Perhaps the most significant result of GiGL’s work with the Greater London Authority (GLA) is our expansion from a traditional biodiversity records centre to one that handles a much wider suite of habitats and open space information. This is the result of a process started before the GLA existed.
A habitat survey methodology for London was first developed in the mid-eighties, when the Greater London Council commissioned London Wildlife Trust to complete the first comprehensive survey of wildlife habitats in Greater London.
An updated methodology was adopted by the London Mayor in his Biodiversity Strategy in 2002. This was further developed in 2004 to include open space typologies. Read more about the origins and evolution of this pioneering survey approach in this newsletter article.
The London Survey Method was used for a rolling programme of surveys, from the mid-eighties to 2009. The habitat survey data from that programme were collated by GiGL and formed the baseline of the habitat dataset for London.
The current GiGL habitat dataset is now inclusive of this London Survey Method data and other kinds of standard survey methodology, Extended Phase I and National Vegetation Classification, so it can be updated as new surveys are completed across London.
London Survey Methodology
The London Survey Method format is similar to an Extended Phase I survey and collects essentially the same ecological information, in the same detail. For this reason, you will see it referred to as Lon(P1).
Unlike Phase I, the London Survey Method is designed specifically for an urban setting using habitat classifications appropriate for London.
During the rolling habitat survey programme, an individual survey form and map was generated for each site, to reflect the fragmented nature of London’s green spaces, to standardise reporting and to aid comparison between sites.
Information was gathered for any open space larger than a quarter hectare. These units of land were referred to as “parcels” with several parcels comprising a “site”. Sites and parcels were all named and given unique references.
For most boroughs, habitat categories were recorded as an estimated percentage cover and equivalent area within the parcel. Where boroughs funded more detailed survey, a parcel represented a single habitat.
Open space information, such as access and facilities on site, were also comprehensively gathered as part of this survey from 2004 onwards.
The paper forms were digitised by GiGL. Each parcel boundary was mapped on a geographical information system and linked to its habitat and open space records.