This dataset contains vegetation survey data from an upland heath site in the Clocaenog Forest. This was done by pin point methodology, and data includes both pin hits as well as measurements converted into plant biomass (grammes per square metre). Vegetation was surveyed in the experimental plots at the Climoor site in 1998, 1999, 2000, 2002, 2003, 2007, 2008, 2009, 2010, 2011 and 2012. The vegetation at the site is a typical UK upland heathland, dominated by Calluna vulgaris, with Vaccinium myrtillus and Empetrum nigrum also being present in the vegetation understory. In each year, measurements were taken at a time period of maximum growth, which was late August/early September. Individual species can be examined, as well as the different components of the higher plants (i.e. leaf, stem, flower). Data was collected by CEH staff and PhD students trained in the use of the methods. Climoor is a climate change manipulation experiment that utilises automated roof technology to produce drought and warming experimental treatments that reflect climate change predictions for the next 20-30 years. Full details about this dataset can be found at https://doi.org/10.5285/5b39a644-d614-4f2b-8df6-202ed440b4ab