the GiGLer

The newsletter of Greenspace Information of Greater London CIC

Suits you, Sir

Amanda MacLean, London Biodiversity Partnership


You’re a borough ecologist, and your dreams have just come true. £100,000 of Section 106 money has landed in your lap, courtesy of a major development. With that much money, you could create dozens of ponds, hectares of meadow, or plant up plenty of new woodland. But how do you decide what to do and where? The London Biodiversity Partnership’s Amanda MacLean may have the answer.

You’re a developer wanting to build a new shopping and housing complex on a piece of wasteland.You need to ensure that your development will result in a net gain for biodiversity. It’s a big development, so there is plenty of room for a wildlife area – but what should go in it?

You’re a council planner producing the spatial plans for your borough’s Local Development Framework.You know that your LDF should identify areas for the restoration or creation of new habitats – but which habitats, and where should they go? In the past, choices like these have largely been made on an ad hoc basis – on what ‘seems right’. Now, a new GiGL product will allow a much more rigorous approach, and will give the ecologist, the developer and the planner confidence that their decisions are based on the best available information. After a two-year incubation period, ‘habitat suitability maps’ are now available to GiGL partners and data users.

The maps show the open spaces in London where habitat creation would be of the greatest benefit to biodiversity – areas where existing habitat could be expanded without a negative impact on other important habitats. There are maps for each of nine of London’s priority habitats – those that are most under threat and in need of conservation effort, as identified in London’s Biodiversity Action Plan. The London Biodiversity Partnership sees the maps as a key tool to identify areas where our partners can focus their work efforts. This will give a head start to our partners in the London boroughs, and the London-wide habitat action plan (HAP) groups, in delivering on London’s targets to increase the extent of priority habitats.

LBP has been working with GiGL on the development of these maps for the last two years. For most of that time, they were called ‘opportunity maps’, so why the new identity? During a recent consultation with partner organisations, it became apparent that the name was causing a lot of confusion. Many of our partners could not see how some of the ’opportunity’ areas on the maps could ever present real opportunities on the ground. A reasonable objection when considering, for instance, how much real-life opportunity there is to turn a working cemetery into a floodplain grazing marsh. In fact, the maps identify areas that are ecologically suitable to support the habitat, no matter what the area’s current use.

Because they do not incorporate land use, it’s important that the maps are always used in conjunction with datasets on land use and other relevant factors, and GiGL will be happy to work on such refinements at the request of its SLA partners.

Developing the maps has been a complex process, with several cycles of criteria selection, number-crunching, and groundtruthing. The first stage of the process, habitat condition assessment, involved the HAP groups drawing up a suite of indicator species and habitat features that, when considered together, indicate habitat quality. For instance, salad burnet, orchids and kidney vetch are indicators of good quality chalk grassland habitat, and their presence increases the quality score. But, extensive coverage of forbs and sedges, as indicators of poor quality chalk grassland, result in a lower score. GiGL interrogated their extensive database using these criteria and produced draft maps of habitat quality, which the HAP groups checked against reality in a series of field visits.

After these visits, the maps were amended. The resulting maps show the location of poor quality habitat that could be restored, and areas where acceptable or good quality habitat might serve as a ’seed‘ for habitat creation.

Next, the HAP groups drew up a list of criteria to identify which of these locations were also suitable for the creation of new habitat. There had to be room for new habitat, without replacing other important habitats. And there also had to be suitable ecological conditions. Again, chalk grassland provides a straightforward example – it needs an underlying chalk geology, which places strict limitations on suitable locations.

Once the first drafts of the maps were drawn up, they were put out to consultation. First the HAP groups, and then the council officers belonging to the London Boroughs Biodiversity Forum, were asked to comment on how well the information on the maps tallied with their on-the-ground knowledge. There was a tremendous response from the biodiversity forum, with nearly two thirds of the boroughs sending in feedback.

We were delighted with the response for a number of reasons. First of all it was clear that the criteria we had used were broadly successful in identifying suitable areas, and only a few minor changes were needed to produce the final versions. This gives us confidence that the maps reflect conditions on the ground as accurately as they can – taking into account the limitations of the available data – and will be a robust and reliable tool for LBP and its partners. Secondly, the consultation raised some issues with the presentation and interpretation of the maps, which we were then able to improve. And finally, such an enthusiastic response suggests that the maps will be well used now that they are available. In the coming years, London’s biodiversity should be all the better for it.

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