Sunday, 2 July 2017

Middle Barton

Another successful recording meeting in SP42 last Sunday (apologies for the delayed write-up). After all those records from TVERC the hectad now looks relatively well recorded, but there were still no recent records from Middle Barton Fen SSSI (SP42N), so recording this site was the goal. With just three attendants we were able to cover ground quickly, getting round the site in good time so as to be able to also fit in a thorough bashing of SP42M.

Initially it didn't look positive that'd we get access to the SSSI so we wandered across nearby improved pasture. We made some surprising finds here on the slope above the fen, the first of which was Filipendula vulgaris (dropwort). There were also several rosettes of Cirsium acaule (dwarf thistle) and clumps of Ononis spinosa (spiny rest-harrow). The best find was Alchemilla filicaulis (hairy lady's-mantle), known at only four sites in the county and not seen at Middle Barton since 1987. After this splendid discovery access was confirmed to the SSSI!

The SSSI along a shallow valley of a small stream is in unfavourable condition, with much of it rank and overgrown with Filipendula ulmaria (meadowsweet). There was a little Dactylorhiza maculata (heath spotted orchid) in this vegetation, but the grazed neutral grassland on the valley slope was in good condition with plenty of nice plants, including Briza media (quaking grass), Dactylorhiza fuchsii (common spotted-orchid), Galium verum (lady's bedstraw), Potentilla erecta (tormentil), Poterium sanguisorba (salad burnet) and Succisa pratensis (devil's-bit scabious).

Another field within the SSSI still supported the distinctive fen meadow community dominated by Juncus subnodulosus (blunt-flowered rush) and Carex acutiformis (lesser pond sedge). Here the vivid green of rush and sedge foliage was splashed with the brighter colours of F. ulmaria and Silene flos-cuculi (ragged robin), as well as a mass of the pale straw-coloured inflorescences of J. subnodulosus. There was also an abundance of the scarce Valeriana dioica (marsh valerian), the un-valerian-like basal leaves forming an understorey to the rushes.

As we'd finished looking round the fen by lunchtime we next headed to SP42M which had only 80-odd post-2000 records. This tetrad supported a decent diversity of habitats, with wooded lanes, road verges, hedges, a churchyard, grassland and small streams with fenny areas, and we found a respectable 193 taxa. This bumped the tetrad comfortably over the 200 mark, including a few near-threatened species such as Knautia arvensis and relatively scarce ones such as Ranunculus fluitans (stream water-crowfoot).

For the next meeting on the 9th July we'll be back in SP42, returning to SP42Z. We were there way back in May and this time we'll be surveying Bestmoor SSSI which holds a large population of the nationally scarce Oenanthe silaifolia (narrow-leaved water-dropwort). Supposedly there are tens of thousands of plants and as well as count these I've been asked to survey the vegetation — I'll therefore be needing lots of help should you be able to spare a Sunday!

Sunday, 25 June 2017

A big thanks to Thames Valley Environmental Records Centre

... and of course to all the botanists who submitted records to TVERC! All 340,000+ of TVERC's plant records for vice county 23 (Oxfordshire) now reside in the BSBI's Distribution Database (DDB), and my word what a difference it makes! The records go as far back as 1794 but most local recorders will want to know how it affects coverage for Atlas 2020 — see below!

The arrival of so many records is a result of a data sharing agreement struck between the records centre and BSBI. In return TVERC receive regular updates of records that come through me as county recorder. BSBI members often wield a more critical eye, recording esoteric taxa such as hybrids, taxonomically critical groups of plants and unusual garden escapees, so perhaps this will improve the coverage of their database. TVERC also get an extra pair of eyes validating their plant records, and this is what I will be doing over the winter, checking all of their hundreds of thousands of records! That's a lot of work but worth it for the great improvement it makes to the BSBI's data holding for Oxfordshire.

Thursday, 15 June 2017

Out Wood SSSI

A botanical meeting was held on Sunday at Out Wood Site of Special Scientific Interest (SSSI), near Kiddington (SP42A). This was a return to square bashing for Atlas 2020 after a previous jolly to Otmoor. The square had a small number of recent records and the plan was to boost this by taking in a mix of habitats including the SSSI and surrounding farmland. The SSSI citation sounded quite tantalising, so I was hoping for some goodies, perhaps even Ornithogalum pyrenaicum (spiked star-of-Bethlehem). The site is in unfavourable status so I wasn't feeling too optimistic

The participants (seven botanists plus a dog) met at Grimsdyke Farm, named after an ancient fortification that runs through part of Out Wood. Along the walk to the wood was a narrow spit of woodland emanating from Out Wood but not part of the SSSI. Here we recorded most of the woodland plants that we would also find in the SSSI, including Allium ursinum (ramsons), Conopodium majus (pignut) and Elymus caninus (bearded couch), and at least one that we didn't, Ranunculus auricomus (goldilocks buttercup). Arriving at the SSSI it was evident that the grassy rides advertised in the SSSI citation were gone: most of the flora was of shade-tolerant clonal species such as Mercurialis perennis (dog's mercury). I'm sure the place had looked lovely earlier in the year given the abundance of fruiting Hyacinthoides non-scripta (bluebell).

We spent a while working the wood, turning up a suite of common ancient woodland plants, including quite a lot of Epipactis helleborine (broad-leaved helleborine) and a few over-done spikes of Orchis mascula (early purple orchid). For the most part the wood was monotonous, and some areas had been planted with Fagus sylvatica (beech) and other forestry trees. However, parts had been deer-fenced to allow coppicing and tree planting and we hoped the increased light, disturbance and exclusion of deer might turn up some plants of interest. We managed to get into the coppice coop containing Grims Ditch but it was a thicket of Rubus fruticosus (bramble). Here we recorded Lithospermum officinale (common gromwell) and the hybrid between Juncus effusus (soft rush) and J. inflexus (hard rush) known as J. x diffusus. We seem to have been the first people to record the latter from Oxon since Druce in the 1890s.

At lunchtime half of the party left and the remainder abandoned Out Wood for a better mix of habitats. Some grassy areas in woods to the east were quite productive with e.g. Hypericum maculatum (imperforate St John's Wort) and Mentha arvensis (corn mint) and what I think might have been Euphrasia arctica (arctic eyebright). The latter is more of a northern/western species with no recent Oxon records. On the route back to the cars was a rather sad hedgerow with a few limestone grassland species hanging on against the assault from intensive cereal farming: here we recorded such delights as Helianthemum nummularium (common rock-rose) and Knautia arvensis (field scabious) and a large quantity of Carex leersii (leers' sedge, syn. C. divulsa subsp. leersii). A bank near the car had a better-preserved limestone grassland flora, and we added Linum catharticum (fair flax) and Ononis repens (restharrow). We also managed to find some good arable weeds with both Kickxia elatine and K. supuria (sharp- and round-leaved fluellens) and Chaenorhinum minus (lesser snapdragon).

Thus while Out Wood SSSI was somewhat undistinguished we gathered a good number of records, 220 taxa in all making the tetrad total up to 231. To be sure there will be more to be found but that's a good start and improves the county's Atlas coverage. Thanks to all who took part!

Sunday, 4 June 2017

Otmoor


The hybrid Viola x ritschliana between the nationally rare and critically endangered fen violet and the locally rare heath dog violet.
Otmoor Site of Special Scientific Interest was the venue for my latest recording meeting, held on bank holiday Monday. The area has been thoroughly botanised over the last few years so the purpose of the meeting was largely to have fun and see one of the finest wet grassland sites in the country, but I had hoped to add a few records. We were joined by members of the Reading and District Natural History Society. I didn't count but with Oxfordshire Flora Group regulars we made up an exceptionally large group (whom I kept waiting for twenty minutes when I mis-remembered the start time!).

I know the Moor well but this was only the second occasion I'd had to access the area around the MoD firing range. There are many wonderful things in there and for these we made a bee-line. As much as I enjoy recording meetings it was refreshing just to be able to walk somewhere with botanists without getting mired in recording all the plants one sees on the way!

Within the range the first species of interest was a weed, which I over-enthusiastically misidentified as the umbellifer Torilis arvensis (spreading hedge-parsley) on account of its hooked fruits. This is an endangered plant, severely declined in Oxon, and everyone got rather excited. Subsequent to the meeting I re-examined the plant and realised that it was instead Anthriscus caucalis (bur chervil), which also has hooked fruits. We all get things wrong sometimes, but this is still an interesting record! While not threatened A. caucalis has very few Oxon records, most of them old.

The author holding Anthriscus caucalis and looking pleased with himself despite being wrong