Resumen
(1) Biodiversity, sustainable development and nature conservation are fundamental issues nowadays. All companies, administrations, governments and international organisations take these issues into consideration. Sustainable forest management always requires a compromise between profitability and conservation and in this fragile equilibrium, forest certification plays a key scheme. This sustainable management is of great importance in the European Union (EU), with the Forest Stewardship Council playing a fundamental role in forest certification. This certification forms the basis of the ecosystem conservation and improvement strategy in Ence, Energía y Celulosa, the leading company dedicated to the production of eucalyptus in Spain; (2) A three-phase protocol (identification of High Conservation Values, assessment of conservation areas and monitoring program), has been developed, providing clear, objective criteria, particularly concerning FSC (Forest Stewardship Council) Principle 9, the primary goal being the development and application of these objective criteria in the Ence conservation areas in the province of Huelva (Spain). One of the main criteria for habitat classification was correspondence with the habitats listed in Annex I of the Habitats Directive. The compatibility between forest exploitation management and conservation proposed by the Natura 2000 network encouraged us to use this methodology for the identification, classification and assessment of High Conservation Values considered in FSC forest certification: Principle 9; (3) The study encompasses 183 forest management units covering 52,022 ha, with a total of 11,847.45 ha being identified as High Conservation Value Areas. Through the identification and assessment of the conservation areas, the described methodology played a crucial role in demonstrating the positive impact of Ence’s certified forest management on the conservation of biological diversity; (4) This study demonstrates that an objective and reliable identification, assessment and monitoring methodology, with a proven high degree of accuracy in the location and characterisation of interesting and representative habitats in the region, can be implemented. Due to its objectivity, this strategy can be easily applied to other European sustainable forest management sites and possibly to other countries outside the EU.