This polygon dataset provides results of grassland surveys undertaken in the Cairngorms National Park between 2020 and 2022 as part of a joint project delivered by NatureScot and the Cairngorms National Park Authority. The aim was to establish the location and extent of species-rich grassland (SRG) within enclosed (and formerly enclosed) farm land, up to a maximum altitudinal limit of 500 m, using a combination of remote sensing and targeted field survey. This dataset covers the Livet, Avon and Dee catchments.
Patches of unimproved/semi-improved grassland, down to 0.04 ha in size, were identified and delineated by analysing high-resolution aerial photography (involving image segmentation and subsequent classification of the output). This provided a search map of polygons to visit in the field, targeting survey effort towards the areas where species-rich grassland was most likely to occur.
The field survey was undertaken by contractors during July to September in 2020 and 2021, and July to October in 2022. For each polygon, grassland communities and their relative percentage cover were described using the National Vegetation Classification (NVC), and species-richness was assessed. Locations of any missed species-rich grassland, occurring outside the search map polygons, were captured in the field and added to the dataset.
When species-rich grassland was encountered, additional detailed attributes describing the quality and condition of these stands were collected in the CNPGrasslandMapping_2020to2022_SRGAttributes dataset which can be joined/related to this one using the POLY_ID / PARENT_POLY fields. Other notable habitats and plant species were captured in the CNPGrasslandMapping_2020to2022_TargetNotes dataset.
There are 4930 polygons in total, of which 1482 (30%) were found to contain at least some species-rich grassland. The principal species-rich grassland NVC types were: dry – acid (U1d, U4c, U5c), neutral (MG2, MG3, MG5), calcareous (CG2, CG7, CG10, CG11); wet – purple moor-grass & rush pasture (M23a, M25c), tall-herb fen meadow (M27, M28). Polygons containing species-rich grassland can be identified using the SRG_PRES (yes/no) field.
The dataset contains the following fields:
NVC_1 to NVC_6 – NVC communities recorded in the polygon;
COVER_1 to COVER_6 – relative percentage cover of each NVC community in the polygon;
COMMENT – specific notes about vegetation in the polygon;
SRG_PRES – presence of species-rich grassland in polygon (yes/no);
NVC_LIST – list of all NVC communities in polygon and proportion cover of mosaic components;
SRG_NVC – species-rich grassland NVC communities and proportion cover in the polygon;
SRG_COVER – total percentage cover of species-rich grassland in polygon;
POLY_HA – area of polygon (hectares);
SRG_HA – area of species-rich grassland in polygon (hectares);
SURV_YR – year of field survey;
SURV_DATE – date of field survey;
SURVEYOR – field surveyor;
CATCHMENT – river catchment area;
POLY_ID – unique polygon identifier.
Complete project metadata document on spatialdata.gov.scot