Quality Assurance for Crown Condition Assessment in Europe : Final Report

2002

111 S.

Bandaufführung

95228

Quality Assurance for Crown Condition Assessment in Europe. Quality Assurance (QA) and Quality Control (QC) are increasingly important in environmental monitoring programs. They help in documenting methods (and changes in methods) and the interpretation of data. To collect information about QA/QC procedures adopted for crown condition assessment in Europe, an extensive questionnaire (96 questions) was designed and distributed by the end of the year 2000. The questions cover various factes of QA procedures, including the design of the crown condition surveys. Twenty-two NFCs from 22 countries plus 4 German länders have returned the questionnaire and their answers form the basis of the present report. The questionnaire concerns both Level I and Level II monitoring, and data were processed separately. However, with the exception of some "structural" aspects (e.g. sampling design) which are different by definition, the results of the questionnaire are simular for both Level I and II. As far as the documentation is concerned, the results of the questionnaire revealed that much work has been done in Europe and that the data quality at national level is actually known, although little effort was placed up to date to process data in an harmonized way at European level. The degree of comparability between the countries that returned the questionnaire revealed several source of potential inconsistency. These sources are obvious when examining the data about the setup of the monitoring system and the methods adopted for the assessment. The differences in the setup of Level I probably comes from the fact that the network is based on existing monitoring and inventorying systems, which were based on different target population. On the other hand, for Level II there are different models/hypothesis behind the selection of the monitoring plots. The methodological differences pointed out by the questionnaire should be examined in relation to the aims of Level I and II and in the light of data processing. In this perspective, while it is out of doubt that much work has been done in the field of QA/QC for crown condition assessment in Europe, the results suggest to make a step ahead - orient this work according to the needs placed by an international monitoring system.