Monumental trees in urban space – a case study of Lublin

摘要

Background. Venerable trees are an important element of urban green space, e.g. old trees in historic parks and gardens. The health of this group of trees, especially in cities, is problematic. The majority of old trees are protected by law, but not all of them are given care systematically. Active protection of monumental trees should be based on numerous analyses of habitat conditions and elimination of external threats. The aim of the study was to assess the conservation status of monumental trees growing in various public areas of Lublin. Material and methods. In 2014 38 trees ranked as natural monuments were inventoried. Indi­vidual specimens were measured biometrically. The health status of the trees was estimated with the scale developed by Kubacki and Zbroński (1989). The degree of soil hardening around the plants under study was the determinant of their state of preservation. Therefore, a grading scale was used, where 0 referred to an area of unpaved grass, while 4 referred to the most compacted area. Results and conclusions. In 2014 there were 38 natural monuments in the city: 29 individual specimens, 5 groups of 11 trees and 4 espaliers including 90 trees. The trees and shrubs were measured biometrically, their health was examined and the degree of soil hardening around them was assessed. There were 14 species, mostly: Tilia cordata Mill. (45% of the trees under study) and Quercus robur L. (32%). 7% were in good state and 72% were in average health condition, which was related with regular care treatments, typical of trees at this stage of senescence. 21% of the trees were in bad or very bad condition. As far as the degree of soil surface hardening around the trees is concerned, the research showed that the elimination of bioactive surface around the trees had negative influence on their condition.