作者: Svein Solberg , Lars Strand
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摘要: This study aims to evaluate the quality of crown density data, based on independent, pairwise tree assessments. The data originates from monitoring forest health (crown condition) in Norway; 250 plots, comprising 12 000 individual trees Norway spruce, have been reassessed by a single observer during 1990–95. Of trees, 2300 were controlled more than twice, providing possibility evaluating assessed temporal changes density. True errors (standard deviation) are estimated be about 10% for and 5% plot means, while real standard deviation differences slightly higher. similar magnitude. Systematic found between sites types, partly resulting bias. However, results suggest that bias is really result each observer's personal style assessment.