CambridgeJC

I tried but don’t see date stamps. I do see that these two are compiled image sequences which utilise different age images. I can see two images of the sane tree at top of the same road as attached here. And the new Croudace development in Linton is shown at the same time as my long gone car from about 2005 so around 17 years ago!! See the same tree with and without ivy! Your links are really informative!

Here are the two images taken from your links. Please describe them with the time difference. Thanks

Alec. You are just around the corner to me in Linton. Your links are really helpful. Are the first two on different years? I can find my own image by running the links forward. Just what I need to make a comparison. But I just need the dates for each. Thanks

Can you be a bit more specific? You may have a point but just saying this simply fails to make your point. It only suggests that you are the only informed person which simply cannot be true. Give us a chance to agree with you by providing an example. Please. Thanks

Good question Mick. Is it possible that the tree just manages to keep growing beyond the growth of the ivy??? Have you a camera on your phone? If so you could just take a few snaps and show us whst you mean. I fully believe you. This is most interesting and a good observation. Thanks.

Please all calm down. To get things clear. None of those in this forum are tree huggers and noone is unhinged either. We can all learn from each other as we all have different backgrounds and experience. I have learned loads from you guys recently and want to learn more. I also have other sources of knowledge and can bring something to the discussion despite not being an arborist myself. May I ask a question about trees which attract ivy and those species which manage to avoid it here in the uk? Maybe Mick can explain this as he does seem to know quita lot. Thanks to all.

I am careful NOT to say ivy kills a tree. Except when it causes the tree to uproot or blow down. Or become susceptible to infection due to abrasion or other physical damage. This reference has again been used as a source of fact when it is an article written originally 22 years ago by Andrew Cowan and his company web site. In those days there was far less known about this issue and it is high time for an up to date review of facts and figures as well as a full understanding of the development of ivy in the uk landscape as a whole. So we need facts. I am fully aware of historical attitudes to this thorny issue. Sorry no thorns though in this case.

Thanks so much for your really helpful and measured response. When I say I am fact finding I mean that I am learning about the basics of ivy and its spread and habit together with the reality of its apparent heteroblasty and effects on surroundings and ecology. I am a total beginner in this field and have come to this forum to learn. I am giving my reason for learning about ivy as I am concerned about my local observations of damage I see more and more recently in a wide area here in the east as we travel around and walk into the countryside around as we go. The response has been both informative and occasionally very defensive of estabished understanding. At this point I have little evidence of any major change in invasive changes but my images contain many examples which could just be the result of neglect or could be more sinister as a result of climate change or even an unexpected result of advice by authorities and advisers to leave it alone to take nature’s course. My research is personal. To learn my subject before any accumulation of evidence to support any theory. My research at this is not an accumulation of evidence. So your comments have been really helpful to prompt me to explain my current position. Some facts I have learned: Hedera helix is the most likely species involved. Hh develops from juvenile exploratory plant into the mature reproductive heteroblastic form. The mature plant is used by a wide number of animal and insect species as cover shelter and habitation as well as food. Hh can grow high into the canopy. Hh can in some cases become heavy and act as a sail to create leverage during high winds. Hh does not need to grow high in a hedge to act as such a sail. Hh provides valuable habitat and food source and is not always destructive. Hh can cause danger and or damage to trees and persons if not managed appropriately in such locations. Hh is considered an invasive species in the USA as an imported species from Europe. Hh is not considered invasive in the uk because it is a native species. I don’t need evidence for the above facts. They are both self evident and well accepted facts. I am simply asking for information from knowledgeable and involved people on those issues and facts which impact on the subject. Hence my request for information from arborists. I am noting all comments including those which are critical of my approach. These are in fact very informative as they convey the current opinion in a factual form. So once again thanks to ALL contributors and responders.

I have already told everyone that I am a retired scientist and of course have had education and experience over my own three score years and ten. I am keen to learn from informed persons on the subject of ivy encroachment or otherwise in the uk. All contributions are welcome as they can help sort out fact from opinion. Perhaps those guys who are critical of my approach could just inform us all exactly what they do and how much education (you may call this training if you like) that they have had themselves. I have already answered that question from Mike. It’s your turn now. Then we know what we are dealing with. So far I have not received much in the way of facts … only subjective comments on an obviously prickly and longstanding issue which has clearly raised emotions for many years. I have learned a lot of details about ivy over recent weeks and I admit this is a short time. But key people provide real facts. Let’s keep this cool and talk respectfully on this forum. I am sure this is what the administration would prefer. I am reluctant to give up on you on this forum as some of the contributors have delivered sound and relevant information. Thanks to all of you.

Why so touchy about this? Not everyone thinks like you my friend. How much do you know about genetics and ecology? You sound like you know everything about forestry and simply don’t like someone outside the field asking a few different questions. If you can’t be constructive you should back off and let others speak.

Hi Paul. Great input thanks. I am having some difficulty differentiating fact from fiction or rather fact from supposition. Even woodlands trust replied with cut and paste from a post on this site Which itself referred to an original article published in 2000 by a commercial organisation involved in advising on tree husbandry. The problem is that as climate adjusts and husbandry methods change it can open the door to a step change in ecological response or in this case a potential opportunistic intrusive expansion of one species over its neighbours. I await a response from Forestry Commission to whether they accept this can happen. The standard definition of invasive is as a species introduced by humans from another country or domain. In the USA our native Hedera helix or English Ivy as they call it is classified as invasive for exactly the reasons I cite. Smothered ground cover and canopy. What happens there and here are driven by the plant behaviour which is the same in both countries. Opportunism. To control this requires firstly monitoring then analysis and finally a considered decision with practical advice and actions. I am at this point just collecting facts. As you suggest earlier images of that spinney would be helpful but in any case the ivy was not of course always like that by nature of the growth process. What part of Devon do you come from? I am from South Devon myself. Please respond and keep up the dialogue. It is very productive. Thanks. JC

I’ve done loads of google on this subject and a pattern emerges between emotive comments and hard factual objective material. Time has come for a mature objective discussion. Arborists and woodlands management will view it from a professional practical perspective but it will be based on personal day to day activities and this means contracted operations. I am really more concerned withe the wider picture and especially roadside and public paths and areas where there is a clear neglect of control over the very clear expansion of ivy encroachment to new zones and possibly much higher into the unmanaged canopy. I am hoping to define this level of encroachment from the experience of arborists and others who have a mature and objective attitude towards discussion. Thanks for your contribution. JC Here image of smothered woodlands locally

Excellent article in principle. However there is an additional aspect which increasingly demands attention. Either climatic or husbandry changes may be causing a slow but insidious expansion of ivy in the countryside in general and in the tree canopy in particular. This is potentially dangerous especially in locations close to country roads and habitation. Is anyone actually monitoring the general increase of high level ivy growth in vulnerable trees? It could be too late to react by the time this effect is officially recognised unless a competent agency puts effort into this issue as a matter of urgency.

We could have fun with this but let’s just say I accept your comments in good spirit. I am not an arborist. Does this mean I am dabbling in a forum that I should avoid? You sounded encouraging…

Thanks for your more educated comments. By the way…ducks don’t swim🤣🤣🤣

Steady on there. I am not alone in my opinion of ivy needing considered and proportionate control. I understand and respect that you have a different opinion. You have a right to that as we all do. But unhinged???

Yes. Misread or rather I was not clear. Sorry. If ivy is allowed to go rampant then like any other invasive species it can cause major disruption to the stability of its local ecology. Not environment. That’s what I am concerned about. Thanks

Absolutely not. As the tree is seemingly strong and surviving and not posing a threat as it’s in woodland then I would leave well alone and cite it as a special case. I am not one of you arborists. I am a retired scientist with an amateur and increasing interest in ivy and its potential threat to the environment. Thanks.

I find the link here which helps understand the growth habits of ivies etc. Really worth a read. https://www.thefreelibrary.com/Heteroblasty--a+review.-a0259155098 Here are two images of the same tree. Any ideas how old this ivy is? In this case it has clearly not killed the tree but there are so many examples that act as sails on more vulnerable slender trees. This is when there is a clear and present danger from falling trees. Can you really say there is no problem with ivy??? By the way. I now believe the two leaf types are from the same plant in most cases where both apparently exist on the same tree. And in the uk probably Hedera helix. Please correct me if you are absolutely certain of your facts. Thanks

https://www.thefreelibrary.com/Heteroblasty--a+review.-a0259155098 Sent from my iPhone

Thanks to Peasgood. Your school teacher has been shown to be quite correct and for that I am also grateful. I have found a really good 2011 review on “heteroblasty”. This is the scientific term for changing leaf (and other) plant forms/size as the plant develops from juvenile to adult/reproductive stages. It explains everything regarding ivy and my specific concerns. Ot also suggests the reason for possible environmental or climate driven expansion of vegetative adult ivy/liana species here in the uk. The woodland and countryside community could be encouraged to check this out with regard to the potential observable changes occurring to trees and hedgerows as I have described. https://www.thefreelibrary.com/Heteroblasty--a+review.-a0259155098 Sent from miPhon Heteroblasty--a review. - Free Online Library WWW.THEFREELIBRARY.COM Free Online Library: Heteroblasty--a review.(Report) by "The Botanical Review"; Biological sciences... Quotation therefrom: While tree saplings invest in own stem and branches, "juveniles" of climbing plants depend on structural support from other plants for further access to the canopy. Contact can be achieved by skototropism, i.e. growth towards the shade (Strong & Ray, 1975). Once a trunk is reached, there is a switch to positively phototropic growth. This phenomenon is little studied, but suggests a change in tropic response during ontogeny in addition to any morphological variation. Elsewhere it describes drivers including ecological and potentially environmental pressures which of course can trigger wholesale changes to the growth profile of a species across a large geographical area. Thanks to all for enabling me to find this informative document which is so relevant to the ivy issue.

Thanks to all contributors here. I am simply trying to find out some facts about ivy as an interested older person who has noticed the apparent rather extreme growth of ivy in our countryside trees and hedgerows. It was not like this only a few years ago and now whole copses are smothered in ivy. In my ignorance I considered it could be an invasive species such as Hedera canariensis. My identification app SEEK suggests this. But on further investigation it is more likely the leaf variant of Helix. So thats ok for an identification. But it doesn’t change the fact that there still appears to be a recent huge appearance of overloaded trees and hedgerows locally in Cambridge area. It may extend mich further and certainly includes Suffolk and Norfolk. Possibly countrywide. If so we need to know. I know more now ivy having read your various comments. Thanks.

Thanks. Its not so much a panic…more of an alert and a call to arms as this is most certainly a developing potential menace to our ecologically stable countryside.

Thanks. You’re right. I can’t stop climate change. But if enough people recognise the issues raised by uncontrolled ivy invasion then together those in the industry can start to take responsible remedial action to lessen the impact and retain some semblance of control over this encroachment by ivy. I suspect it is going unnoticed at the moment or at least the risks are not fully recognised. Even by those in authority over our countryside and woodlands. I am talking to them independently but its not a comfortable subject for them for some reason.