Trumpington Meadows 2021 diary

January 1. With Cambridge having been put into covid tier 4 regulations, the normal CNHS start to the year of a group botanical walk couldn’t take place. This meant that Jonathan Shanklin had to make a solitary walk around the CNHS field studies area for 2021 – Trumpington Meadows Country Park. November and most of December had been relatively mild, however the previous week had been much colder, with some night frosts. How would this impact on the number of species in flower?

The day dawned rather bleak and frosty, however the frost had more or less gone by 9:30 and whilst the Met Office suggested some showers, none were forecast to come near Cambridge, although grey skies were expected. The meadows near Byron’s Pool gave a slow start to flowering plants – just White Dead-nettle and Dandelion, but numbers slowly accumulated. The old railway line added a few more, including an unexpected Field Scabious, but then the first unexpected shower fell, dampening the paper recording card. Was it time to head for the shelter of the M11 bridge? By the time I got there the rain had stopped, so I continued round along the M11 to the footbridge, where Greater Periwinkle was in flower. The south-facing motorway bank proved disappointing and the path along the river was muddy thanks to earlier flooding.

Wooden fish at Trumpington Meadows (photo Jonathan Shanklin)

Lunch was taken on a convenient fish (above) and with more rain in the offing the decision was made to cut short the circuit a little and not visit every monad. The concrete spine road didn’t add much, but the adjacent beet field had quite a few arable weeds in flower. Crossing back over the M11 bridge another beet field by the A1309 had another surprise – Corn Marigold in flower. By now there was almost continuous slight drizzle, so a return was definitely a good idea. Passing by the allotments added Annual Meadow Grass, and the final find was a Meadow Buttercup. By now it was raining, which made for a rather damp cycle ride home.

Once all the records were entered the total was 166 plant species recorded, with 50 in flower. This was much higher than expected, and the second highest of all the CNHS walks so far. The mean November and December temperature of 7.1 deg C would initially have suggested a total of around 38 and I had expected fewer given the open nature of Trumpington Meadows. Taking this year into consideration it appears as if the total of 39 in 2016 (Grantchester Meadows) was an outlier as that year had a very warm preceding two months and should have seen well over twice that number. In addition to the plants a few other records were made, including a liverwort, a lichen, a few mosses, 7-spot ladybirds, a brown-lipped banded snail, long-tailed tits and several large mole hills.

May 20. Our first evening meeting took place in conditions more akin to the autumn – cold temperatures and a strong wind. This didn’t deter the dozen members who met up at the appointed place. We started with a walk round a small balancing pond, where we saw some members of the legume family – Common Vetch, Spotted Medick and Black Medick. There were also members of the daisy family – Ox-eye Daisy and Beaked Hawk’s-beard. The half hour that we spent here was not enough for one late arriving member who failed to spot us!

We then walked down the cycleway path, stopping when we found some Creeping Thistle. Jo Garrad, one of the Park Rangers, explained that they were looking for Thistle Rust in order to start a trial on reducing the invasive plant. What they hoped to do was collect spores from infected plants, make this into a solution and spray it onto thistle stems in patches. Trials elsewhere had shown this reduced thistle populations by 80% over a few years.

Continuing on to the large balancing pond we admired the Tufted Duck and other waterfowl that were present. We crossed over to the relict waterside meadow, where we saw the small fronds of Adder’s-tongue and the scrub that had grown up in the last decade. Back on the old railway we saw a few plants of Winter-cress in full flower, but didn’t try tasting any of the leaves. Dusk was now approaching and it was cold, so we walked briskly back to our starting point.

June 2.  We began the visit to Trumpington Meadows at Byrons Pool LNR and started with a look around the meadow.  Jonathan explained that blue Damselflies were difficult to identify as you needed a close look at their markings.  Walking through the meadows he disturbed a greenish one and when it rested again on a grass stem was able to say “I think I can identify this one!”.  It was a female White-legged Damselfly – the first that everyone had ever seen. We continued along the riverside path, where the fish pass now takes so much water that it rarely flows over the weir.  An Ash leaning at 45 degrees across the path suggested that this might be a good spot to avoid in any high wind! Emerging onto Trumpington Meadows we headed towards the Balancing Pond, where Sarah spotted Flowering Rush, although this was probably part of the planting.  Quite a lot of froglets were emerging, so it had clearly been a good year for them.  Perhaps later in the year we will see Grass Snakes!  We had a look along the old railway line, then headed back across the meadows towards Byrons Pool.

July 22. The CNHS group had a lovely sunning evening for their walk round Trumpington Meadows.  We began at the Addenbrookes Road entrance where there is a SUDS feature.  Several new plants had arrived here since our first visit to the site in 2012, including Centaurium erythraea (Common Centaury) and Blackstonia perfoliata (Yellow-wort).  The wetter area had two species of Bulrush and three species of Rush, of which one, Juncus effusus (Soft-rush), had previously been overlooked.

Having circumnavigated the feature we headed down the cycle path towards the motorway bridge. There was plenty of Common Ragwort, but somewhat surprisingly the first Cinnabar Moth caterpillar we came across was on Groundsel and then a couple were spotted on Hoary Ragwort.  We didn’t see any on Common Ragwort, which is their preferred species, and whilst we did see a Six-spot Burnet Moth we didn’t see any of the Cinnabar Moths.  Crossing the bridge, we had a look at the chalk grassland along the margin of the coprolite pit, but this was becoming rather swamped by scrub growth and deposition of mud from the track carefully cleaned by the contract farmer.  Returning across the largely introduced meadow we disturbed several butterflies including Meadow Brown, Marbled White and Gatekeeper.

August 22. With summer coming to an end the CNHS field studies reverted to Sunday afternoons.  The forecast wasn’t good, with heavy showers expected, but only a few drops of rain actually fell.  The CNHS group met at Byron’s Pool car park and began by exploring the Byron’s Pool meadow.  The newly sown wildflower meadow was clearly attractive to butterflies, with Common Blue and Brown Argus amongst others often trying to sun themselves on what was a cool afternoon.  The highlight here was however a Wasp Spider, with the yellow bands more cream coloured than usual.  It captured a cricket whilst we watched, quickly immobilising it and returning to its web.

We then walked along the river, noting that some trees, possibly diseased, were due to be felled.  This however didn’t apply to one Ash that was leaning across the path.  Emerging into Trumpington Meadows Country Park, we spotted one of the plants on the “missing” list – Common Comfrey, near the old railway bridge.  Jonathan tried his hand at fishing out waterweeds from the river using a grapnel, but only came up with Nuttall’s Waterweed.  There were more butterflies by the outfall stream from the Balancing Pond – a nearly pristine Red Admiral and a Peacock.

Moving on to the pond itself, we saw a range of waterfowl making use of it.  Much of the emergent vegetation was planted, but some plants had perhaps come in by themselves.  Grapnel fishing from the observation platform was rather more successful than from the shore, with the former producing Lesser Pondweed and Spiked Water-milfoil, whilst the latter only produced dense swathes of algae.  Dog owners on the far side obviously couldn’t read, as they were encouraging their animals into the pond.

Although we hadn’t travelled far, time was passing, so we headed back towards the starting point.  Along the way we disturbed a few moths in the vegetation, one of which was identifiable as Common Carpet.  We finished with a quick detour to the old pond adjacent to the car park.  Here we saw the blue flowers of Water Forget-me-not and a large orange slug.