| [College of ACES] | [University of Illinois] | [Illinois CES] |
No answers, but few comments. Everything alive, is a complex organism with chemical and physical reactions. As we know, extreme conditions (temperature, drainage, pH,...) are difficult situations where nature has to equilibrate that, one way or the other. Human, animals, plants, are very sensible and have facilities to adapt but when time is available. It may be quickly visible, as it may need more time to be identified.
I hope some people have hypothesis or facts. In this case, we don't know how far is the mechanism of abscission and related reactions completed. 40, 60, 85, 99%? It may be completed (at least for natural protection against diseases...) as well as it may not be safe. For sure, leaves are a heavier weight and a higher risk for climate agents (snow, ice) which may have consequences.
But, if you don't have any answers, you have a great subject to study at the university. Winter is a good time for you to prepare a scientific method to study it next spring and maybe for years to come. Few plots here and there to check trees and sample them would help to have a better understanding of this case.
El Nino, pollution, climate cycle,... may be a part of this unbalanced situation. We may have to encounter more and more new challenges like this around the world. Think globally, act locally!
Good luck,
Andre
A forest technology teacher