Thursday, 8 February 2018

The year in botany

Recording plants at Somerton during a field meeting in May 2017
Now that we're well into the new year I thought it about time I had a look back at 2017. Much more happened during 2017 than can be summarised here — you can get an idea of local activities during the last year by reading the blog posts. If you've any highlights you'd like to share then consider leaving a comment below this post. It was a memorable year for me, not least as it was my first full year in the post of vice county recorder. I have enjoyed beginning to get to know the county's flora and its botanists, particularly through meetings (ten of which were covered on the blog). Numerous local botanists have also been out enjoying themselves outside of meetings, and it has been a pleasure receiving their records and learning what they've been up to. It has been particularly gratifying to see new recorders find their feet (there was a beginner recorders' meeting in April), and for me to be in a position to assemble everyone's contribution to Atlas 2020.

So far 13,623 records made during 2017 have been submitted to the BSBI Distribution Database (DDb). A further 4,114 records were submitted to iRecord, but these have yet to migrate over to DDb. iRecord submissions were almost double that of last year due to new recorders taking up this platform, but 13,623 is a bit of a dip for the DDb compared with 2015 and 2016 when over 24,000 and 25,000 were submitted, respectively. If you have records please therefore send them to me! I blogged earlier in the year about the the vascular plant record sharing agreement with Thames Valley Environmental Record Centre (TVERC), which was quite a big development, making a huge difference to the BSBI's Oxon data holding, with over 340,000 records received. Many recorders over the last couple of decades have preferred to send their records to TVERC, and being able to tap this activity has made a significant contribution toward Atlas 2020. It has been and continues to be a big job to check all these records but it is worth the effort!

I'm sure you're desperate to read how the county is getting on with Atlas 2020 following the 2017 recording season — the up-to-date tetrad (2km square) progress is shown in the map to the left, based on DDb records from the beginning of 2000 to present. This shows more clearly than maps I've previously published how survey effort has been expended, with both tetrad total taxa (tetrad colour) and total recording rate (tetrad size) illustrated. While coverage of the county has continued to improve, one can see that there is work to do in terms of consolidating the recording done to date, i.e. increasing the cover of 'bigger squares' (generally a recording rate of 60% requires about 200 taxa to have been recorded), and recording in the far-flung areas around the county boundary. This is essentially the message I've communicated previously, such as on the Atlas 2020 page, so we just need to keep on working at this up to the conclusion of the Atlas recording period.

The Oxford and Otmoor areas (SP50 and SP51) exemplify the situation we would ideally like to reach but as I've said before it is not essential or possible to fill every gap. At the scale of hectads (10km square), which will be the mapped units in the published Atlas 2020, most now stand at 50-60% recording rate or better (and similarly for the re-find rate), and most have at least 20% of tetrads with 100 or more taxa recorded, which is quite a good situation; targeted recording during 2018 and 2019, including repeat visits to tetrads, will improve the recording rate. Please do get in touch if you need help identifying areas for recording in your area.

Tetrad coverage for Atlas 2020, with tetrads coloured by number of taxa recorded since 2000, and square size scaled by total recording rate, i.e. the proportion of taxa recorded since 2000 out of all taxa recorded.

Above: Potamogeton nodosus in the Thames, Frank Hunt. Right: Carex muricata subsp. muricata in the Chilterns, Geoff Toone.
Now I come onto the less dry developments of 2017, the records of notable plants. The record that stands out of course is Frank Hunt's rediscovery of Potamogeton nodosus (Loddon pondweed) in the Oxfordshire part of the River Thames, a nationally rare species which had only ever been known in the county for a short period during the 1940s. Its reappearance in the Thames it turned out had actually already been established on the Berks and Bucks reaches of the river by the Environment Agency a few years ago, but this was still a very exciting record for Oxon. This rediscovery follows that of Rosa agrestis (small-leaved sweet-briar) in the county in 2016 — I hope that we may have a rediscovery every year!

Recording meetings during the year turned up many records of note. Less satisfactory was the grotty umbellifer found growing submerged in the River Cherwell during the meeting in Somerton in May: it was suspected to be Oenanthe fluviatile (river water-dropwort), thought extinct in the county, but later searching could not relocate it and its identity remains a mystery. On the same meeting was re-found a small population of the uncommon crowd-pleaser Saxifraga granulata (meadow saxifrage), a larger population of which was also rediscovered in December at Peppard chuchyard on the New Year Plant Hunt. With the county generally quite under-recorded, there are plenty of opportunities such as these for re-finding notable plants at old localities as part of Atlas recording, e.g. Fay Banks' Sambucus ebulus (daneberry) at Garsington this last year. Recording also turns up unusual or casual plants, and this year I had an odd weekend when several records of the locally rare Anthriscus caucalis (bur chervil) were sent to me.

Finally, a little-known Oxfordshire plant, the nationally rare Carex muricata subsp. muricata (large-fruited prickly sedge), came to my attention this year when I received a batch of records from Geoff Toone and Paul Stanley from back in 2011. Only discovered in the county early in the 2000s (I think at Hartslock, though I can't find the record), this sedge is beginning to emerge as potentially quite a widespread plant of Chiltern beechwoods, and many thanks are due to Paul, Geoff and others for continuing to track it down.

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