Roadside tree management in Hong Kong

Abstract

New roads are built in Hong Kong every now and then. With the Greening Master Plan (GMP) implemented in Hong Kong, a new roadside landscape was made from the up-to-date planting practices. A roadside tree survey with 533 trees represented by 28 tree species in 16 botanical families was conducted in both newly built roads and existing roads under the urban areas implemented with GMP for comparisons of tree growth space, tree species diversity and tree condition. Tree growth spaces in newly built roads were more spacious with wider adaptation with tree strip as type of growth space than those of existing roads. 58.41% of the trees surveyed in newly built roads were native species compared with 13.48% in the existing roads. The tree condition analysis casted aglance at the overall tree condition as well as the individual tree part conditions in crown, trunk, branch and root. For all trees surveyed, most defects were found in branch. Waterspout being the most frequent defects found in 58.72% of the trees surveyed and dead tree branches being the second frequent defects found in 42.21% of the trees surveyed. With the comparison of tree data collected in the tree surveys in the past, species like Chukrasia tabularis, Koelreuteria bipinnataand Elaeocarpus apiculatus were more widely adapted nowadays. Individual tree species performance and trees performance according to the type of roads were also included in the tree condition analysis. In general, the tree family Arecaceae obtained the highest overall condition scores while the tree family Moraceae obtained the lowest. Trees in the newly built roads obtained higher condition score in crown, branch and root than the existing roads but lower score in trunk. From the result of the tree survey concerning the planter width in the newly built roads, most of the trees fulfilled the existing requirement. It revealed that Hong Kong SAR Government has paid close attention to the tree growth space to promote tree condition.