East of Gravelly Marsh, North Solent NNR, New Forest, Sunday, 10th November 2013

A meeting to look at a stable shingle beach in the morning and acid grassland with coastal scrub in the afternoon in the North Solent NNR within Beaulieu Estate. I had surveyed the west of Gravelly Marsh in the summer of 2012 during a small Hampshire Flora Group meeting. This had a rich coastal heathland with a total of 26 terrestrial and saxicolous lichen taxa were recorded including 16 taxa of Cladonia and two of Cetraria. This gave a reasonably high CCP (Cetraria, Cladonia & Pycnothelia) index score of 18. There was only limited development of strongly maritime shingle communities in the west. Latter that summer during some saltmarsh motoring, however, a brief look at the stabilised shingle vegetation to the east, on the shingle spit leading to Gull Island, suggested that there was an interesting and much more maritime community here.

We met at the shore hide car park at SZ4202 9726, at 10.30 on Warren Lane, with Neil Sanderson leading with Ginnie Copsey, Eric Clement, Mark Jackson, John Norton and Jenny Seawood. As the high tides were currently over topping the narrow neck of the shingle spit we needed to get on to the spit first and get off by mid afternoon to avoid being trapped. So we route marched onto the spit, ignoring the distractions on the way.

The spit is quite recent and is totally absent from the 1870 and 1897 6" OS maps, but with the spit having started to grow by the 1909 OS map. Once on to the shingle we walked along the partly breached narrow neck of the spit. The recently deposited or wave disturbed shingle was bare of any lichens and we headed down until we reached much older old stable shingle (SZ419 969 site 1). The first bits of this habitat were old hooks formerly at the end of the growing spit, possibly dating from about 1909, now pointing into the saltmarsh on the inland side of the spit. These were being over ridden by the recent shingle which was moving inland. The lichen recording, however, started not on the shingle communities but on old bits of wood washed up into the stable shingle as storm debris. There proved to be a lot of this, presumably as the spit is protected as a bird sanctuary most of the year, so the wood is not taken away or tidied up. Recording these logs was to become a theme through the marsh as light relief from recording pebbles. The first log examined supported an abundance of Lecanora zosterae Nb (NS), a coastal specialist lichen, mainly found on wooden post in saltmarshes in Hampshire, but associated more with dead vegetation in the north. Some of this population was parasitised by the fungus Lichenodiplis lecanorae, this is probably a widespread species, but was actually new to Hampshire. Other species on the log were Xanthoria parietina, Amandinea punctata, Melanelixia subaurifera, Physcia tenella, Lecanora conizaeoides f. conizaeoides, Lecanora expallens, Parmelia sulcata, Cladonia ramulosa and Rinodina oleae, A branch nearby added Cliostomum griffithii, possibly as a survival from the original bark assemblage rather than a colonist.

The lower lying shingle supported a transitional community between Atriplex portulacoides Saltmarsh Community (SM14)/Armeria maritimaCerastium diffusum Maritime Therophyte Community (MC5) (Atriplex portulacoidesFestuca rubra vegetation), with the flints supporting a rich lichen assemblage in this zone. It the field we identified Trapelia obtegens, Porpidia tuberculosa, Xanthoria parietina, Candelariella vitellina f. vitellina, Verrucaria nigrescens, Physcia tenella and Lecanora salina Nb (DD/NR). The latter was a good find and proved to be abundant and well developed across the spit on flints. Previously it was only known from the shingle beech at Browndown in Hampshire, where it was first found by John Norton. At this site it was quite distinctive with its thallus of rounded granules showing well. Back in the office species confirmed from flint collections were Catillaria chalybeia var. chalybeia, Lecania erysibe, Caloplaca flavocitrina, Rinodina oleae and Amandinea lecideina Nb (NS). The latter is rare maritime species in Hampshire, best known from Browndown again, but also found in small quality at the western end of Gravelly Marsh in 2012. It was nice to see this much better material in 2013. The lichen has a pale rimulose thallus with pycnidia frequent amount the black disks.

On the highest parts of the spit had some patches of MC5 shingle vegetation free of Atriplex portulacoides and here terricolous Cladonia species had a high cover with Cladonia furcata subsp. furcata, Cetraria aculeata, Cladonia foliacea and Cladonia rangiformis. In contrast the diversity on the flints greatly reduced, with only Rhizocarpon reductum on most pebbles. The Cetraria aculeata was looking a bit “yellowed off” probably from saltwater incursions.

Site 1

The next section of stable shingle was in the same 6 figure grid reference (SZ419 969 site 2). In the Atriplex portulacoidesFestuca rubra vegetation (SM14/MC5) a similar assemblage occurred on the flints, with the Lecanora salina Nb (DD/NR) even finer and here supporting the fungal parasite Lichenodiplis lecanorae [NS], The latter was also noted on Candelariella vitellina f. vitellina. The Lecanora salina was even growing on the stems of the Atriplex portulacoides and a search was made of this unusual habitat for lichens, which added Xanthoria parietina, Candelariella vitellina f. vitellina, Lecanora zosterae and Xanthoria aureola, the latter a rare costal species in Hampshire, also on flint here. Finally a sorediate Caloplaca sp, with yellow punctiform sorelia arising from grey areoles, was collected from a Atriplex portulacoides stem. This was eventually identified as Caloplaca sorediella Nb (NR) (see paper), which has been recorded rarely from the west coast on rock and on the base of plants, e.g. Thrift Armeria or Spergularia. This record was the first from the south coast east of the Lizard, so a very good record. An odd looking Rhizocarpon sp on flint, proved to just be Rhizocarpon reductum, while Rinodina oleae and Catillaria chalybeia var. chalybeia were confirmed on collected flints latter.

Site 2: scan of Lecanora salina

Moving east we entered a new grid square (SZ420 970, Site 3) and a large area of stable single. In Atriplex portulacoides Festuca rubra vegetation (SM14/MC5) Caloplaca maritima Nb (NS) was found on flint. This is another rare maritime lichen in Hampshire, although old records of more strongly maritime deep orange Caloplaca marina from the county are probably actually of Caloplaca maritima. The latter is golden-yellow and is is found higher up the shore but was only relatively recently separated from Caloplaca marina. Oddly Lecanora zosterae, Candelariella vitellina f. vitellina and Xanthoria parietina were found growing directly on stable mud in this community.

Here there was much more higher ground with Maritime Therophyte Community (MC5) and we concentrated in recording this community. There were strongly developed Cladonia mats with Cladonia furcata subsp. furcata, Cladonia rangiformis, Cladonia foliacea, Cetraria aculeata, Cladonia floerkeana, Cladonia rangiformis, Diploschistes muscorum on Cladonia furcata subsp. furcata, Parmelia sulcata, Hypogymnia physodes, Ramalina farinacea, Evernia prunastri, Punctelia subrudecta s. str. and Agonimia tristicula. The associated vascular plant flora was clearly rich, but as the spit is off limits in the bird breeding season so may not be well recorded. We noted Sea Holly Eryngium maritimum, Restharrow Ononis repens, Sea Bindweed Calystegia soldanella and Sea Sandwort Honkenya peploides. John Norton collected a fungi from the dead remains of the latter which a was identified by Howard Matcham as Pleospora herbarum. Howard Matcham stated that “according to the literature the ‘most common’ plurivorous ascomycete on herbaceous species” but that he had only seen it once in west Sussex and this was the second record from South Hampshire.

Within the MC5 in Site 3, the flint lichen assemblage was richer than in MC5 in Site 1, but different from the SM14/MC5 assemblage. Lichens noted were Porpidia soredizodes, Buellia ocellata, Xanthoria calcicola, Caloplaca flavocitrina, Rhizocarpon reductum, Candelariella vitellina f. vitellina, Melanelixia glabratula, Physcia adscendens and Parmelia sulcata recorded. A pebble of eroded unknown soft calcareous material added Toninia aromatica.

Further washed up logs were recorded with lichens noted being Lecanora expallens, Parmelia sulcata, Flavoparmelia caperata, Lecanora chlarotera, Rinodina oleae, Physcia tenella, Trapeliopsis granulosa, Placynthiella icmalea, Cladonia rangiformis, Melanelixia subaurifera, Cladonia humilis, Hypogymnia physodes, Amandinea punctata, Evernia prunastri, Punctelia subrudecta s. str., Physcia adscendens, Lecanora symmicta, Lecanora barkmaniana Nb (NS), Lecanora zosterae Nb (NS), Illosporiopsis christiansenii [NS] on both Physcia tenella and Candelariella reflexa, Xanthoria candelaria s. lat., Lecanora confusa and Lecanora hagenii.

Site 3: lichen rich MC5 vegetation & stranded log

In the MC5 vegetation another lichen substrate found was old sea shells, mainly cockles but also winkles about SZ4209 9702. These are one of the few natural hard calcareous substrates in Hampshire. I had hopped that a Caloplaca on a cockle was something interesting, but it was just Caloplaca oasis the common C. holocarpa segregate. Other species on cockles were Sarcogyne regularis, Lecanora albescens, Rinodina oleae, Xanthoria parietina, Verrucaria baldensis and Verrucaria muralis. On a winkle shell Verrucaria nigrescens and Lecania inundata (NS) were recorded, the latter new to Hampshire. The Lecania inundata is probably a common species that has been over looked for Lecania erysibe, however, Lecania inundata lacks the blastidia (a rounded, lichen corticate propagule produced by budding of a thallus) found on the thallus of L. erysibe.

Site 3: lichens on cockle shells

As time was pressing I then crossed over to the inland side of the spit and walked down into the saltmarsh to see if I could find any stable mud free flints low down in the marsh. This is a habitat, which has produced interesting maritime Verrucaria species in the past in the Solent, but here the few low lying pebbles were too muddy. The deepest peddles with lichens supported Lecanora salina Nb (NS) and Rinodina oleae.

Walking back over a wide area of Atriplex portulacoidesFestuca rubra vegetation (SM14/MC5), there were mats of the local coastal moss Tortella flavovirens, with the lichens Lecanora zosterae and Xanthoria aureola. At SZ4203 9602 I was stopped in my tracks by the distinctive apothecia of a Caloplaca cerina group species apparently growing on a sorediate greenish thallus on top of Tortella flavovirens mats. This really stumped me, the only terricolous Caloplaca cerina group species recorded from Britain, Caloplaca stillicidiorum, is a upland limestone species. Searching around occasional further apothecia were found on debris and humus on the ground and on the stems of Atriplex portulacoides. On the latter the connection with the greenish thallus became clear and it was obvious that the thallus was abundant in this area, but only rarely supported apothecia. There was not time to record the associated species but Lecanora zosterae Nb (NS) was noted on Atriplex portulacoides.

Caloplaca sterilis? on Tortella flavovirens.

After some wild guesses in the field, back in the office I consulted Šoun et al. (2011) and had a good look at the collected specimen. The thallus was green when wet but became grey-green when dry and consisted of small squamules 0.05 – 0.25 mm across, with soralia developing on the edges. The soredia remaining green as the specimen dried. The few apothecia collected ranged from 0.25 – 0.35 mm diameter and the disks were orange with priuna on the surface darkening the colour. I only sectioned one apothecia, as there were only a few. The epihymenium was orange and K + purple, the rest of the hymenium and the hypothecium were hyaline. There were few free spores but 10 measurements were made.

Gravelly Marsh sample:

Spores: 11 – 15 (–16) x 7 – 9 (–10), septum 4 – 6 (–7) µm wide (n = 10)
Asci: 33 – 39 x 14 – 17 µm (n = 10)

Running through Šoun et al. (2011), there was one obvious match; Caloplaca sterilis. Described as a new species in the paper, this had a very similar thallus, although the squamules of Caloplaca sterilis are often white pruinose but can be just grey-green and the apothecia are only sometimes pruinose, otherwise it matched well externally. Internally the spores were within the range of Caloplaca sterilis but averaged a bit larger and the asci matched reasonably well. This was quite a surprise as Caloplaca sterilis was not only not recorded from Britain, the confirmed records in Šoun et al. (2011) are from steppe landscapes and in coastal habitats on sand dunes in SE Europe. Here is grows on the basal parts of woody plant stems (Artemisia, Halocnemum, Thymus), plant debris and dead wood. So the habitat at Gravelly Marsh was not that different. Also Šoun et al. (2011) mention two old specimens from old palings from Cherry Hinton near Cambridge collected by Larbalestier in 1879, which seem to be identical to Caloplaca sterilis. They considered, however, that molecular data was needed to confirm the identity of British material.

Spore & Asci measurements from Šoun et al. (2011) for SE European material (converted to whole numbers):

Spores: 8 – 12 (–16) × 7 – 9 (–11) µm, septum (2–) 4 – 6 (–7) µm wide (n = 32)
Asci: (33–) 37 – 44 (–46) × (10–) 11 – 16 (–20) µm (n = 20)

I have posted the specimen to Jaroslav Šoun for comment.

We had now spent most of the afternoon on the spit and it was time to get off well before the rising tide was an issue, so we route marched off the spit to the eastern shore of Gravelly Marsh. Just off the spit (Site 4, SZ416 968), the waxcap Hygocybe ceracea was noted in grassland along with the lichens Peltigera canina along with Cladonia furcata subsp. furcata along with Burnet Rose Rosa pimpinellifolia. There were some Oaks trees and a few Blackthorns and Hawthorns which were recorded but did not support any significant lichen interest (see species list). On passing Bearded Tits were heard in the reeds by John.

To the north east (Site 5, SZ418 970) the parched acid grassland supported a more varied lichen assemblage with:

Cladonia ciliata var. ciliata
Cladonia cryptochlorophaea (NS)
Cladonia furcata subsp. furcata
Cladonia portentosa
Cladonia ramulosa
Cladonia rangiformis
Peltigera hymenina

Further trees added Ramalina canariensis (a UV – form, but with the hollow branches confirming it), Anisomeridium biforme and Arthonia radiata and by the road an old boundary Oak had a large colony of Parmotrema reticulatum and Cladonia coniocraea was recorded on a fence post.

We recorded a total of 75 taxa, of which 31 where only found on trees or wood (with 19 on the logs on the beach) and 44 were found in the shingle habitats (see species list). The shingle heath at Gravelly Marsh recorded in 2012 included another 15 taxa not seen to the east in 2013, giving a total of 59 species from the shingle habitats. This is a high number for this sort of habitat in Hampshire, and included some significant records, including a potential new species to Britain, Caloplaca sterilis, which is yet to be confirmed, and the first record of Caloplaca sorediella Nb (NR) for the south coast, east of The Lizard. The populations of Lecanora salina Nb (DD/NR) were particularly spectacular and could be the largest known in the country. This is certainly the richest maritime shingle community known in Hampshire, but also indicates the need for further surveys of the resource in the Solent.

I forgot my GPS, so the of the route Google Earth below is reconstructed from memory and GPS readings from my phone, click on link below.