Sunday, 9 December 2012

Rustyback in Sheffield

After recently noticing a single clump of the rare wall-inhabiting fern Rustyback (Asplenium ceterach) by the entrance to Walkley Library, I was alerted to the fact that the nearby gennel connecting Walkley Road to Parsonage Street held a very sizeable population, estimated to hold more than 80 plants. Since then I have found two more very small populations of Rustyback in Walkley, one at the corner of Greenhow and Camm Streets, and one plant in another gennel connecting Fern Road to Walkley Bank Road. It seems likely that the large 80+ population is acting as a source for these three more recent colonisations.
Rustyback is only known from a handful of sites in the Sheffield conurbation, including a good population on the wall next to the entrance of Norfolk Park on Norfolk Park Road, so its pleasing to see that it is apparently spreading, and highlights the especial importance of protecting sites with large populations that can act as sources for the colonisation of new territory. Ferns on walls are great for winter identification, and a good key is available freely at
Don’t forget that photos of wall ferns uploaded to the Sorby Flora flickr group ( will also contribute to an updated Sheffield Flora.

Rustyback (Asplenium ceterach) at Walkley Library, Sheffield

Thursday, 6 December 2012

Sheffield's Ancient Woodland and SSSIs: Open data

Here are some data I retrieved a couple of years ago from the UK government's MAGIC site. Unfortunately, this site only provides downloads in proprietary GIS formats, ArcGIS and MapInfo I think. Given that the government's recent open data initiative is encouraging people to use public data in new ways, I guess it's ok to change the data into formats that make it more usable for the average person.

The files from MAGIC were edited in QGIS (a miracle of open source programming) to restrict the data to the Sheffield area. (EDIT: I should point out that this means the data are arbitrarily cropped to particular OS gridlines. This was done to reduce the file size for posting to the internet. If your local wood is not shown as 'ancient', it may simply be outside of the area that I cropped to. As I say above, the full national dataset is available through the MAGIC link above).

Then I followed the protocol that I posted earlier to turn them into KMZ files. So, the first map is Ancient Woodland, the second is Sites of Special Scientific Interest. The data can be downloaded for home use in Google Earth here and here, for the moment at least. Clicking the 'View larger map' link below each map will link-out to Google Maps, where, at least for the woodland dataset, the names of each land parcel are shown. [Also, choose the 'View larger map' link if the sites (which should be in red) do not appear automatically -- sometimes the site outlines do not seem to be retrieved from the hosting website.] Alternatively, if you zoom in on the map below and click on a woodland boundary, the name will be displayed. Obviously the original data are from MAGIC, and users should take heed of the license agreements imposed by the government, which restricts usage to non-commercial activities.

Ancient Woodland in the Sheffield Area

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SSSIs in the Sheffield Area

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