Summarised Botanical Value Map 2021 (England)

Under the Natural Capital and Ecosystem Assessment (NCEA) Pilot, Natural England and the Botanical Society of Britain and Ireland (BSBI) have been working in partnership to use BSBI's vast database of plant records to inform the evidence base for tree-planting activities. Poorly targeted tree planting risks damaging wildlife and carbon-rich habitats, therefore using these data we aim to ensure that areas of high conservation value are preserved in the landscape. The summarised botanical value map provides an easily interpretable output which categorises monads (1 x 1 km grid squares) as being of Low, Moderate or High botanical value according to the presence of Rare, Scarce and Threatened (RST) plant species and/or the proportion of Priority Habitat Positive Indicator (PHPI) species that were recorded within the 1 x 1 km grid square between 1970 and 2021. The PHPI species are a combination of BSBI axiophytes, positive indicators for common standards monitoring and ancient woodland indicators. The dataset includes an overall botanical value, as well as values based on only the presence of RST plant species, and a value for each broad habitat type based on the PHPI species records. By viewing the different attributes, you can gain insights into how valuable a monad is for different habitat types and for plant species of conservation concern, as well as an indication of how well a particular monad has been surveyed. The categories of 'No indicators, poor survey coverage' and 'No indicators, good survey coverage' indicate where no indicator species have been recorded and survey coverage either is above or below a threshold of 3 'recorder days'. A 'recorder day' is defined as being when 40 or more species have been recorded on a single visit and 3 recorder days is assumed sufficient to achieve good survey coverage within a 1 x 1 km grid square. This map is not intended to be used to carry out detailed assessments of individual site suitability for tree planting, for which the RST plant species heatmap at 100 x 100 m resolution and the PHPI heatmaps at 1 x 1 km resolution have been developed by BSBI and Natural England. However, the summarised botanical value map can provide useful insights at a strategic landscape scale, to highlight monads of high value for vascular plants and inform spatial planning and prioritisation, and other land management decision-making. These should be used alongside other environmental datasets and local knowledge to ensure decisions are supported by the appropriate evidence. Please get in contact if you have any queries about the data or appropriate uses at [botanicalheatmaps@naturalengland.org.uk]. Process Description: The main data sources were the botanical heatmaps which were developed as part of the NCEA pilot in collaboration with BSBI. BSBI provided summarised counts of Rare, Scarce and Threatened (RST) plant species and Priority Habitat Positive Indicators (PHPIs) present within each 1 x 1 km grid square (monads) between 1970 and 2021, which were then further processed by an automated workflow to subset to England and gap-fill where values were missing, taking into account the influence of survey coverage. To create the summarised botanical value map these heatmap data were then further categorised based on the number of RST plant species or PHPI species present indicating semi-natural habitat of high quality. The number of PHPIs present per monad within each broad habitat heatmap were compared to the total number of PHPIs present within their surrounding area We used a local benchmarking approach to categorise monads based on the proportion of the total PHPIs recorded in the monad. If a monad contained less than 10% of the regional species pool this was deemed as being Poor value, between 10-20% was defined as Moderate value and over 20% was High botanical value, from a vascular plant perspective. Where a monad had no indicator records and survey coverage was poor, it was classified as ‘no indicators, poor survey coverage’. Datasets used: BSBI botanical heatmap data - BSBI OS Grids - OS ONS Country boundaries - ONS Common Standards Monitoring guidance - JNCC 2004 BSBI's Axiophyte list - Walker 2018 Ancient Woodland Indicators - Glaves et al. 2009 Plantatt - Hill et al. 2004 Further information can be found in the technical report at: [Botanical Heatmaps and the Botanical Value Map: Technical Report (NERR110)] Full metadata can be viewed on [data.gov.uk].