Dr Angie Ng is currently the Conservation Manager of the Conservancy Association, taking responsibilities of various nature conservation and research projects. Dr Ng is more than a plant lover. She was devoted to studying Hong Kong native plants for forest restoration in her PhD study of plant ecology in the University of Hong Kong. In the past decade, with her rich knowledge on local plants and ecology, Dr Ng conducted various application and promotion works on HK native plants, hoping that the general public and other professionals could have better understanding on the diverse array of HK plants and their proper application.

Abstract

Study on Native Plants for Enhancing Biodiversity of Rivers in the City

A river or a channel? An important determinant, from both the views of human perception and ecological functionality, is the presence of good vegetation which forms the foundation to an ecological habitat. In the rising trend of eco-greening of rivers in the city, the diverse array of Hong Kong native plants could make great contribution, not just to enrich the palette of plants for landscaping effects but also to form habitats to enhance ecological functions. Of the 2000 plus species of Hong Kong native plants, only a handful of them are actually applied in greening projects. Limited understanding coupled with limited seedling supply in market largely constraint the wide application of those native plants.

This study aimed to study growth performance of selected native plants in different settings of river environment and the results obtained could provide reference to future species selection and propagation. Low hydraulic resistance, low availability in market and potential ecological functions were key considerations in species selection in the study. 54 species of native small shrubs and herbs were collected and underwent propagation screening in DSD’s nursery at Siu Ho Wan. 34 of them were tested in various planting trials in two DSD river sites. In summary, early establishment of most species was satisfactory, however, the highly modified river environment with minimal maintenance effort and strong competition from invasive exotic weeds, posted great challenges to the long term survival and growth to most species. 11 species were identified to have wide adaption and good growth in most river environments.