CambridgeJC

Upwards is geotropism. But I am just a scientist 🤣🤣

Alec is quite right but not about me dismissing those who do not support my contention. I am asking for data which both supports and refutes it. So far without much luck. I am attracting a lot of aggressive dismissal without supporting evidence myself. I am keen to ask for hard evidence. I do not dismiss text books written by authoritative persons but Knowledge moves forward and especially in the field of genetics and ecological environment. There is more being learned every day so not good enough to simply regurgitate so-called facts from the literature without a degree of caution. Learning can be uncomfortable for those who rely on previous knowledge without question. Learning consists of building on previous knowledge and modifying that if new evidence arises. But in principle you are completely correct. My quest is for this potential new evidence based simply on my personal observations which may or may not be consistent with an increasing threat from ivy for whatever reason, climatic or otherwise.

Because that’s what other contributors are saying. They are the arborists…not me. See earlier posts here.

Before someone takes this out of context I am NOT saying ivy kills all trees…just those on which it creates a sail for the wind to bring it down. And I fully accept not all those are healthy trees. But more and more will succumb to ivy canopy growth as time goes on.

Great. At last someone who is prepared to stop and think. Using his brain. And not simply accepting stuff that he has learned at college or from books. Someone who has eyes to see and uses them. And a brain to think and uses it. How many of you there can say that? Common sense prevailing at last??? Ivy doesn’t kill trees. That’s the bullshit.

If that’s true then this is the last we will hear from anyone. Actually this has been an enlightening experience so that’s fine by me.

No. But I have learned a lot about this subject and the most significant finding is just how aggressive some of you arborists are and resistant to a simple request for information. You encourage me to continue to get at the facts as far as they exist. It id a real challenge but you guys really do have a grass roots knowledge which is valuable. But maybe try to remain open to this bullshit as you call it. Perhaps some of it is not so off the wall.

If you are up to it, read this… https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4829722/ It almost certainly applies to ivy and explains the diversity of local ivy cultures in our environment. And the mechanisms involved.

…probably…or maybe not…

Absolutely right Sutton…feeble 🤣🤣🤣

Its all a bit earlier in this page

Hello Mick. So now you suggest that I am creating an apocalyptic certainty!!! You credit me with rather exaggerated powers…and with no evidence. Wow!!! You are do determined to discredit me and pick little holes in my contributions that you fail completely to understand my motives. Simply to encourage you guys to make mature and informed comments based on actual experience which I fully admit I do not possess. I seem to have rubbed you up the wrong way for which I cannot apologise as it has prompted a display of the confrontational approach adopted by a very few arborists. Most have been very measured in their response and it seems many arborists confirm the extent of ivy penetration into our environment. Possibly even a mature concern. So let’s just stick to facts and observations rather than focusing on confrontation. Please. Have I offended you with my punctuation?

You get me wrong here. I look for data to either support or to negate the proposal that ivy is an increasing threat to our uk woodlands and hedgerows. My personal feeling is that it possibly could be and if it is then it should be evaluated and control measures adopted. Thanks for prompting me to clarify this.

I love this. Some good old British humour. Well done 👍

Lets go back to basics. Most high winds occur during winter. Certainly in temporate regions. And the trees which populate extreme windy regions are guess what? Pine forests. Wow! And these are guess what? Evergreens. Wow! So what did they do to evolve to cope? Guess what? Roots that held them fast and strong in the face of high winds! Wow! Clever little devils these pine trees! And many also developed spiral fibrous trunk growth structures. Wow! This creates strength against wind stress and leverage. Clever stuff eh? Wow! And not content with that under the years of exposure to prevailing winds they even develop growth tendency to lean away from the wind above ground. Pretty basic stuff here. But they counterbalance the consistent strain by root structures on the opposite side to anchor themselves firmly into the ground against the anticipated wind stress. Not a lot of people know that. (Michael Caine may have said that🤣). But in warmer climes broadleaved trees grow in forests and cultivated in isolation and are deciduous in the main. They have evolved with shallower root systems compatible with luxurious plant growth soils and increasing rainfall and ultimately rainforest conditions. So when the wind blows their shallower root structures are less able to cope. Some are able to evolve genetically and phenotypically to protect others at the borders of a forest in windy areas (like Dartmoor for example). Just look at the isolated copses there. Always shaped with low growth on windwards edge and rising away to leeward. Same for individual trees there. Clever little souls. Much to be learned from trees. But ivy changes things. As they have found to their cost in the USA. Where it is declared an invasive species. It tends not to grow on evergreen pines which shield them from light source and have a wonderful time when deciduous trees lose their leaves. Smart eh? It grows exactly the same here in the UK when left to its own devices. No difference at all. But we choose to call it non-invasive. Because it was not introduced from abroad!!! Whose clever idea was that??? Hmmm! Now lets get serious. How do we want our woodlands and hedgerows to develop in future? Covered with evergreen ivy growth to the detriment of other species? Torn down any time the wind blows hard? If so then carry on as we are. Do nothing. I have images of Hedera helix growing as juvenile form up quite high with no sign of development into mature reproductive growth. And loads of ivy covered tree trunks not acting as sails. The chance we have just now is getting data on WHETHER OR NOT ivy is a threat to our trees and hedgerows. So…please help collect data on the proportion of downed deciduous trees that are loaded up OR NOT with ivy growth which has contributed to the fall in this week’s high winds. That will provide useful information and allow a mature and informed discussion on the subject. OK? Just forget the science and other distractions. Focus on understanding the question and collecting some basic data. Unscientific this may be but at least its a start. Or maybe I’m just unhinged 😂😂😂

Please explain yourself

Aha…so that’s what this is all about 🤣🤣🤣

Are not Leylandii evergreens?

Ivy in local trees can develop large cloud-like top growth which acts much more like a sail and has much greater leverage to snap a tree off at its base. Before this the ivy creeps close to the trunk which does not really act as a sail so much. See photos here in Wandlebury. All isolated evergreens will catch the wind but are inherently more resistant due to root structural strength and evolutionary ability to resist leverage forces. Many photos taken before this weekend. Will be keen to review after storms.

Question…with Eunice on the way, who would wander in a wood? Answer…Edward Woodward would🤣🤣🤣

This weekend is a perfect opportunity for all arborists to report the ratio of trees brought down as heavy with ivy or unaffected by ivy. Just an idea of workload for both types needing clearance after the storms. Images and numbers for all fallen trees would start to provide evidence either caused by ivy or not. Then we have some data even if it rather an uncontrolled experiment. Anyone up for this? Ask a friend!!!?

So we shall see how many trees are brought down by their ivy sails…remembering of course that ivy does not kill the trees…just the wind…

Paul wondered why other trees showed no signs of ivy. I returned to check and discovered all other trees had had the ivy cut across about two foot above ground level so had died completely. Clear signs of deliberate control with decisions to retain at least this beautiful old specimen. See surroundings in attached image with old one in background. All others around had similar treatment with dead ivy left to rot away. A few others allowed to retain ivy. Plenty for animals without risk of overload.

Ok. Great thanks. I was using iPhone. Attached same tree today…

https://www.thefreelibrary.com/Heteroblasty--a+review.-a0259155098 Hedera helix changes from Juvenile leaf/shoots which spread and explore the ground and plant growth looking for suitable bushes and trees on which to climb. When found the ivy is signalled to climb and changed to the mature reproductive form with the bushy ivy that is seen in the canopy. This ability to mature and change is called heteroblasty. This link takes you to a very comprehensive review of this which is highly relevant to ivy. Worth a read when you have time.