Many arboriculturalists and architects use the KeyTREE utility (from Transoft Solutions) for plotting tree survey data onto AutoCAD drawings.
OTISS is an excellant data collection system that can be used on-site to gather and collate the survey data. OTISS can then generate a KML formatted file that can be imported into KeyTREE. This makes it seamless to use OTISS for BS5837 data collection and KeyTREE for preparing your CAD drawings.