This study will seek to understand effects of bracken control treatments on subsequent vegetation development. The project will build on current long-term experiments examining bracken control and vegetation restoration, remedial treatment and control of bracken front spread and will apply follow up treatments to the existing programme of measurements. A number of sites in the Chronosequence Survey (carried out in 1994—1995) will be re-visited in order to verify trends, validate survey methods and calibrate model time scales. A series of additional sites will be surveyed in order to provide a test data set for existing models. In addition, a further group of sites will be monitored prior to spraying and then followed up annually for the duration of the project. Predictive models relating to major vegetation classes will then be developed using both experimental data and information obtained from the survey work. Moreover, existing models for bracken growth and vegetation development (BRACON and REBRA) will be further validated and re-parameterized following a complete analysis of experimental and survey data. Results will be used to reissue guidelines on bracken control and vegetation restoration.