Species diversity and spatial differentiation of old-valuable trees in urban Hong Kong

Document Type

Journal Article

Publication Date

2013

Keywords

Floristic diversity, Heritage trees, Tree conservation, Unique species, Urban trees

DOI

10.1016/j.ufug.2013.02.001

Abstract

Heritage trees play special ecological, historical and landscape roles in cities. The officially designated old-valuable trees (OVTs) in Hong Kong, threatened by urban intensification and improper care, demand deep understanding to inform management and conservation. This study evaluated their floristic diversity, biomass structure and importance value, and spatial pattern and differentiation by districts and tree-habitats. Data analysis was assisted by detrended correspondence analysis (DCA), similarity percentage analysis (SIMPER) and other statistical tests. New indices, namely district dissimilarity index (DDI), district heterogeneity index (DHI), habitat dissimilarity index (HDI) and habitat heterogeneity index (HHI) helped to assess spatial differentiation. The 352 OVTs belonged to 70 species, 56 genera and 36 families. Ficus microcarpa dominated with maximum importance value, accompanied by only three common species. Some 22 rare and 44 solitary species denote diverse origins due to inheritance and cultivation. Moraceae and Ficus were the dominant family and genus. The oldest districts accommodated more species, trees, and unique species, whereas newer districts had notably less. DCA showed higher floristic fidelity in old districts, and three common Ficus species were ubiquitous in districts. SIMPER results showed the highest DDI and lowest DHI in the newer district. Public park and garden (PPG) habitat harbours most species, trees, and botanical uniqueness. Three Ficus species were also ubiquitous in habitats. Public housing and PPG had the highest HDI. District and habitat dissimilarities were mainly contributed by dominant and common species. Management implications with reference to preservation and enhancement of OVTs were explored, with applications for other cities.

Source Publication

Urban Forestry & Urban Greening

Volume Number

12

Issue Number

2

ISSN

1618-8667

First Page

171

Last Page

182

This document is currently not available here.

Link to Publisher’s Version

Share

COinS