Roofs & Rambles

A visit to Pestival at the weekend inspired me to write something on habitat walls, sand walls and of course green roofs! Nearly everywhere I have traveled in Switzerland and Germany, from the Black Forest to thuringia, to the high Alps, to animal parks, nature reserves and even Universities I have always encountered these features. And I have always been struck how you rarely you see them in the UK!

Okowerk, which is a fantastic environmental education centre in the Grunwald just outside Berlin has numerous sand walls. The main building has one of the oldest green roofs in Germany and it is covered with lichen found nowhere elsewhere in Germany. The roof was originally covered in sand to protect the wet bitumen waterproofing from fire. The air quality in the Grunwald being much better than in the city meant that the roof was colonised by a whole range species other than sedums. Now an ecology centre at ground level there all sorts of things happening to promote ecology and in particular invertebrate ecology. There must be at least 10 sand walls, some of which also have green roofs. This interconnectedness of habitat at roof ground and wall is really inspiring. And I like the rustic look of the sand walls. I was told when there that many of the walls had been constructed by local children. Sand was mix with water and a little fixing agent and then the kids had to make wet balls of sand that were then piled up on one another. Sort of hting kids would love! Another wall is a combination so of logs embedded in sand aloowing wood burrowing and sand burrowing bees to live side by side.

We have also managed to get a small project going with miniature sand walls on green roofs. This is a London Wildlife Trust Project funded by Sita Nature Enhanced. the promotion of green roofs, brown roofs and living roofs in London had been driven in the main by an interest in biodviersity on green roofs. During research on invertebrates and green roofs we became interested in how we could perhaps enhance simple sedum roofs by providing some substrate for species to nest in. Simply sedum roofs are all well and good but some of the really interesting bees etc need something to nest in and not just flowers to feed on. The sand walls are on six roofs scattered across London.  And mining bees are using them. A simple but important addition to a green roof.

This summer John Little of the grassroof company and I were funded by Buglife to install a brown roof for rare bugs at the new Wat Tyler Centre in Pitsea, Essex. This centre is surrounded by some of the most important habitit in the UK for bees such as Bombus humilis and Bombus sylvarum. The substrates used will hopefully find these bees nesting in the near future. however we also had the chance to create lots of different habitat features including log piles and habitat walls. Once we have seeded and plugged the roof with wildflowers in the next few weeks the roof will be an exemplar to how to green at roof both BUGS and climate change!

I have stolen a couple of screen grabs from Mark Ecclestone’s excellent site. He is often building habitat walls with green roofs and his green roof on his shed will feature in our forthcoming bok with John Little, Nigel Dunnett and Ed Snodgrass – small scale green roofs. he has been building the habitat piles for a number of years up in Shropshire and I would definitely check out his blog. And his great pictures.

Another blog I shall mention is Damian’s at HelpSaveBees. I was pleased to meet him the other day at the Pestival and hopefully we will be doing some stuff together. Perhaps even build a habitat wall on a green roof! That’ll be fun.