Thanks for your Feedback Guillaume. I am also wondering if the sap-resin, especially for soft wood, would plug the gap in a relatively short time?

The small cavity in the tree can be a source of infections of the tyree.

Injecting the cavity with slightly heated asphalt will do the job and you can sleep on both ears. There are also liquid tubes filled with liquid artifical wood. The artificial on contact with oxygen, will become stonehard after injection in the cavity. Maybe more convenient than asphalt.

If you want to be sure you don't inflict damage and disease to your sample trees, try it out. I don't think the tree will die from it, on the contrary.

Cheers,

Frank

We have done a lot of coring of plantation pines and eucalypts using a 12 mm motorised corer that leaves a 22 mm hole. In radiata pine the resin bleed is usually significant and does a good job of self healing. Plantation eucalypts are very prone to decay and generally we find it best not to plug the holes. Plugging creates a moist niche that fungi love. It has been best to leave the hole to dry and let the tree cope.

I always like to think of it this way — branches break off trees all the time, animals dig holes into trees all the time, dendrochronologists take cores occasionally. All of these processes damage the tree, but you can bet that neither the windstorm nor the bird are likely to plug the hole they make. I leave the holes to heal naturally and sleep well at night knowing that 100 million years of evolution will take care of that hole (caveat: I mostly work with resinous gymnosperms).

These don't have to do with reparitive actions, but do find no increased mortality in sampled forests. I'm pretty sure these people left the holes open.

van Mantgem, P. J., and N. L. Stephenson. 2004. Does coring contribute to tree mortality? Canadian Journal of Forest Research 34:2394–2398.

and here....

Long-term effects of increment coring on Norway spruce mortality

Jan Wunder, Björn Reineking, Franz-Werner Hillgarter, Christof Bigler, and Harald Bugmann. Can. J. For. Res. 41: 2326–2336 (2011)

Nate and Geoffrey have given the best answers that dendrochronologists have come up with - let the tree's natural healing process take care of the wound. In high value trees, particularly hardwoods, where the spread of fungal infection from one tree to the next via the increment borer might be a risk I have heard of people using alcohol to disinfect the borer between trees. The wound will cause staining of the adjacent wood but generally the 5mm holes are closed by the tree in a year or two and significant long-term damage has not been found to be a problem. My nephew has made cabinets from maple boards sawn from trees that were drilled and tapped for syrup and the repeated wounding resulted in interesting staining patterns.

The work of Shigo and Marx "Compartmentalization of Decay in Trees" is a nice work on the general subject of wounding and decay: https://archive.org/details/compartmentaliza00shig

Daniel, As a forest pathologist I have cored thousands of trees including some 50 deciduous species. We were using the cores to examine radial growth response of diseased trees. In many situations we would revisit many of the trees years after coring to collect follow-up data on the tree's health, crown condition, etc. In many of these follow-ups I found it nearly impossible to find evidence that the trees were actually cored. The borer wound had healed over.

Being a dendrochronologist, I usually insert wax in the form of candle inside the hole after taking core samples. It will repel insects or borers and prevent the tree from further damage.

If you are really worried about this fill the holes with beeswax.. It's natural..

Sorry didn't see mr.sinha mentioned wax.. Didn't mean to troll :)

No problem, its ok. Actually you have clarified the wax i.e. Beewax. Thank you

don't put anything foreign into the tree.

The tree will quite readily fill the hole in itself

R

Beewax worked for me realy well. Also, I did not include in my research species like Oaks since that it was most likely not to ge permision to core those trees due to oak wilt. Other than that as Nathan English wrote, branches break all the time. The problem is more intense when sampling "Urban" trees.

Hope that helped,

Valasia

This publication of Grissino-Mayer 2003 gives a good overview of the injuries caused by increment borers. especially p 74-77.

And indeed, do not plug the hole. The only action to consider is the disinfection of the increment borer when sampling multiple trees and plots

Kristof..

I always worked with pine and we didn't plug the hole, only when I worked with disease trees, we disinfected the increment borer amongst trees.

Angela

Hi Daniel,

You might find theses two papers also interesting:

Mantgem, P. J. V., & Stephenson, N. L. (2004). Does coring contribute to tree mortality?. Canadian Journal of Forest Research, 34(11), 2394-2398.

Jan Wunder, Corina Manusch, Valentin Queloz, Peter Brang, Veronique Ringwald, Harald Bugmann (2013).Does increment coring enhance tree decay? New insights from tomography assessments. Canadian Journal of Forest Research, 2013, Vol. 43, No. 8 : pp. 711-718

(doi: 10.1139/cjfr-2012-0450)

best wishes,

Zoltan

Here are links to two online pubs that reinforce the idea that the best thing to do is leave the hole alone:

http://puyallup.wsu.edu/~linda%20chalker-scott/Horticultural%20Myths_files/Myths/Wound%20sealer.pdf

http://essmextension.tamu.edu/treecarekit/index.php/after-the-storm/tree-damage-and-hazard-assessment/tree-wounds/

After the sampling of Platanus hispanica, we put a dense mixture of copper oxychloride -Cu2(OH)3Cl)-to cover the hole and prevent fungus attack.

After the sampling of Platanus hispanica, we put a dense mixture of copper oxychloride to cover the hole and prevent fungus attacks in trees growing in urban places.

Claudia

Daniel, I should note that anything you use may harm the tree in other ways. Simply think of what bark do as a protector. Both bacteria and fungus can harm the tree. Besides, using toxic materials can harm the tree even more than a pest or pathogen. If you use bacterial fungicides, bacteria can harm the tree (not the bacteria you use as fungicides. but other bacteria). Best way is to seal just the entry of the hole. This prevents wood from draying and no fungus can live in there with no oxygen and high humidity.

There are plenty of expert suggestions provided already. I agree that sealing can potentially be more harmful to a tree than leaving it open. To contribute to the case examples, especially pines are very efficient in pushing out any externally introduced material and sealing the hole themselves with their own resin. Trees, in general, are very resilient. Your main concern should be keeping the corer clean to avoid spreading diseases.

See also responses to my very similar question asked on RG some 2 years ago:

https://www.researchgate.net/post/Does_increment_bore_coring_dendrochronology_have_any_negative_impact_on_cored_trees_and_or_forest_ecosystems

Best,

Lukasz

I remember I had this discussion with Fritz Schweingruber years back and he said that he always leaves them open so the tree can wash anything out rather then it being clogged up by some piece of wood or cork in the opening. He showed us the example of a tree at the WSL in Birmensdorf he kept coring and which was healing well - I wonder whether this tree is still alive?

Does anyone know if after coring teak, one should leave it open or seal it?

Yes it is better to leave as such without inserting anything from outside. Just plug the hole with your finger with protruding fibres that come out after removal of core samples. Cambium will be damaged when we insert any external things into the hole. Cambium helps in natural sealing process of hole

Pellacol could work if allowed fór usage.

Coring is also done in Pines specially bore hole method of resin extraction in Pinus roxburghii in India not recommended any plugging of hole. But it is advisable to plug the holes at the surface and rub the fungicide paste to check fungal infection.

En mi experiencia, al haber extraído muestras en caoba y cedro ellos rápidamente secretan un tipo de sustancia gomosa que en cuestión de 1 o 2 días solo se mostraba una cicatriz.

In case of beech (Fagus sylvatica), I read (I asled a mycologist) that the trees get inoculated by fungi through damages in the leaves, spores can penetrate in the cambium. Then adding oxigen or air flux within the stem it could trigger activation of the fungal grouth. Natural disturbances such windstorms cause breakage or cracks in branges. But I think it is up to a mycologist to answer this. Beech forests are known for fast decomposition of dead wood, and samples from "healthy " trees set into incubators had shown fast growth of fungi. I can add that trees have their own defense mechanisms.

Thank you for this question as well as for the responses... I really learnt a lot about this topic

Maybe some answers in the following paper (in French)

THIERCELIN, F., ARNOULD, M.-F., MANGENOT, F., & POLGE, H. (1972). Altérations du bois provoquées par les sondages à la tarière. Leur contrôle. Annales Des Sciences Forestières, 29(1), 107–133. https://doi.org/10.1051/forest/19720105

https://www.afs-journal.org/articles/forest/pdf/1972/01/AFS_0003-4312_1972_29_1_ART0005.pdf

I used common mastic for pruning - which contains some phytohormones - to cover the holes made by the corer on hundreds of beeches, silver firs, and some Hungarian oaks. Results were very good; after 1-2 years, the wounds were perfectly closed and no signs of infection were (visually) detectable. This simple treatment was applied immediately after the cores were extracted.

For dendro sampling, it is recommended to let the holes empty. If we will fill the holes with different materials (gummies, mastic, etc), we will create the perfect medium for fungi development (lack of oxygen and full of moisture). I prefer to clean the with 50% alcohol to disinfect it, and after to use a WD40.

I do nothing, and as many other said, trees are well beyond stronger than a small hole.

I agree with Catalin-Constantin Roibu

I agree with Mauricio Fuentes. In addition, I see that many trees that I have cored and treated with mastic over time have rapidly restored the tissues. Gaseous flux exchanges are - in general - higly limited by the closure of tracheyds, fibrotracheyds, and vessels that insulate the chamber inside. This may cause blocking or strongly limiting the exchange of any gases, including the gases used by anaerobial microrganism. Trunk decay is anothe matter.