David Humphries

A return to the trees of northern Spain Beech pollards at the Urkiola Monastery October 2017 Context A 10 year project sharing experience from the UK, Sweden & Spain on the ecology, cultural importance and vulnerability of pollarded trees across Europe. The Basque area (as well as similar UK sites) have many examples of where pollards left out of regular cutting succumb to dysfunction, decline and fungal colonisation by Kretzschmaria deusta, Meripilus giganteus , Fomes fomentarius, Ganoderma pfeiferri & G. australe leading to part or whole tree failure. The project has been focusing on the most successful ways of restoring lapsed pollards by a range of reduction techniques, to mitigate failure & decline. Wind loaded pollard failure associated with Fomes fomentarius 2017 Root plate pollard failure associated with Meripilus giganteus 2009 2007 A comparison of pollarding techniques was undertaken across the Basque region at various sites. A total of 38 lapsed pollards were cut in the Basque tradition (using axe/chain saw, down to just above the bolling) and in the Epping Forest and Burnham Beeches styles (using chainsaw and handsaws at a higher level in a phased 5-10 year cycle. 27 trees were cut by Spanish arborists and 11 cut by UK arborists , with both sets of climbers mixing styles. Basque style Epping Forest style Burnham Beeches style (Image taken by H. J. Read) 2009 After three growing seasons a team of ecologists and arborists from the UK visited the three sites and measured the vitality of the canopy growth and decline of the target trees to assess the response and reaction to the cutting. Among other things like general vigour, the length & diameter of cut stubs, how many new shoots and clusters of epicormics growth were recorded from 10 cut branches from all cardinal points per tree. Measuring on an Epping Forest style repollard Measuring on a Basque style repollard See previous blog entry & thread on the 2009 trip for further context….. Jan 2013. Observations of the 2009 measuring/recording were presented in the Read et al paper published in the Arboricultural Journal - ‘Restoration of lapsed beech pollards: Evaluation of techniques and guidance for future work’ Helen J. Read, Jeremy Dagley, Jose Miguel Elosegui, Alvaro Sicilia & C.P. Wheater. In conclusion the paper suggest that the pre-cutting vitality of a pollarded tree is an important factor and that retaining stubs of at least 500mm may be significant in the development of dormant buds. Avoid cutting branches over thirty years old as the ripe wood begins to deteriorate and the tree is less able to occlude wounds. 2017 A UK team from the City of London Corporation Open Spaces spent a week at the European Symposium on Pollarded trees, visiting sites, discussing experience on lapsed pollard restoration & looking at the natural heritage of the Basque region of Spain Image taken by Jez Young Monday On a drive south from Bilboa in to the Navarre region, our group stopped off at the Monastery at Urkiola to see large numbers of lapsed beech pollards. Tuesday Pollard Symposium at the Leitza Town Hall The conference started with a set of presentations on the veteran trees and pollards at the four Open Spaces of Burnham Beeches, Epping Forest, Ashtead Common & Hampstead Heath. Followed by presentations from Ted Green MBE, Ecologists and Arboriculturists from Sweden and Spain. Image taken by Jez Young Question time followed by a fantastic exhibition of cross sections of local ring & diffuse porous tree species Wednesday. Urkizu - pollard restoration work. Revisiting some of the 2007 cut pollards. 2009 2017 After an interesting hike up into the hills above Leitza, looking at pollards and Basque living heritage on route, the group participated in a field work shop with Spanish Arborists (Samuel Alvarez & Oriol the axeman) with the aim of further restoring a lapsed pollard (last reduced in 2007) by axe & chainsaw being directed by CoL Ecologists and Arborists. Thursday Urbasa-Andía Natural Park in western Navarre A visit with Swedish ecologists and members of the Ancient Tree Forum to see oak, beech & maple pollards in wood pasture grazed by horses & cattle. Maple pollards Oak Pollards Friday Oianleku - Aiako Harria Natural Park Revisit to the 2007 City of London cut pollards as well as assessing an area of Spanish hard cut pollards which appeared to have a high mortality rate. The Future Whilst the tradition of pollarding younger trees for winter fodder continues in the mountains and foothills of the Basque country, the project is ongoing with a few keen people cutting just a few old pollards each year and trying to source funding for the restoration program into the future. There is an appetite for an ongoing collaboration with Basque & Spanish arborists with the potential for working visits to the UK to work with Arborists in Suffolk and with the City of London Teams whilst working on the veteran pollards at Burnham Beeches in 2018. This was yet again an amazing and inspiring trip and I very much hope to return to enjoy the heritage and tradition of the Basque way of life. [email protected]

Hello Mark, secondary clonisations by saprophytic fungi (like Pleurotus sp) are very common on wood volumes that are infected by a primary agent like Kretz. But unless the subject tree is in a woodland or away from significant targets the overlapping successional species are seldom seen by Arbs as the risk averse nature of tree ownership and management usually means that the ‘hazard’ is removed.

Great shots and nice variety, new forest is a rich landscape for fungi.

Need to see images of gills and stem really.

The chips are plastic coated and designed with an operating life of over twenty years. Will be interesting to see how many of the 900 are still operating.

They're all called David ! Well they are 'my' trees after all

During a survey of our sites veteran trees in 2007 we trialled the use of microchips as a means of identifying the trees without the need to have a metal tag showing. Basicaly we used pet microchips that were inserted about three centimetres into the sapwood on the northern side of the trunks @ 1.5m height. There were concerns that over time the microchips wouldn't be effective due to interference by birds (on the first trial a woodpecker had obviously detected the tiny hole and sensed the chips presence as one had been pecked out) and also by the expanding annual ring growth and by compressive forces. We're currently resurveying the veteran trees and have been pleased to find that 10 years on the microchips are still emitting their signal so we can pick up their unique identification numbers.

Was it a red chestnut, Aesculus x carnea ? if it was, they are prone to burrs on the trunk, main scaffolds and lesser branches. presumably due to being a hybrid. .

Great article Andrew, nice mix and choice of species to highlight and overview.

No idea, never been to Arizona, think I'm probably banned from the State I have seen our native ash and other species do this though, expect it was initiated by a mechanical wound earlier in its life where cell division at the callus tissue has formed into roots.

Inosculated aerial roots on this Arizona ash, Fraxinus velutina var loumeyi at Kew Gardens. Couple of images taken 5 years apart. First one was taken in May 2012 and the second image taken today by Ted Green. Some secondary growth thickening in evidence but not as much as one would expect, even the wound wood on the pruning wound is relatively limited in terms of occlusion. Perhaps a good mulching to improve the rooting environment and keep those over enthusiastic snappers a bit further away

Ganoderma sp, probably G. australe

Another red oak with evidence of a basal colonisation (this time) of Pholiota squarrosa We've carried out micro-drill readings and sounding with a nylon hammer which indicates that the (now) forming semi autonomous units (root/buttress units) are currently vascular & sound enough to retain the tree. This one has a very good Potential Roost Feature (PRF) in the trunk. Canopy has been reduced up to 2m to lessen the wind load on the sail. Rob Taylor/Dendrophile in the harness

Bit of a head scratcher to make this one safe. Ali Nicoll in the harness...........

Aw shucks, you got me all embarrassed like Don't know about this science business, observational backbone perhaps. Anyhows, can one address me as Dr Humphries from now on please, I received a package from Oslo University this morning that say so.........so it must be true

Split leaning willow that we had reduce due to being with in falling distance of a property. Lower section of trunk has been retained standing, but the upper section had to go. Probable Laetiporus heart decay has been 'sounded out' by a woodpecker for a potential bit of future habitat.

Early autumnal drift in London, showing the difference between species as the floating leaves are from a red oak (out of shot) and the tree to the left, an English oak, which is way behind its American cousin

Great observation and images Mr ArmyBloke Think these are probably Armillaria sp though rather than Pleurotus sp, classic ring on the stem. Would be interesting to see how far the rhizomorphs have progressed under the bark. We were discussing this on a thread that Sloth put up recently.

They look like Chi Chi's, aerial roots sometimes found on stressed Ginko Pretty cool

The trees have awoken this morning and are staring back !

Veteranisation techniques, mimicking woody's on some of the stem, is all I'm saying, well that's what I'm sticking to

Loves a bit of Coronetting from ladders

Oddly I can now see them, think Graham is on to it. Gills look to be lilac-ish in these images, which is a good I'd feature for blewits.

Can't see any images

http://www.bbc.co.uk/news/av/uk-england-hampshire-41794732/new-forest-champion-arboriculturist-talks-about-her-love-of-trees Short piece on Jo Hedger talking about comp climbing and life amongst the trees