Implementation of quality assurance procedures in the Italian programs of forest condition monitoring

In 1996 the assessment of tree condition in Italy was subjected to a Quality Assurance (QA) program. The QA program consisted in (i) the adoption of Standard Operating Procedures (SOPs), the set of Measurement Quality Objectives (MQOs) expressed by Data Quality Limits (DQLs), (iii) a national training and intercalibration course, and (iv) field checks, performed on a number of areas spread over the country. In general, DQLs were achieved for a number of tree condition indices. However, problems were identified with crown transparency, the most used index in the international reports. Additional problems arose when considering the data quality at plot level as a result of the combined achievement of DQLs for the different tree condition indices.