Getting a permit to core trees at the Arboretum!

[christophe-rd]

Lizzie and I are working on getting a permit to core trees at the Arboretum next spring. Here is a list of the trees we have phenodata on: https://github.com/temporalecologylab/treespotters/blob/a8b38ae093387dc1a15ce09914be212b5cbe4fe5/analysis/output/treeswithPhenodata.csv

[christophe-rd]

@lizzieinvancouver emailed Faye Rosin (Ailene suggested to reach out to her)

I am writing as I would like to core the Tree Spotters trees (see list attached) to test whether phenological season length relates to growth. This is a major question in fundamental biology but also critical to forecasts of climate change itself, since most carbon models assume that plants experiencing longer seasons will sequester more carbon. We have a good number of years of Tree Spotters data now and almost no one has coupled ground observations and growth data, so it would unique opportunity. We'd like to take two cores per tree (but could get by on one) and would follow all the protocols Ailene used (disinfecting corers etc.) to minimize damage.

Do you think that Curation would be open to a proposal on this? And, if yes, do you have any advice on how to start the conversation with them?

and she wrote back:

I think that Curation would be open to your proposal. Michael [Dosmann] and Kathyrn [Richardson] will have a proposal for you to fill out, but I think it doesn't hurt to email them first and ask the question. They can give you the form but that way they are expecting it and if they want you to include something specific based on your email, they can ask you to include it.

[christophe-rd]

Proposal submitted! Michael asked:

We'll take a look and get back to you with any questions or updates. I know that some of the trees on the list have perished/gone into decline (namely I'm thinking about the Fagus grandifolia due to beech leaf disease), so some of the candidates may no longer be available. I did have one question: Is there a reason why you would like two cores per tree, rather than one? And, is there any particular method you'll apply when gathering them? i.e., 90 degrees away from each other, directly in line vertically but 5 cm apart, etc? The stressors (biotic as well as abiotic) the past few years have been piling up, so just being conservative in our review.`

Lizzie replied:

Taking two cores is standard to allow cross-dating within a tree (e.g., see https://www.researchgate.net/publication/259466472_Fundamentals_of_Tree_Ring_Research). It helps us remove effects of lighting/shading as much as possible. This means we usually take cores from opposite sides of the tree at the same height (breast height is standard), picking the sides to maximize potential environmental variation. We have tried skipping this step, but found the data quality goes down substantially and we're not as convinced we're getting the years correctly matched with just one core. If you're very concerned, we can reduce to one core per tree, but we'd prefer to do it for only a limited number of trees and ideally not all of the individuals within one species (so that we can look at the cross-dating within a tree for all the species).

In terms of disease, we have a stringent process of cleaning all our equipment between each tree we core so that's our main approach to preventing disease. There are ideas that coring at a slight angle or filling the core with some material could help wound recovery, but there's no evidence this helps (and I believe now some evidence it does not help) so we take standard cores at breast height. There's ample evidence that coring does not hurt trees, nor does it impact mortality. My colleague, Neil Pederson, keeps a list of references relevant to this that I can share if you like.