关键词: 火, 影响, 草地, 芒萁群落, 香港

Abstract: Fire is an important factor in the natural ecosystem of Hong Kong.Fire and its ecological role in the grassland and fernland are studied.The results show that:(1) Fire is inevitable in the grassland and fernland in Hong Kong.It occurs repeatedly with an interval of 2 or 3 years.Fire is also the most important factor for the stability of grassland and fernland.If the grassland and fernland were protected from hill fire,they would be probably replaced by shrublad followed by forest.(2)Most of the above-ground biomass was contributed by relatively small numhr of species and the species diversity was reduced,bcause fire induces a stronger development of dominated spedes.In addition,many spedes show some form of adaptation and fire resistance in the communities because fire occurs often.(3) Fire increases net primary production in the grassland and improves the quailty of grasses for animals.However,it decreases net primary production in the fernland and also results in an atypical ratio of below-ground/above-ground biomass of woody plants in both communities.

Key words: Fire, Effect, Grassland, Fernland, Hong Kong