A Spatial Analysis of the Terrestrial Biodiversity of Hong Kong

This dissertation, "A Spatial Analysis of the Terrestrial Biodiversity of Hong Kong" by Yin, Yip, 葉彥, was obtained from The University of Hong Kong (Pokfulam, Hong Kong) and is being sold pursuant to Creative Commons: Attribution 3.0 Hong Kong License. The content of this dissertation has not been altered in any way. We have altered the formatting in order to facilitate the ease of printing and reading of the dissertation. All rights not granted by the above license are retained by the author. Abstract: Abstract of thesis entitled 'A SPATIAL ANALYSIS OF THE TERRESTRIAL BIODIVERSITY OF HONG KONG' Submitted by YIP Yin for the degree of Doctor of Philosophy at The University of Hong Kong in June 2002 A territorial evaluation of the effectiveness of the current protected areas in representing biodiversity in Hong Kong SAR, China, was conducted, and additional sites for protection identified. The present study also investigated two techniques to overcome the problem of data deficiency: biodiversity indicator and predictive models of species distribution patterns. To facilitate spatial analysis, the study made use of Geographical Information Systems (GIS) for data extraction, overlay and output. Compiled data on amphibians, reptiles, mammals, breeding birds, dragonflies, butterflies, ants and rare vascular plants were used unless stated otherwise. Although 38% of the total land area (1098 km2) of Hong Kong is protected, over half of the 623 globally, regionally or locally restricted species were under-represented in existing protected areas, with ants, butterflies and reptiles most poorly represented. The hotspots (1 km grid squares with species richness recorded within the highest 10% for a particular taxon group) of different taxa also received differing levels of protection. To identify additional sites for protection, hotspots of each taxon group and irreplaceable sites (squares containing any species recorded in only one or two squares) were firstly selected in 1 km grid squares. Within these selected squares, the boundaries of recommended sites were delineated with the help of expert opinion. The irreplaceable sites were sensitive to data updates, but the hotspots were very robust. Complementarity-based algorithms selected a similar number of squares to those selected as hotspots and irreplaceable sites. The recommendations for an extension of the existing protected areas by 6% (i.e. an additional 2% of Hong Kong's land area) were submitted to the Government in August 2000.To identify biodiversity indicators, the correlation of species richness and variation in species composition among groups of vertebrates (amphibians, reptiles, birds, mammals) and insects (butterflies, moths, dragonflies, Staphylinidae, other Coleoptera, ants, and other Hymenoptera) was investigated. At both the site- ( 1 km2) and plot- ( 1 ha) scales, cross-taxon congruence of species richness and variation in species composition was low, and it was significant only among some insect taxa. Hymenoptera was the best indicator taxon among insects. For Hymenoptera and Coleoptera, the use of presence/absence data showed similar results to those using abundance data in the above analyses, but family assemblages did not retain the pattern seen in the species assemblages. Generalised linear models developed on the basis of environmental variables (topography, habitat, recent disturbance) explained 55% of the variation in species richness of rare plants in 1 km squares, but smaller percentages (