Ignoring, no, deleting the spam comment thoughtfully sidelined by WordPress on a “Practical Pregnancy Plan” as I logged in today, this is a post with a few unanswered “Why’s”?
A simple question I always dreaded hearing from a client. Demanding of an explanation, when often none was rationally to hand. I tended to flip it, and say in certain situations “Why” wasn’t the right question to ask. Or if it was, then I was incapable of producing a meaningful answer.
The need to understand is rooted deep in many of us.
Life’s wider tapestry is surely interwoven with many occasions, when we yearn to know “Why?”
Certainly all valid.
But then move on, perhaps enriched, perhaps having learned a valuable lesson. Perhaps now better prepared for the next curve ball lobbed in our direction.
But probably not.
The garden and landscape seem full of such questions just now.
With the extended heat wave persisting and our water supply reducing, it was a make or break weekend for some of our shrubs and trees. It’s been very interesting to discover different drought tolerances in those plants which have been in the ground for several years. (Delays in finishing this post means that significant rain has finally fallen!)
We simply haven’t had enough water, fresh or salvaged to save everything that’s seriously water stressed. Many of our favourite Himalayan or Asian origin plants which thrive in our constant high moisture environment are close to failing. Having recently discovered the wonderful Met Office rain radar site, click here, why has rain recently fallen all around us, yet a small area centred around Mynydd Llanllwni stayed so dry? My suspicion is that a huge mountain, devoid of any surface moisture, heats up significantly under weeks of sunshine and the thermal mass and retained absorbed energy is sufficient to affect moisture laden clouds heading our way.
Strangely many evergreen Skimmias and mature Daphne bholuas seem very drought tolerant, yet Leucothoes are only just hanging on.Why the difference? Is it improved water uptake, or reduced water transpiration? Or both? Who knows?
With little water available at root level, most plants have struggled to flower well, or sustain flowers for any length of time. The impact for many invertebrates on availability of pollen and nectar must be significant, so it was a delight that a visit by Clare Flynn from Bumblebee Conservation Trust (BCT) to survey our bumblebees was so successful.
She managed to find many bumblebees, of 7 different species, including a Cuckoo bumblebee, Bombus vestalis, which I’d never seen before (above), and Clare was particularly pleased to confirm this, once she’d temporarily popped into a pot to examine more closely.Convinced by the day’s results that we do have vibrant bumblebee populations here, I felt I should try to record these insects in a more meaningful way and so have set up a transect walk using BCT’s Beewalk programme. Click here.
This is an impressive attempt by the charity to get amateur observers involved. However, the site loads really slowly on our sluggish satellite internet, and after spending over an hour inputting data from my first walk (actually taking longer than doing the walk), I was aghast to see that after clicking the “save” data button a page popped up telling me that for an unfathomable reason my data hadn’t been saved and was indeed lost.
I shall resort now to a simple home designed spreadsheet (thanks to Fiona) which will be quicker and hopefully more resilient, if not as shareable. However, the very helpful staff at BCT have now offered to input my data if I can get it to them on such an Excel based spreadsheet. Well done indeed to them.My initial walk around the garden and 2 of our meadows, of about 1300 metres length, and recorded in bee walk fashion – noting any bees seen 2 metres either side of the route, and 4 metres ahead – recorded 101 bumblebees and 6 honeybees.
What will be very interesting to monitor, if I can manage to repeat this often enough, is the range of flowers the bees visit through the year. In part, this obviously reflects the number of available flowers in the garden and meadows at a particular time, and which are close to my route, but is also obviously influenced by the bees’ preferences.
An initial glance at my figures suggests that over 60 % of the bees on this first walk were found on just 3 flower species – Common knapweed, Centaurea nigra, Marjoram, Origanum vulgare, and Greater Birds-foot-trefoil, Lotus pedunculatus. All native species in peak flower during the last week of July.
Buddleja and Stachys officinalis flowers accounted for another 15% of their flower visits.
So, a very narrow selection given all the different flowers still available in the garden and meadows. I wonder to what extent these are the species in this year of extreme drought conditions which have coped best and continued to flower well, and still produce a good nectar and pollen resource for the bees?
The Trefoil flowers are growing in our wet meadow and so haven’t been as affected by water shortage, but the Knapweed, Marjoram and Buddleja certainly seem to have coped better than many other plants in very poor dry soils.
A recent piece of research attempted to assess the impact of (artificially created) drought on flower and nectar production. Droughts are widely expected to become more common even in temperate regions as a result of climate “change”. Click here for a very readable and interesting study paper,
Drought reduces floral resources for pollinators
by Phillips,Shaw,Holland, Fry, Bardgett, Bullock and Osbourne
Using trials based on common calcareous grassland species in the UK, an ecosystem type which is naturally held to be quite drought resistant anyway, they found that flower abundance, flowers actually containing any nectar, and nectar quantity per flower, were all reduced significantly by drought conditions. Clearly this would likely impact on pollinator behaviour, and populations as well.
I just hope they’re still here! The second day after they arrived, lots of honeybees were obvious around the garden, collecting pollen, but 5 days later a very hot day saw a lot of bee “milling-around” activity outside the hive, and now there seem far fewer bees entering and leaving. Might some of them have swarmed? Tony will fill me in on his next visit to check them. (They are still there!) I love to see honeybees working in the garden, but have long felt that I simply don’t have time to manage a hive, so Tony’s offer to place a hive on site and manage it was too good to decline.
The Welsh fifteen moment arrived very early this year, when I found over 15 butterflies on our Buddleja bushes. Within 24 hours, there must have been nearer a hundred – mainly Peacocks, Aglais io, a few Painted ladies, Vanessa cardui, and a few Red admirals, Vanessa atalanta. A Small copper, Lycaena phlaeas, joined the party, then a Comma, Polygonia c-album, and finally a fleeting glimpse on 2 occasions of a large orange and brown/black butterfly. A male Silver-washed Fritillary, Argynnis paphia, no doubt brought into the garden by the scent of the Buddleja (bottom right, below).I’ve only ever seen one once before in a glade in the nearby Brechfa Forest, so this was a real treat. A Hummingbird hawk-moth, Macroglossum stellatarum, and 3 significant Dragonfly species – Golden-ringed, Cordulegaster boltonii, Emperor, Anax imperator, and Southern hawker, Aeshna cyanea, resting on garden plants created a surfeit of photo opportunities, even though the majestic male Emperor dragonfly looked like he’d had several close shaves with chunks taken from those delicate wings.
Not to be outdone the Lysimachia clethroides – another wonderful insect friendly flower for many flies and butterflies, yet a plant which had to be given water to prevent its collapse this week, caught my eye as a very large bodied furry black fly carefully worked its way around the tiny white flowers on the bending goose-necked inflorescence.
Tachina grossa is one of the largest flies in Europe, and as with many oddities it turns out that whilst the adult is strictly vegetarian, feeding off nectar or pollen, the lifecycle involves the fly finding the caterpillars of large moths – Eggars, Lappets, some Hawk moths and the Fox Moth, which certainly is locally common – to lay its eggs on. The fly’s larva then eats the caterpillar. Click here for more on Tachina grossa in the UK.
Finally I found this Ichneumon wasp ovipositing beneath a Common knapweed, Centaurea nigra, flower. There are over 24,000 species of these parasitoid wasps which have been described around the world. Many more are thought to exist, and whilst the adults feed on nectar and pollen, their larvae parasitise other invertebrates like aphids, moths, flies and butterflies, and are significant controlling influences on the over expansion of such prey species.
The modified sting/ovipositor can be very long indeed, and although of considerable length, is controlled with great accuracy by the female wasp, with it often being guided into place by tapping of the wasp’s antennae to locate a cavity in the plant tissue, as in this case, which indicates the presence of the target larva beneath the surface.
The hypodermic like ovipositor (which lies protected within the wider sheath, when not in use) is capable of delivering an egg from the female, followed by venom, either adjacent to, or directly into the target larva, and on emergence the ichneumonid larva then begins to eat the host, eventually reaching maturity and pupating, before emerging from the now dead host, as an adult wasp.
This wasp is of a very small scale, as can be seen by comparison with a Bombus pascuorum, bumblebee worker. Readers may recall that back in 2013, I managed to photograph the largest European ichneumon wasp ovipositing on a log outside our back door. Click here for more on this.
I posted this piece recently for the Carmarthenshire Meadows Group (CMG) and am including it here for any readers who might might be interested.
For any meadow owners who’ve had to cut a crop for hay or haylage, it’s clearly been the best year in ages for getting it into a shed or wrapped with no problems, though perhaps quantities are reduced after the cold late spring and then very dry weather from May onwards.
But for anyone who has stock that are grazing their land permanently, there are currently likely to be huge issues with the lack of aftermath regrowth. Our total annual rainfall here, since I began measuring it, has ranged from 1600 to 2150 mm. Monthly maximas from 534 mm in December 2015 downwards. Our previous longest summer dry spell saw 95 mm fall in June and July of August 2014. This year we have had just 89 mm since May 1st.
So I’m sharing some of our experiences this year. We only take a hay crop off part of 2 (out of 6) paddocks – 1 upland sloping, 1 valley bottom wet, which we need for our small flock of Tor Ddu sheep. We do this semi-manually, by cutting with a walk behind BCS Powerscythe, turning mainly now with a mini Molon turner which fits onto the BCS power unit, which also rows the hay up. Although under some conditions manual turning works better.
The hay is then raked and manually stuffed into big bags and dragged off the fields and stored loose in small hay sheds. We’ve found it stores better out of the bags. The manual effort involved in this means, as old fogies, we can never cut more than a small amount in 1 day, since we have to be prepared to make hay in 48 hours, which has been the default maximum time between showers for many recent summers until this summer of 2018.
After experimenting for 5 years, this year we decided to start cutting the peripheral field margins on our upper hay meadow first since this always grow lusher and quicker than the central areas of this field. This began on May 21st. Stock had been kept out from early February. The crop was very light, but conditions were good for haymaking, though some overheated and needed manually re-turning (below) once the typical showers, which weren’t on the forecasts, had been and gone.
Interestingly, the very early first cut areas behaved as though they’d had a Chelsea chop (in gardening parlance). Since the annual Yellow rattle, Rhinanthus minor, was beheaded before any seed was set, it regrew, flowered and set seed after the main crop in the centre of the field had finished – a great extra resource for nectar seeking insects..
Although the masses of Sweet vernal grass, Anthoxanthum odoratum, which is our primary grass species in the upper meadow, had flowered in the early cut sections, it hadn’t set seed. However, this grass species hasn’t produced much of a second flush of flowers. Instead, the later flowering grasses, (including Common bent, Agrostis capillaris, – though I’m not a grass expert!) have now produced seed heads.Even more surprising was that in one area subjected to an early cut, a single Heath Spotted-orchid, Dactylorhiza maculata, hybrid, survived, flowered and set seed, in spite of such an early assault. The later flowering Greater Bird’s-foot-trefoil, Lotus pedunculatus, has also recovered and is just now producing some flowers and greenery in areas near to the hedges, in spite of the drought.
How do other areas of this meadow look now? Some small sections with the majority of the increasing orchid count.(83 this year, up from just 1 flower, 4 years ago) are still uncut and now straw like in appearance.
The main section of this field cut in late June, (above middle left), and on an East facing slope have almost no grass regrowth at all. But there’s still greenery in this section – the Ribwort plantain, Plantago lanceolata. Dandelions, Taraxacum spp. and Fox-and-cubs, Pilosella aurantiaca.
All with deeper root systems looked slightly stunted but still green. The sorrel, Rumex acetosa, is just beginning to recover too, in this late cut area.Whilst in the earlier cut sections the closely related Sheep’s sorrel, Rumex acetosella, has flowered and set seed.
At some point we’ll need to wean our lambs onto this field, so even with our low stocking density we do need some aftermath grazing. Shifting these meadows towards greater diversity, and cutting early (at least some sections) will definitely have helped overall productivity in the very dry conditions of 2018. In addition, it may have really helped all the invertebrate life which would been more impacted with conventional removal of all the crop at one time.
Obviously, however, this piece-meal approach won’t easily work with larger machinery or with a contractor, but for any with smaller areas, say less than 2 acres, it could be an option to consider.
With the above backdrop I was interested by the recently established trial on increasing diversity in pasture swards by the University of Reading. The Diverse Forages project began in 2017. By using standardised plots using increasing numbers of species in the seed mixes for newly sown pasture (6,12,17 species), it has a number of targets and measurements:
• Biomass yield, forage quality, botanical composition, and soil properties in a long-term replicated trial plot study at multiple sites
• A comparison of pasture resilience under waterlogged and drought conditions assessed using trial plots
• On-farm case studies from ten demonstration farms in South and South West England
• A two-year evaluation of forage nutritional value, including measurements of digestibility, nitrogen use efficiency, methane emission mitigation potential, and growth rate of grazing cattle
• A modelling exercise to determine economic and environmental impacts of the mixtures at farm-scale.
You can read a review of a discussion workshop of its first year’s results by clicking here.
This review includes:
“Results from the EU Cost study showed that 98% of the mixed swards tested outperformed the yield of the average component species
sown in monoculture,”
and “The SmartGrass project indicated reduced requirement for
worming lambs fed on multi-species pasture.”
and “described how one dairy farmer growing diverse forages had enabled him to more than double his soil organic matter over a number of years which in turn allowed him
to increase stocking rate.”
Click here for more detail on the study which will run for 5 years. Although it’s clearly aimed much more at commercial farmers, than a typical CMG member, it may raise awareness of the benefits of sward diversity, and after the 2018 results are available, it may indeed highlight the fact that in extreme weather, having all your fodder eggs in the perennial ryegrass basket is a very dangerous thing to do.
Most readers on this site will of course already be aware of the huge benefits of species diversity in grassland – that’s partly really why CMG exists, but it’s great to see that some hard data on species diversity in pasture may gradually be accumulated and affect mainstream agricultural practice, once a study like this has been completed.
Reinventing the wheel perhaps?
The National Botanic Garden of Wales (NBGW) held a special pollinator weekend very recently, and I nipped down to try to catch Lucy Witter’s talk about her Phd research on creating annual flower meadows for pollinators. Clouds were building form the North West as I left the parked car, and I ended up walking back and grabbing an umbrella. Just in case.
As I reached the double walled garden, and a vista of annual floral “meadow” flowers between the walls, the first flashes of lightning struck so I dashed to some shelter beneath the canopy of the butterfly house, as the rain fell more heavily. As thunder rumbled all round, the intensity of the storm grew, and for about 3 minutes it felt like I was witnessing a tropical storm as torrential rain lashed down, and palm trees behind the clumps of Agapanthus were doubled over.
The initial phase of her trial has been to grow 4 different, commercially produced mixes of annual flowers on 16 square metre plots replicated 5 times, in 2 different locations. The seed was sown onto rotovated ground which had been raked over, in late March to April. To achieve even coverage, the seed was mixed with horticultural fine sand to ease uniformity of sowing and then hand scattered, trodden in, left uncovered, and not watered artificially.The plots seem to have had very good and even germination, but inevitably hand weeding of the plots was required early on, and Lucy has since then recorded the species of bees (bumble and solitary, as well as hover flies) at monthly intervals, which have visited the different flowers as they have opened. In addition, bees have been sampled for pollen to discover which other flowers they might have visited.
Lucy’s long term aim is to continue the trial next year with her own selection of plant species, and ultimately to prepare mixes of seeds of suitable plants which can be grown in this way successfully by gardeners both in Wales and further afield.
Lucy will have much more information to pass on in the years ahead, so it’s well worth looking out for her blog updates or further presentations. Many thanks for her continuing with the event in spite of the weather!
Click here for more on Lucy’s work at the NBGW.
I drove home through continuous heavy rain to find the gauge at Gelli Uchaf nearly empty. The showers had passed South. Fortunately the weekend saw our fortunes change and significant rainfall.
Yesterday, as we were confined to the house for much of the day by steady rain, exchanging stories with my visiting brother and wife about childhood memories, Australian poisonous snakes, and how they impact on rural gardening there, Fiona noticed a sudden gathering of what looked like swallows on a hazel tree beyond out terrace garden. Perhaps 40 or 50 clung to the upper branches of the tree, both Swallows, Hirundo rustica, and House Martins, Delichon urbicum, as quite heavy rain fell.
This is a really unusual sight here – sometimes swallows gather on our phone wires in moderate numbers, but I can’t recall ever seeing so many grouped low down, hirundine cousins intermingled, rain bouncing down on black and white backs and rusty bibs.
Long tails and stubbier ones occasionally in view as they took off and landed, taking the place of the unseasonably early shed leaves on the upper twiggy branches. What had brought them in so low, and why had this “flight” paused in the rain to gather on the hazel? Apparently the 2 species will occasionally interbreed, and usually feed within 450 metres of their nesting site. For some reason the martins never seem to nest beneath our eaves, instead preferring our neighbour’s property. On the basis of this gathering, it seems to have been a successful breeding season so far.
We’d headed for the water’s edge.
Leaving the beached, bleached bodies and camera behind, the stretching sands took us to estuary’s mouth. The tide had just turned, and was rushing back, so quickly we savoured the empty expanse of fixed, rippled sands, bleeding into Western seas. And the calm, horizon sky.
We returned through dunes, deserted.
The colour had mainly gone. But here and there tall, fading, twisted orange flowers of fragrant evening primrose had caught the intensity of the recent heat in their day’s blooming; a single plant with tiny flowered closing storksbills prepared to fling its few dry augured seeds to drill down and colonise across the naked sand; bumbles found the clumps of unidentified flowers of mauve and blue, and gorged.
We bent and found our own nectar – the scent of ripened pods of bee orchids, erect, yet dessicated; stiff brown; burned vanilla filled our nostrils, with eyes closed.
Moving on, a climb past splitting boar and greening poems to find the still standing roundhouse in a special grove; then, later, vodka fuelled Siberian composition erupted from the glossy black grand, beneath the modern oak arches. A lost friend’s elegy re-imagined with English fingers, on a German piano in a Welsh, evening landscape.
Modest’s glorious pictures, listened to with rapture.
Doubts were cast away.
A take on “Why”. Which I’ve always enjoyed listening to.
But only now heard.