City Trees

TREES OVER TIME: Self-Repair, Failure and Death Having children (in my case, five kids), it can be sur- prising how your time just disappears on the daily and weekly tasks involved with caring for them—and you soon feel like your children are growing up fast. Of course, they are only growing up as fast as anyone else's kids but it does feel like the hands on the clock dial are spinning at a giddying speed. The trick is to capture those days—on camera, on video—so you can reflect that you were there, that your kids were once gurgling babies and so you have a better rec- ollection of the efforts you put in to raise them. I suspect nearly all parents have a good collection of photos of their children at different stages of their development and of key moments and events in their early years. My photo album, however, is probably more eccentric than most, as I've had to make room for about 60,000 digital images of trees and associ- ated features (especially the fruiting bodies of fungi). When I took on my teaching role at Myerscough College in the spring of 2006, I bought myself a digital camera in order to record tree species, defects in trees, and many other things to serve as teaching aids. There is a massive benefit, as a lecturer, to be able to use your own images in the classroom, as you then have a depth of knowl- edge about what is being shown, the "where and when" of the image, and you can answer most of the students' queries more readily. Only recently did I realise (and then unlock) the real potential of this large collection of tree-related images. As it is now 2019, I can go back to the trees, defects, and fungi that I took a picture of previously and see what has changed by taking a current day image. I have collected over four hundred of these images in a self-driven project I am calling "Trees over Time." Compared to the original images, which were static, viewing the changes of these trees over a period of one year to over a decade is proving to be a much more valuable learning experi- ence for my students. To be honest, I am also learning a great deal from revisiting these trees, and there are often unex- pected outcomes. For example, I have captured the fusion of two stems in a horse chestnut (Aesculus spp.) that happened over ten years; I do not think that any arborist would have predicted the radical change in form that this young tree underwent. That's enough of an introduction, I hope, so you have the context for the following images, which I have given long descriptive captions to. I have selected eight images from my Trees over Time (TOT) project that relate to self-repair, tree failure, and tree death, just to give you a flavour of what this project is achieving. As well as appearing in a number of magazine articles, I hope to produce sufficient numbers of these sequence images to put together a book, with the particular aim to get my young students to start to see the world in the time-scale of trees' lives. Understanding how trees change over time is a key learning area, I think, to provide those trees with the right care. References Dunster J, Smiley E T, Matheny N & Lilly S (2017) Tree Risk Assessment Manual; 2nd Edition; pub- lished by the International Society of Arboriculture. Slater D (2016) Assessment of Tree Forks; Course notes available from the Arboricultural Association, UK. 32 CityTREES By Dr. Duncan Slater, Senior Lecturer in Arboriculture, Myerscough College, Lancashire, England

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