass in this photo – I shall return to this topic


Hybridisation

Current state of account for new book being prepared by Clive Stace:

73 hybrid combinations provisionally accepted

But there is scope for more!

Thoughts on conservationThoughts on conservation

British Euphrasia species are annuals

With seed dormancy they can survive bad years but they require sufficient sites for germination each year and are vulnerable to management changes.

Just short periods of more closed or more rank vegetation can spell extinction for populations.

Particularly critical is grazing.


Already gone, apparently through cessation of grazing:

Euphrasia septentrionalis (Duncansby Head)

The Piltdown Eyebright (Sussex)


Two endemic taxa at serious risk:

Euphrasia vigursii (Devon & Cornwall)

Euphrasia cambrica (N. Wales)


Thoughts about grazing

Think first of abandoned coppice woodland

Coppicing is “unnatural”, but has been the system of management of many ancient woodlands going back to Roman times, if not before.

Abandonment of coppicing has resulted in dramatic loss of diversity in ground flora, insects, the near extinction of the High Brown Fritillary ……….

Coppicing is often essential conservation management.


Thoughts about grazing

Now think of heathland or grassland

Think of some vigorously growing heather, perhaps doing really well after grazing reduction

But if some plants are growing bigger, other plants may well be growing smaller …

And annuals may no longer have germination sites at all …

Euphrasia vigursii

(Dartmoor, 2007)

A diploid, endemic to Cornwall and Devon, generally assumed to have arisen by hybridisation between E. officinalis ssp. anglica and E. micrantha.

It is a plant of damp, grazed heathland, now lost from numerous inland sites, though also persisting on the north Cornish coast.

A surviving plant in under-grazed heathland

Floristics of E. vigursii communities

E. vigursii can survive in very open Ulex gallii / Erica cinerea / Agrostis curtisii, but cannot compete with dense growth of these species. It is primarily a species of the grassy areas between clumps of these species in mosaic communities.

Perhaps the most constant associate is Festuca ovina subsp. hirtula, which forms an open turf in which germination sites remain.

In W. Cornwall, an almost constant associate is Serratula.

Floristics of E. vigursii communities

E. vigursii is commonly said to grow with Agrostis curtisii – and here is a picture to prove it.

But, despite recent published claims supporting this association, E. vigursii generally does NOT grow with A. curtisii, which apparently forms too dense a growth to allow germination of Euphrasia seed.

In this photograph, A. curtisii is invading the existing Festuca ovina turf.

Effects of grazing on E. vigursii

Valuable papers by Hodgson & Baldock (2006) and by Ramsay and Fotherby (2007) relate to a population of E. vigursii at Lydford on Dartmoor (where these photographs were taken).

The area has a long history of grazing (sheep, ponies) but current levels are reduced.

Following the foot & mouth outbreak of 2001, when sheep could not be moved from the site and grazing was unusually heavy, a count of more than 20,000 plants of E. vigursii was recorded in 2002.

In 2003 – 8000 plants

2004 – 97 plants

2007 (brief visit by me) – not counted but very few seen

Effects of grazing on E. vigursii

“Healthy” heathland with vigorous dwarf shrubs may be like abandoned coppice – dominant plants get bigger but others are lost.

At a number of its sites, E. vigursii is at critically small numbers with remaining heathlands often overgrown. Will E. vigursii follow the Piltdown Eyebright?

Conservation of E. vigursii may also require correct floristics information – involving recognition of fescues!

Agrostis curtisii should NOT necessarily be seen as a beneficial associate.


Now to E. cambrica and the myth of ungrazed montane grassland ….

This is NOT E. cambrica

It is E. rhumica endemic to Rhum, where it was described from two rather differing populations. One site is still known, on a montane slope.

Known world population just a few square metres.

Importantly, this slope is selectively grazed by Red Deer, as it no doubt has been for perhaps hundreds of years.

This rather heavy grazing maintains the population.

The deer-grazed habitat of E. rhumica


Large tracts of our mountains of our mountains are grazed by sheep.

But sheep are introduced and “unnatural” ….

Who? Me?


But sheep have been in Britain for 5,000 years.

They may well have helped shape the communities of our mountains and, while ‘restoration’ of montane scrub is undoubtedly of high conservation importance, there is perhaps some undervaluing of grazed montane turf.

There seems even to be an assumption that before sheep there was no grazing …

Meet the Tarpan …

Photo by Kyloe, Wilkimedia Commons (public domain)

Actually the previous photograph is not really a Tarpan as the true Tarpan is extinct, but crosses between Tarpan and the domestic horse survive and have been used in restorative breeding programs.

The Konik Pony, as used here at Wicken Fen, is one such breeding product.


But to return to Euphrasia taxonomy rather than horse taxonomy, it is reasonable to suppose that some of our Eyebrights evolved at the time when Tarpan and other ancient grazing mammals occupied the montane grasslands of the postglacial.

Are they now threatened by ‘restoration’ of ‘natural’ communities that never existed in the first place?

Cwm Idwal, Snowdonia

Montane slopes that must have a very long history of grazing but which are now within a grazing exclosure.

Montane slopes that formerly held a healthy population of Euphrasia cambrica.

Confined to mountains of North Wales.

A very distinct little species, with pale brownish-yellow corollas with incurved lobes; broadly triangular calyx teeth; broad, bluntly toothed, slightly hairy leaves. Rarely hybridises.

Rarer than supposed, due to confusion with E. ostenfeldii, but authentically recorded from at least three different mountains, maybe four.

E. cambrica (on Snowdon)

E. cambrica (on Snowdon)

Euphrasia cambrica

This species has been confused in the past with E. ostenfeldii and it is much rarer than has been thought.

It is reliably recorded from three mountains in Snowdonia and is perhaps also on Cader Idris. The distribution is very much one of a relict species from the early postglacial. However, known populations are highly restricted and the true plant may have been seen recently in as few as two sites.

It requires very short, grazed turf.

In a large, extended population on Snowdon it seemed to be doing well in 2007.

But it may well be down to critically small numbers in Cwm Idwal. How long can this endemic annual survive there?

This is not an

eyebright

Primula scotica

Scots Primrose

An endemic, though part of a difficult subarctic taxonomic complex.

Requires short turf.

Iconic in Scottish conservation

Euphrasia cambrica

Welsh Eyebright

An endemic, though part of a difficult taxonomic complex

Requires short turf

Evidently not iconic in Welsh conservation

Other lines of interest:Other lines of interest:floral biology, a remarkable hybrid and more floral biology, a remarkable hybrid and more

thoughts on Euphrasia vigursiithoughts on Euphrasia vigursii

A typical, large-flowered, outcrossing eyebright.

In freshly opened flowers, the stigma projects beyond the stamens and copious nectar is held at the base of the corolla tube.

(Photo is of E. arctica var. zetlandica)

Floral biologyFloral biology

Opening flower of E. ostenfeldii ssp. rupestris (comb. ined.).The stigma is already curving back into the stamens.

This species lacks nectar.

Floral biologyFloral biology

Lack of nectar is a feature of our smallest-flowered species (E. ostenfeldii, E. cambrica, E. foulaensis), all of which self-fertilise as the flower opens and in which cross-pollination (including hybridisation with other species) is evidently a rare accident.

But another species usually (but not always) lacks nectar …

Apparently a reproductive mimic of Calluna – flowers often match Calluna in colour, aspects of shape and flowering time.

Noted as being pollinated by small wasps, but since plants of the pure species almost always lack nectar, this is an example of deceptive pollination.

A plant of very nutrient poor soils and presumably able to take little from its hosts, so non-production of nectar helps conserve resources.

Euphrasia micrantha

But now another apparent example of reproductive mimicry …

St. Agnes Head, Cornwall, 2007, part of continuing DNA work and looking at variation in E. vigursii – but this was NOT E. vigursii !

St. Agnes Head, Cornwall, 2007

A robust plant, superficially resembling E. vigursii very closely, but with fleshier, glabrous leaves.

Apparently it is E. tetraquetra x vigursii – a diploid-tetraploid cross that has become established as a very vigorous population over a large area.

This population of E. tetraquetra x vigursii seems to be an incipient species, completely replacing E. vigursii in the coastal heathland.

The corollas, or at least the upper lips of the corollas, exactly (to human eyes) match the colour of Erica cinerea flowers, with which it is growing.

Remarkably, for a large-flowered and presumably outcrossing taxon, all examined plants completely lacked nectar.

While it does self-fertilise by continued curvature of the style, it is fairly clearly a reproductive mimic of Erica cinerea.

But has this population evolved reproductive mimicry?

Or has it inherited it from a parent?

E. tetraquetra (in very limited checks) possesses nectar.

Does E. vigursii ?

Copious production of nectar has been noted in other diploids (E. rivularis; E. officinalis subsp. anglica).

[E. officinalis subsp. pratensis (rostkoviana) not yet looked at.]

So far, examination of a limited number of E. vigursii plants in Cornwall & Devon has shown that nectar production is at most very sparse and sometimes seemingly absent.

E. vigursii does itself seem to be a reproductive mimic of Erica cinerea.

Which poses an awkward question …

E. vigursii is regarded as a hybrid derivative of E. officinalis ssp. anglica and E. micrantha and is a quoted example of evolution of an endemic species by hybridisation.

But could this be an example of parallel evolution of corolla colour and habit in similar heathland communities?

Especially as DNA work has NOT so far indicated it is such a hybrid!

BSBI Recorders’ Conference, September 2007BSBI Recorders’ Conference, September 2007

End of presentationEnd of presentation

Documents

BSBI Recorders’ Conference, September 2007 Euphrasia : thoughts on recording and conservation Alan J. Silverside School of Engineering & Science University