Tuesday, March 30, 2021

Bluebell,daffodil & bee

 On the first really pleasant day of the year (21 degrees), I sat for some time in the Green Sanctuary and, as has been the case on this date sometimes in the past, it seemed unusually quiet.  There were however brimstone butterflies and bee flies enjoying the sunshine.  I keep thinking the garass is not growing as vigorously as it should and there are large areas of 'meadow' in the garden and M3 that are covered in moss, although bulbous plants such as daffodils, bluebells and colchicums seem to be growing more strongly than usual.  I haven't seen an worm casts in M3 whereas 16 years ago they were a fairly obvious feature.

Under the medlar tree I have discovered a bluebell.  Quite a large size so it must have been there for a year or two and an interesting addition to the plant list as it is associated with ancient woodland.

The small sallow bees, Andrena praecox, are about again.  They only sit very briefly on the birch trunk, but I caught the one below on a Tenby daffodil just behind the place I sit to study M3.

Wednesday, March 24, 2021

Trees and flies

 The picture below is taken from where I usually sit looking across the Green Sanctuary towards the north east.  Within this picture which covers an area about a square meter in extent, and including part of the original Square Metre, the following tree species, 12 in all, are growing, self-sown by wind, birds or animals: birch, oak, wild service, goat willow, holly, hornbeam, ash, hazel, hawthorn, wild privet, yew and sycamore.  There are two species of wild rose, ivy, bramble and spindle that has suckered in from the side.  There is a planted hedge of box and Lawson's cypress at the rear.

It is difficult to see all these species in the picture and I keep most of them reasonably small so that they don't take over.  However, it does show how woodland can regenerate from open grassland if nature is left alone to do the job for herself.

The mature birch tree towards the left is now regularly shedding storm blown unopened male catkins.

The sallow flies, Egle spp., that breed in sallow catkins have emerged.  The one below is settled on a dead oak leaf speckled with a microfungus that will eventually help with its breakdown and return to the earth.

Sunday, March 14, 2021

Cercospora leaf spot

Today I noticed that some leaves on the wild privet (Ligustrum vulgare) that grows, bird sown, in the north west corner of The Green Sanctuary had several leaves with brown ends.  The brown, dead part was differentiated from the rest of the leaf by a purplish semi circle and, on closer examination indoors, many spore-bearing pustules were seen on this band and across the rest of the underside of the leaf.

This is caused by cercospora leaf spot (Thedgonia ligustrina).  It is, I am sure, is quite common wherever privet grows in the British Isles, though it is rather seldom recorded. It does not appear to cause any great harm to the shrub apart from being, in gardeners' eyes, perhaps a little unsightly.  

Saturday, March 13, 2021

Another liverwort

I was scrutinising the top of Butterfly Rock today when I noticed a small green patch different from the surrounding mosses.  On closer inspection it was clearly a liverwort, lower plants closely related to mosses but with a number of rather variable distinguishing features.  Once one is familiar with a few species it is quite easy to distinguish them from mosses.

My liverwort looks like bifid crestwort (Lophocolea bidentata) a very common and widespread species that grows both on wood and rocks though I have not seen one in the Green Sanctuary for 17 years.  It is one of several strongly aromatic liverworts and I wonder what the purpose of evolving scent was.  There are various insecst that live in and on liverworts, but the plants would hardly want to attract those creatures that are inclined to eat them..

Thursday, March 11, 2021

Birch and bumble bees

In windy weather such as we have had today, I always enjoy watching the large birch tree in the Square Metre as it rocks backwards and forwards.  As well as sap drips, unopened catkins have landed all over the ground beneath and the twigs that come down too seem to be quite fragile, though the tree in general seems to be scarcely damaged.  Around the bottom of  the trunk the ground moves as the tree sways and it is a marvel that the roots can hold the whole overground tree upright.  I don't know the volume of the birch but it must be at least a cubic ton.  The ground doesn't sink as this, or any other, tree grows, so I take it that virtually all its substance comes from the atmosphere.  The picture below shows the base of the trunk.  Note the climbing ivy showing a preference for the rough, dark bark.

Despite the wind the bumble bees were still active though two of them sought shelter among low vegetation for ten minutes or so before off foraging again.  The picture below shows a buff-tailed queen well tucked into ivy and red campion leaves at the base of the birch.

Tuesday, March 09, 2021

The cherry log

Turning a little warmer with some nice sunshine on my back.  The large birch tree was dripping sap again and I noticed that some of the Muscid flies including the greenbottle Eudasyphora cyanella and a Phaonia  species were seeking out splashed leaves and feeding from them.  As well as liquid, the birch sap must contain a variety of nutrients so feeding on the splash marks makes good sense at a time when other food sources might be few.

I have put an old cherry log near Pork Pie Pond, a place where I can easily keep an eye on it from my bench.  This is partly to see if any fungi or invertebrates patronise it, but also because birds will perch on it.  If it works like Butterfly Rock their droppings may contain seeds that wash down to the base of the log to flourish in the well-fertilised soil there.  In windy weather caterpillars may be blown down from the large birch and climb up the log which they have mistaken for the birch trunk. Looking on top of fence posts near tall trees in windy weather often presents interesting larvae.

Today I was inspecting the log with my close focus binoculars when I spotted two tiny (about 1mm) cream coloured blobs on one of the cut ends.  They might be the droppings of some passing insect  In the photograph above apart from the blobs there are some tine white spots in a roughly rectangular shape lower down and towards the right.  These might be sporophores of a slime mould or just random motes from the wind.  Taking close up photographs of wild bits and pieces often reveals things like this not easily seen with the naked eye.

The western dandelion is now accompanied by at least two others that were seedlings last year.  They grew slowly during summer and autumn but have speeded up during the colder months and may flower this year.  However, on my visit on 11 March I discovered that abut half the leaves had been eaten, possibly by rabbits or deer.  I think they will recover.

Monday, March 08, 2021

Spring advances. News from the Rock

Still cold but signs of spring continue to appear.  On some of the seedling hawthorns there are buds breaking with bright green leaves.  There is a scatter of recently germinated seedlings on patches of bare earth.  Birds, particularly blackbirds, peck over the fallen leaves and today had managed to bury the eastern dandelion completely.  The eastern dandelion is having to compete with a young lords-and-ladies (Arum maculatum) which is, not surprisingly, larger than it was last year.  The birch tree continues to drip sap creating small splash sounds easily heard in these quiet days of Covid lockdown (though the children have gone back to school today, putting more traffic on the roads.

Butterfly Rock still continues to deliver interest.  The picture above shows that grass and sorrel is surviving among the moss on top of the rock while the pale green patch close to the centre is a lichen, possibly a Bacidia but I shall have to let it develop a bit.

Thursday, March 04, 2021

A cold March day

One of the things I enjoy least are cold spells in spring.  With the arrival of February some days of warmth happen.  Primroses, crocuses and daffodils flower, snowdrops are fading.  Then - bang! – the wind turns round to the north and a huge cloud-hung blanket of arctic air descends from the Polar Vortex or some other extreme weather circumstance at the top of the world.  Venturing forth in such conditions means the heaviest of clothes, fully drawn down hats and fingers frozen in the wind or from touching cold surfaces.  Precocious plants wilt, frost stricken and the black branches of winter trees rattle their twigs in the icy blast.  As one’s spirit sinks, the thought slinks into the brain that this might last for many weeks: March will go by, April get started and weather forecasts will still talk of late frosts and warn that “it is turning colder”. 

With these grey thoughts I walked down to The Square Metre in my slippers and gazed glumly at the winter flattened grass and leafless trees and shrubs with unbelief that the great summer resurgence is only a few weeks away.  But in my mind the chill was mitigated and the grey thoughts dimmed by the knowledge that the sunshine will come back with added strength, growth will resume and my spirits will return to a more acceptable place.

Wednesday, March 03, 2021

3 March 2021

Rather cold (9 degrees at midday) and with a thin mist everywhere.  I only made a quick visit to Emthree, but rediscovered the wild privet in Medlar Wood though it is well hidden in a tangle of tutsan and brambles.  The second privet is also doing well in the north east corner of the area but neither plant grows very quickly.

Looking back through past entries in early March, I noted that rabbits used to eat the pendulous sedge plant in Medlar Wood.  It does not seem to have suffered that fate this year, though it woulkd grow better if it had a little more light.

Monday, March 01, 2021

Lichens on twigs.

Today I spotted a small tuft of oakmoss, Evernia prunastri, one of the commonest and more easily identified lichens on a slender twig of the birch that I could just about reach.  Oakmoss is important in perfumery and has a large range of other uses.  One of its distinctive features is that the branches are paler underneath than on the upper side.

On looking at it under the microscope I noticed a much smaller greenish granular species dotted with dark fruit bodies.  It ran down to Fuscidea lightfootii in all my sources of information.  There were two further species on the small piece of twig I brought indoors: one with a very thin, greyish thallus and very few fruit bodies and another dark brown, very visceral-looking species that might be a Melanelixia.  The twigs were also heavily dusted with a green alga, probably a Desmococcus species.

The day after I discovered some beautifully patterned lichens on the smooth bark of the still standing pole of the dead ash.  These were readily identifiable as Arthonia radiata, another widespread species.  There was a second species with a very thin, grey and formless thallus scattered with rather few fruit bodies that will need further work to attempt an identification.  A good place to start with these is the Natural History Museum's publication Key to lichens on twigs.  This is also an online key A Key to Common Lichens on Twigs in the Key to Nature series:  https://tinyurl.com/2rzkjj53

Spring dandelions

My dandelions seemed to have disappeared during the winter.  Perhaps just covered in leaves, though they also lost there late summer leaves.  The more easterly of the two now has several healthy, but unusually narrow, leaves spread starfish-like on the ground. It looks as though some animal has had a nibble at the centre of the crown.

The westerly dandelion looks a little more tattered and there are three or four younger plants still further west.

Commentary 1st & 2nd March 2021

1 March 2021, St David's Day

Some oak leaves buckle as they dry in the sun, making a small clicking sound.

Sap is rising and there were glistening caps of liquid on the coppiced twig ends of the hornbeam cordon. Sap also fell from the birch in occasional drops and the twigs would bleed if cut.

Deep purple twigs that have blown down in winter storms are lying all over the Green Sanctuary - almost a protective net.

Yesterday I saw a small bird (chiff chaff or willow warbler) ferreting around the area. Maybe a new arrival or an overwintered bird.  It seemed particularly interested in the box bush.  Today I saw a wren and a robin while there were two hedge sparrows playing catch-me-if-you-can in the medlar.

Also yesterday I scraped some of the black patch that covers Butterfly Rock where it is bare of moss. I could discern no particular structure when I looked at it down the microscope later and it maybe that the sandstone itself turns black naturally if kept moist much of the time.  I have put it in on damp blotting paper in a small plastic container to see if it 'develops' in any way.

The wild onion bulbs have mostly divided underground and have produced many thin, sea green 'chives' over the last few weeks..  'Is there such a thing as a chive I wondered and in modern culture there is a verb 'to chive', e.g. Keep Calm and Chive On (KCCO). 'Chive on' seems to be a bit like 'rock on'.

I started to look at lichens..