Decay characteristics of hazardous Tilia, Betula, and Acer trees felled by municipal urban tree managers in the Helsinki City Area
| Autor: | M. Terho, A.-M. Hallaksela |
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| Rok vydání: | 2008 |
| Předmět: | |
| Zdroj: | Forestry. 81:151-159 |
| ISSN: | 1464-3626 0015-752X |
| DOI: | 10.1093/forestry/cpn002 |
| Popis: | Summary In order to improve the management and protection of old urban trees, the decay characteristics of trees that had been removed as hazardous according to the local management protocol were investigated. The stage and the cross-sectional extent of decay were examined on a total of 181 park and street trees in the Helsinki city area: 64 trees of Tilia spp., 58 Betula spp. and 59 Acer spp. For Tilia , hollowed heartwood with low fungal expression and advanced decay caused by Ganoderma lipsiense were the two most common characteristics of cross-section samples from the points where stem breakage was most likely. For Betula , the primary reason for tree removal was usually lowered amenity value in terms of a declined appearance of the crown. Advanced decay, mainly caused by Inonotus obliquus , Piptoporus betulinus and Cerrena unicolor , were the most potential causes for stem breakage on Betula . For Acer , internal cracks, most often due to weak fork formation, were common causes of potential hazard. Decay caused by Rigidoporus populinus often increased the risk of stem breakage of these trees. In addition, advanced decay caused by Phellinus igniarius and Kretzschmaria deusta were the most important reasons for decreased safety of Acer trees. |
| Databáze: | OpenAIRE |
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