The attached data are derived from two vegetation surveys commissioned and held by Natural England.
Each row represents a quadrat sample.
In the CM data cover of each species was recorded as percent cover (%). 
In the EMBER data species cover was originally recorded using the DOMIN scale and this was transformed to percent cover (%) as presented here.
More information about the methods used to collect the data is available in the associated paper:  
Noble et al (in press, 2017) 'Prescribed burning, atmospheric pollution and grazing effects on peatland vegetation composition' Journal of Applied Ecology.