Re-pollard of ancient Willow

[Tony Croft aka hamadryad]

heres a nice willow, now, a good one because it is a very large wood heavy tree (weeping willow) The first stage was a heavy reduction with retention of foliage to stage pollard it. The staged approach i chose because i was not sure how vital and vigorous the tree was or rather i had a feeling from the body language that there was good health and vitality but didnt want to risk the failure of regeneration due to massive wounding and starvation (carbohydrates via photsythetic area loss) which might have tipped the balance in favour of the decay organism present in the ripewood region due to a massive low limb being removed decades before.

 

It was clear that adaption had taken place and that strong vascular/root connections where very active and functional as the force flows where strong in the helical fibre lay. this would be expected as the tree crown meant that its weight was trying to twist and turn down on the weakened main stem.

 

Its very difficult to explain things that you know by instinct and do no longer need to think about too much, its second nature.

 

 

 

 

[David Humphries]

David & Simon,

Are these weeping willows too ? Tomorrow, I'll make some photo's of the lesions and cracks, that are already there.

 

Yes Gerrit

 

Riverside in Ely, Cambridgeshire

 

.

[Treecreeper1961]

Sorry I missed this post earlier:blushing:

 

A lot would depend on previous dysfunctional volumes and their position in relation to the desired pollarding.

 

This is going to take some time to answer as I now have to refer to the BS 3998 2010 to see what your referring too. thats not to say i dont know and therefore do not work to BS 3998 because i work beyond the standards.

 

could you state and number the question in a less ambiguos way so that i can be precise?

 

Yeah sure.

 

BS3998:2010

 

P31, 7.10

 

Pollarding

 

The document recommends that pollards which have lapsed for many years should be crown reduced rather than cut back to the knuckle in one go (pole thin). It is also recommended to leave live growth and select stems to be retained for photosynthetic energy. Cutting live stubs is also recommended to create new growth points and reduce the possibility of dysfunction spreading below the knuckle or original pollard.

 

Looking at the original photo in this thread:

1. Would you consider the pollard to have 'lapsed for many years'?

 

2. Would you consider a more phased approach to re-establishing the cycle of this pollard or indeed crown reduce it instead?

 

3. Would you treat other spp. differently to willow?

 

4. When undertaking following cycles at the interval you stated, would you endeavor to leave live growth where possible or do you consider the way willow responds makes this unnecessary?

 

Also,

5. with willow's poor compartmentalisation ability and lack of heartwood should extra attention be paid to minimizing dysfunction and creating a knuckle or does the proliferation of regrowth make up for this?

 

And,

6. do you know how long willow pollards in proper cycle will live and remain viable compared to other species?

 

7.On what basis do you recommend the re-pollard cycle, ease of management, best practice to minimize dysfunction, produce, aesthetics or all of these?

 

Have just initiated a candelabra pollard on a willow approximately 30cm diameter at 4m in a woodland setting!

Will await response with interest.

 

Ben, or as someone recently called me, Creeper.

[Treecreeper1961]

Apologies, you have answered much of this in your last post.

[Tony Croft aka hamadryad]

Apologies, you have answered much of this in your last post.

 

one thing i always swear by but many are not convinced its of value.

 

Where dysfunction/wounds/decay exist i ALWAYS leave as much growth developing at the point nearest the wound and as long as possible.

 

Why? because A) it makes resource allocation transport distances far less which in an old tree that may be moving to a sensecent state can be a major player.

 

B) because if growth is allowed to lengthen it will also thicken and result in larger shell walls at the area of worst mechanical stress.

[Fungus]

Tomorrow, I'll make some photo's of the lesions and cracks, that are already there.

 

Documentation of the delamination, lesions, cracks, holes (cavities), fresh or old and not (entirely) closed "natural" and pruining wounds and the presence of fungi.

The willows will have a hard time keeping Pleurotus ostreatus and Flammulina velutipes (and/or Polyporus squamosus, Trametes species, Daedaleopsis confragosa and Chondrostereum purpureum) from invading the trees through the wide open wounds, because the trees are in rest and can't defend themselves during winter time.

 

Photo's 1-4 : delamination, lesions, cracks and holes (cavities) in far outreaching branches

Photo's 5-6 : fresh or old and not (entirely) closed pruining wounds

Photo 7 : fresh "natural" wound after the storm tore off a limb (photo 8)

Photo 9 : Stereum species on a branch

---

Edited November 25, 2011 by Fungus

[Treecreeper1961]

Documentation of the delamination, lesions, cracks, holes (cavities), fresh or old and not (entirely) closed "natural" and pruining wounds and the presence of fungi.

The willows will have a hard time keeping Pleurotus ostreatus and Flammulina velutipes (and/or Polyporus squamosus, Trametes species, Daedaleopsis confragosa and Chondrostereum purpureum) from invading the trees through the wide open wounds, because the trees are in rest and can't defend themselves during winter time.

 

Photo's 1-4 : delamination, lesions, cracks and holes (cavities) in far outreaching branches

Photo's 5-6 : fresh or old and not (entirely) closed pruining wounds

Photo 7 : fresh "natural" wound after the storm tore off a limb (photo 8)

Photo 9 : Stereum species on a branch

---

Fungus,

Whilst the 'style' of reduction may be far from recommended practice there is some really nice conservation value in some of these features, which have been maintained by the manner of the work, by fault or design. If some small live growth had been retained it would have been better.

Nice bat roost potential in the hazard beam type split.

[Fungus]

Whilst the 'style' of reduction may be far from recommended practice there is some really nice conservation value in some of these features, which have been maintained by the manner of the work, by fault or design. If some small live growth had been retained it would have been better. Nice bat roost potential in the hazard beam type split.

 

My prediction on the condition and survival of both weeping willows for the near future (within 5-10 years) is, that many of the major limbs will desintegrate under the meanwhile (again) too heavy weight load and torsion forces and the bats will be homeless by then, so where's the (long term) conservation value in this approach ?

[Treecreeper1961]

My prediction on the condition and survival of both weeping willows for the near future (within 5-10 years) is, that many of the major limbs will desintegrate under the meanwhile (again) too heavy weight load and torsion forces and the bats will be homeless by then, so where's the (long term) conservation value in this approach ?

That is a more than fair comment, but all reductions and pollards are a commitment to long term management, are they not?

If that open split was a known roost then it would be justifiable to manage the tree for that one feature alone, in my opinion.

Unfortunately, there are precious few trees that offer valuable features and those that do should be cherished. I see what you are saying and perhaps i am playing devils advocate to an extent. Willow may not be the species that offer long term stable habitat in any case. If the feature was a deep cavity in the trunk offering nursery roost potential then there would be no question. That split is almost certain to be used as a roost at some point, in some way, and is therefore protected by law, is it not? If we want to protect the future of sensitive species we are inevitably going to go to stretched lenghts to succeed.

Trees are the center of a tree specific ecosystem.

[Tony Croft aka hamadryad]

That is a more than fair comment, but all reductions and pollards are a commitment to long term management, are they not?

If that open split was a known roost then it would be justifiable to manage the tree for that one feature alone, in my opinion.

Unfortunately, there are precious few trees that offer valuable features and those that do should be cherished. I see what you are saying and perhaps i am playing devils advocate to an extent. Willow may not be the species that offer long term stable habitat in any case. If the feature was a deep cavity in the trunk offering nursery roost potential then there would be no question. That split is almost certain to be used as a roost at some point, in some way, and is therefore protected by law, is it not? If we want to protect the future of sensitive species we are inevitably going to go to stretched lenghts to succeed.

Trees are the center of a tree specific ecosystem.