Many thanks for the information. I'm afraid my knowledge of the detail you provide is quite limited. I'll stick to natural=row_of_trees. As you suggest it is likely to require the way to be marked on both sides. I hadn't thought about using scrub on a way. For some reason the JOSM preset is restricted to an area but it seems you can directly tag a way as scrub.
Regards Dudley Date: Thu, 29 Aug 2013 06:30:23 +0100 Subject: Re: [Talk-GB] "Lines of Trees" along river banks etc. From: sk53....@gmail.com To: dudleyibb...@hotmail.com CC: talk-gb@openstreetmap.org I don't think these are hedgerows at all. They are really relict river gallery woodland (usually Salicion albae, NVC W6) and I would expect are mainly Willows with the odd Poplar and Alder. A photo example (and a location) might help. Typical components along the Trent (Notts & Derbys) and Thames (Berks & Bucks) will be: planted trees, usually hybrid Poplar and White Willow, but some real oddities Crack Willow and Alder as standard trees pollarded trees, mainly Crack Willowshrubby trees, predominantly Osier and Grey Willow, but some Almond & Purple Willow occasionally dense scrub with Hawthorn and Elder The willows nearly always are self-set. Any willow twig broken off in a flood is capable of regenerating (for Crack Willow and Native Black Poplar this is the usual means of propagation), provided there is enough moisture. This means that river banks are naturally always getting new additions, and that clearance of willow scrub is a never ending task. However, the zone where this happens is quite narrow, depending of height of flood waters and maintaining the relevant moisture levels. I don't know much about palatability of willows to livestock, but suspect they are not very tasty. When fields have grazing next to a river, usually cattle will have made a few gaps to get at the water, but my impression is that they don't graze on willows, although sheep probably do. It may be useful to show that a water body is tree-lined. I personally use tree_lined=yes on tree-lined roads (more as a place holder), but there is also natural=row_of_trees. You might want left and right. For the scrub willow thickets I think natural=scrub is the right tag, even if you choose to put it on a way (these will be NVC W1-W3, with W1 being the commonest). Regards, Jerry On Wed, Aug 28, 2013 at 11:15 PM, Dudley Ibbett <dudleyibb...@hotmail.com> wrote: Hi I was wondering if anyone has been mapping these? Quite often I come across streams and rivers where there are dense lines of trees along the river banks. Occasional I find lines of trees which seem to be remnant hedgerows where the shrubs have been removed. Looking on line it would seem that these are a hedgerow type. http://www.hedgelink.org.uk/images/bap/key%20to%20hedgerow%20types%20bigger.jpg https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/69285/pb11951-hedgerow-survey-handbook-070314.pdf This would perhaps suggest they should be marked as ways with barrier=hedge and hedge=line_of_trees or perhaps just the latter. An alternative might be to use natural=tree_row which is defined in the wiki but the examples seem more to related to trees that have been planted at regular intervals and where there isn't generally an overlap in the canopy. I have used this a few times but I'm not convinced it is the right way to tag this feature given that it seems they are a type of hedgerow. This may be something for the tagging email group but these a quite common features in the UK so I thought it would be good to ask here first. Many Thanks Dudley _______________________________________________ Talk-GB mailing list Talk-GB@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk-gb
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