Urban greeneries' impact on health status of small-leaved lime (Tilia cordata Mill.) in South Lithuania

Abstract

Small-leaved lime (Tilia cordata Mill.) is the dominant tree species in urban plantings throughout Lithuania. During 2009-2013, several sanitary parameters of the state of small-leaved lime, namely defoliation, leaf deformation, necrosis, drying branches in tree crown, diseases intensity, pest abundance and average damage were evaluated in the urban spaces of southern Lithuania. Lime sanitary state was better in recreational greeneries than in street plantations due to worse edaphic and microclimate conditions, and particularly low soil humidity there. Dry and light soils in the drought period of the 2009 summer induced the highest dechromation (1.01 ± 0.08) and defoliation (1.26±0.2) of premature leaves. The warm summer of 2013 without heavy rain was favourable for the spread of aphids (average damage 2.83 ± 0.03), and later for the settling of the pathogen fungus Apiosporium piniphilum (average damage 5 ± 0.28). The average damage of leaf spots pathogen (agents Mycosphaerella microsora, Apiognomonia errabunda) was 1.86 ± 0.05. Leaf spots (Mycosphaerella microsora) prevailed in recreational green areas (1,01± 0,57 iki 3,0 ± 0,08) and therefore might be selected as an indicator of clean air. The sufficient values of both precipitation and temperature fostered the spread of this disease during 2010-2011 across all green area types. Small-leaved lime was relatively healthy in recreational green areas during 2009-2013, i.e. defoliation, leaf necrosis, the drying branches in the crown were evaluated by one point. Only cutting grass may have injured young tree trunks. Consequently, this species could be preferred for urban greening in southern Lithuania.