Oak deaths due to excessive light at night?

MzHopsing · Mar 7, 2018

Hi all - I recently finished a fantastic book (The Hidden Life of Trees - Wohlleben) that was packed with tons of mostly footnoted facts, a bunch of which I was unaware. One explained about how trees need to rest at night like people, and how city light affects seasonal dormancy and tree health. He mentioned an American city (Wohlleben is a forester in Germany/central Europe) whose oaks were suffering, and that 4% of them had died because they were subjected to light every night. Unfortunately, this info was part of a 1981 report in a German journal called Gartenamt, and my online search to discover where this happened, and if they remedied the problem in time, has been fruitless. I figure if it made it to a German publication, surely it had to be in one on this continent...?

I know solving this is a long shot, but I know some of you guys have been doing this awhile, so thought I'd throw this out there. Any arborist/environmental entities that might include this story that you might know of?

ATH · Mar 7, 2018

Searched Journal of Arboriculture archives...found an article from October 1975 "Security Lighting and its Impact on the Landscape". It lists the oaks as having "low" sensitivity to the lights... But location and intensity of the lights will be a huge factor in whether or not there is even a chance of impact.

MzHopsing · Mar 8, 2018

ATH said:
Searched Journal of Arboriculture archives...found an article from October 1975 "Security Lighting and its Impact on the Landscape". It lists the oaks as having "low" sensitivity to the lights... But location and intensity of the lights will be a huge factor in whether or not there is even a chance of impact.

Oh wow, I knew it had to be a ways back, but you found it! Thanks ATH!! Does it talk about the deaths of the trees or where it happened? I have so many questions...

ATH · Mar 8, 2018

You an ISA member? I know you can get it online if you are. Not sure if non-members can or not???

It looks like you can as I'm not sure I've logged in on my phone and it let me:
http://joa.isa-arbor.com/articles.asp?JournalID=1&VolumeID=1&IssueID=10

jomoco · Mar 9, 2018

Just finished Wollebenn's book myself.

Probably the best book I've read on trees to date, easily the most fascinating, with an emphasis on how little we know about them, compared to how much we've yet to learn.

I had high hopes he'd do a chapter on Ghost Redwood's, however he did explain how root grafting between related species can and does allow a tree with zero chlorophyll to survive among friends n family.

https://www.mercurynews.com/2016/09...ystery-of-ghosts-of-the-forest-may-be-solved/

Jomoco

MzHopsing · Mar 9, 2018

ATH said:
You an ISA member? I know you can get it online if you are. Not sure if non-members can or not???

It looks like you can as I'm not sure I've logged in on my phone and it let me:
http://joa.isa-arbor.com/articles.asp?JournalID=1&VolumeID=1&IssueID=10

Thanks so much ATH!! When I did a prelim search yesterday I read that there were only full articles for 2002 and on, so I didn't even go any farther. This is far more than I hoped for! I'm not an arborist, just an enthusiast, so not sure they'd accept an app from me....

Again, much thanks for digging this up! You rock! :numberone:

EDIT to add: I just read through that article on security lighting impacts, and there's no mention of the town or deaths of trees, so it's possible it's in one of the 'sources of additional information' listed at the end. There's one called 'Dormancy of trees in winter' that looks hopeful, so I'll dig for a bit longer...