REHABILITATION AND DEVELOPMENT OF FOREST ON DEGRADED HILLS OF HONG-KONG

Hong Kong's potential climax vegetation is subtropical evergreen monso on forest but all of the original forest has been cleared by centuries of human activities. Rehabilitation of forest in Hong Kong was starte d as early as 1880, but all the early plantations were destroyed durin g the Japanese Occupation between 1942 and 1945. Most of the existing forest has developed since 1945, through either natural succession or afforestation on degraded areas protected from fire and other disturba nce. Currently 14% of the land area is covered in forest comprising tw o-thirds of this natural secondary forest and one-third plantations. T hese forests play an important role in conservation and environmental maintenance. Surveys of Hong Kong's forests were carried out between 1 989 and 1996 to investigate their successional status and floristic di versity. The study indicated that natural succession was the major pro cess for forest restoration on degraded lands in Hong Kong. In the abs ence of fire and other disturbances, all the degraded lands could pote ntially be restored to closed secondary forest in 30-40 years. Affores tation can facilitate forest formation, but the ecological function of most plantations was generally weak because most planted species were fast-growing exotics. However, floristic diversity of plantations inc reased with age by the invasion and establishment of native species. F ire was the major limiting factor for the development of secondary for est and plantations. Forest rehabilitation on degraded areas can be gr eatly accelerated if fires are efficiently controlled. (C) 1997 Elsevi er Science B.V.