Towards the harmonization between National Forest Inventory and Forest Condition Monitoring. Consistency of plot allocation and effect of tree selection methods on sample statistics in Italy.

In the frame of a process aiming at harmonizing National Forest Inventory (NFI) and ICP Forests Level I Forest Condition Monitoring (FCM) in Italy, we investigated (a) the long-term consistency between FCM sample points (a subsample of the first NFI, 1985, NFI_1) and recent forest area estimates (after the second NFI, 2005, NFI_2) and (b) the effect of tree selection method (tree-based or plot-based) on sample composition and defoliation statistics. The two investigations were carried out on 261 and 252 FCM sites, respectively. Results show that some individual forest categories (larch and stone pine, Norway spruce, other coniferous, beech, temperate oaks and cork oak forests) are over-represented and others (hornbeam and hophornbeam, other deciduous broadleaved and holm oak forests) are under-represented in the FCM sample.

Quality Assurance and measurement errors in monitoring tree crown conditions in Italy.

The adoption of a comprehensive Quality Assurance (QA) programme for tree condition monitoring resulted in a rapid and steady improvement of data consistency in crown transparency assessment. On the other hand, the assessment of damage due to insects and fungi remains problematic and requires further training and control efforts. While our findings demonstrated the benefits arising from a QA programme and even the need to reinforce it, recent financial constrains have resulted in a severe reduction of the field checks.

Crown condition surveys in Italian forests: issues in reporting findings.

This study examines defoliation and discoloration findings collected throughout the Italian Level I network between 1997 and 2000. Prior to this period no Quality Assurance procedures had been implemented, so that earlier findings cannot be considered reliable. The aim of the study is to compare different indices used in reporting findings, in order to determine the full potential and limitations of each.