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作者

Samuli Helama;Alar Läänelaid;Juha Raisio;Kristina Sohar;Antti Mäkelä

来源

URBAN FORESTRY & URBAN GREENING,Vol.53,Issue1,Article 126707

语言

英文

关键字

Urban trees;Tree growth;Dendrochronology;Stem eccentricity;Drought stress;Road de-icing

作者单位

Natural Resources Institute Finland, Ounasjoentie 6, 96200, Rovaniemi, Finland;Department of Geography, Institute of Ecology and Earth Sciences, University of Tartu, Vanemuise St. 46, 51014, Tartu, Estonia;City of Helsinki, Public Works Department, Helsinki, Finland;Finnish Meteorological Institute, Erik Palménin Aukio 1, 00560 Helsinki, Finland;Natural Resources Institute Finland, Ounasjoentie 6, 96200, Rovaniemi, Finland;Department of Geography, Institute of Ecology and Earth Sciences, University of Tartu, Vanemuise St. 46, 51014, Tartu, Estonia;City of Helsinki, Public Works Department, Helsinki, Finland;Finnish Meteorological Institute, Erik Palménin Aukio 1, 00560 Helsinki, Finland

摘要

Urban trees growing in roadside locations encounter stressful impacts in terms of atmospheric and soil conditions and mechanical damage. Here, a set of lime trees from a roadside location in Helsinki was analysed for their radial growth and tree-ring width variability in relation to climate records, effects from salt injury and mechanical damage the trees have experienced during their lifetime. Cross sections of the stems were found to be eccentric in shape, the maximum radius being commonly between NW and NE (the direction of the street), whereas the minimum radius was typically found towards W or E. The level of mechanical damage corresponded with the level of eccentricity expressed as the ratio between the longest and shortest radii. Growth rates approximated those of lime trees from parks in Tallinn (Estonia) but were markedly lower than those recorded previously from London (UK). The tree-ring chronology was correlated positively with the late-winter (February through March) temperature and early-summer (June) precipitation. The summer moisture signal was found to enhance over the recent decades, which likely indicates increased vulnerability to droughts and water scarcity. In addition to climatic events, the yearly amounts of road salting were negatively correlated with tree-ring anomalies. This evidence demonstrates the multiple stressors to the trees in urban roadside locations guiding their management options and shows the potential of Tilia to become a major tree genus for urban dendrochronological studies.