Accessibility to urban green spaces: A critical review of WHO recommendations in the light of tree-covered areas assessment

Easy accessibility of Urban Green Spaces (UGSs) is essential to the quality of life in urban areas. The World Health Organization (WHO) recommendations focus on spatial access to UGSs, define as accessible those larger than 0.5 ha situated up to 300 m of residential areas, and disregard the social significance of smaller green spaces. This paper assesses the extent to which the WHO recommendations permit the identification of locations for tree-covered UGSs that serve urban residents. The study uses geo-questionnaire to collect data on residents’ perception of the ecosystem services (ESs) provided by trees in both small-sized (<0.5 ha) and larger (≥0.5 ha) UGSs in two Polish cities, Poznań and Gdańsk. Three factors impacting the social perception of UGS accessibility were controlled: (a) distance to trees (influencing reaching it by walk), (b) age, (c) the ESs provided by trees in both sizes of UGSs. The minority, i.e. 26 % of respondents valued trees in the larger UGSs.