关键词: 香港, 外来种, 入侵种

AbstractLandscape has been defined as a land area with groups of plant communities or ecosystems forming an ecological unit with distinguishable structure, function, geomorphology, and disturbance regimes. Landscape diversity is the number of ecosystems, or combinations of ecosystems, and types of interactions and disturbances present within a given landscape. We explored dynamics of forest landscape diversity in Heilongjiang Province during 1949-1981. According to the map of forest resource distribution in 1949 and 1981, some representative quantitative indices of landscape diversity, including patch density, perimeter-area fractal dimension, aggregation, interspersion and juxtaposition index, Shannon′s diversity index, and dominance, were selected to describe the changes in the spatial pattern of landscape elements with the support of ESRI′S ARCGIS 8 and FRAGSTATS 3.3 software. The results showed that forest landscape spatial pattern in the region has tended to become fragmented, with Korean pine forest the most severely affected. Based on comparison of patch diversity, pattern diversity and type diversity, patches of primitive forest landscape decreased in abundance or were replaced by other landscape types, indicating that spatial variation of landscape pattern, as well as the diversity and evenness of the whole forest landscape declined over the 32 years, while dominance increased. Human irrational activities, such as unplanned logging and farming, changed landscape heterogeneity and resulted in changes in landscape diversity. Protecting natural forest resources, combining logging with afforestation, and sustainable use of forests is the only way to solve all of the problems.

Key words: Hong Kong, exotic species, invasive species