First Report of Chalara fraxinea on Common Ash in Italy

In many European countries, the anamorphic Chalara fraxinea Kowalski (teleom. Hymenoscyphus albidus [Roberge ex Desm.] Phillips) is responsible for a severe and rapidly spreading dieback of Common ash (Fraxinus excelsior L.) since it was first reported in Poland. Recently, this disease was added to the EPPO Alert list and the NAPPO Phytosanitary Alert System. To our knowledge, this is the first report of C. fraxinea in Italy. Investigations on its presence in all Fraxinus species naturally growing both in the investigated area and in the nearest regions are in progress

Identifying treetops from aerial laser scanning data with particle swarming optimization

In this study, the particle swarming optimization procedure was applied to parametrize two Local Maxima (LM) algorithms in order to extract treetops from LiDAR-data in a test area (10 km2) of heterogeneous forest structures of conifers in the Alps. The obtained results were compared with those of a widely used variable-size window LM algorithm calibrated using literature values. Quantitative statistical parameters like matching, extraction, omission, and commission rates were calculated. The experimental results showed the effectiveness of the proposed method, which was capable to identify the 91% of the trees and estimate the 92% of the real above ground biomass with a total extraction rate close to 1. Almost all the dominant and codominant trees were extracted, while the extraction rate of the dominated trees averaged over 50