Baseline Vegetation data from the UK Environmental Change Network (ECN) terrestrial sites. These data are collected at all of ECN's terrestrial sites using a standard protocol (see supporting documentation). This was a one-off whole site baseline vegetation survey (though given the intensive nature of this survey, some sites did it over successive years) to generate a vegetation map and identify the areas within the site to be monitored. In this protocol up to 500 systemic 2m x 2m plots were surveyed and species presence recorded. ECN is the UK's long-term environmental monitoring programme. It is a multi-agency programme sponsored by a consortium of fourteen government departments and agencies. These organisations contribute to the programme through funding either site monitoring and/or network co-ordination activities. These organisations are: Agri-Food and Biosciences Institute, Biotechnology and Biological Sciences Research Council, Cyfoeth Naturiol Cymru - Natural Resources Wales, Defence Science & Technology Laboratory, Department for Environment, Food and Rural Affairs, Environment Agency, Forestry Commission, Llywodraeth Cymru - Welsh Government, Natural England, Natural Environment Research Council, Northern Ireland Environment Agency, Scottish Environment Protection Agency, Scottish Government and Scottish Natural Heritage. Full details about this dataset can be found at https://doi.org/10.5285/a7b49ac1-24f5-406e-ac8f-3d05fb583e3b