Structural Characteristics of Natural Limestone Forests in Cat Ba Biosphere Reserves, Vietnam
Tran Hai Long *
Silviculture Research Institute, Vietnamese Academy of Forest Sciences, 46 Duc Thang, Bac Tu Liem, Hanoi, Vietnam. and Department of Agriculture, Forestry, and Bioresources, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 08826, Republic of Korea.
I. M. Sangjun
Department of Agriculture, Forestry, and Bioresources, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 08826, Republic of Korea.
Trieu Thai Hung
Silviculture Research Institute, Vietnamese Academy of Forest Sciences, 46 Duc Thang, Bac Tu Liem, Hanoi, Vietnam.
Qiwen Li
Department of Agriculture, Forestry, and Bioresources, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 08826, Republic of Korea.
Ninh Viet Khuong
Silviculture Research Institute, Vietnamese Academy of Forest Sciences, 46 Duc Thang, Bac Tu Liem, Hanoi, Vietnam.
Nguyen Van Tuan
Silviculture Research Institute, Vietnamese Academy of Forest Sciences, 46 Duc Thang, Bac Tu Liem, Hanoi, Vietnam.
Tran Hoang Quy
Silviculture Research Institute, Vietnamese Academy of Forest Sciences, 46 Duc Thang, Bac Tu Liem, Hanoi, Vietnam.
Trinh Ngoc Bon
Silviculture Research Institute, Vietnamese Academy of Forest Sciences, 46 Duc Thang, Bac Tu Liem, Hanoi, Vietnam.
Tran Cao Nguyen
Silviculture Research Institute, Vietnamese Academy of Forest Sciences, 46 Duc Thang, Bac Tu Liem, Hanoi, Vietnam.
Le Thi Thu Hang
Research Institute for Forest Ecology and Environment, Vietnamese Academy of Forest Sciences, 46 Duc Thang, Bac Tu Liem, Hanoi, Vietnam.
Tran Van Do
Silviculture Research Institute, Vietnamese Academy of Forest Sciences, 46 Duc Thang, Bac Tu Liem, Hanoi, Vietnam.
*Author to whom correspondence should be addressed.
Abstract
An ecological understanding of natural forests after anthropogenic intervention is important for sustainable forest management. This study analyzed the overstory characteristics (species composition, growth, and diameter distribution) and regeneration (species richness, density, and height distribution) in natural limestone forests in Cat Ba Biosphere Reserve, Vietnam. Data were collected in nine study plots established in selective-logged (SLF), clear-cut (CCF), and unlogged (UF) forests. Results indicated that the overstory characteristics of SLF and CCF were lower than that of UF (species richness was 33 in UF, 20 in SLF, and 16 in CCF; DBH was 20.6 ±13.7 cm in UF, 16.9 ±9.7 cm in SLF, and 10.5 ±3.8 cm in CCF; Basal area was 38.2 m2 ha-1 in UF, 24.0 m2 ha-1 in SLF, and 11.4 m2 ha-1 in CCF). For regeneration, species richness also varied from UF (25) to SLF (13) and CCF (5), while seedling density reversely increased. We concluded that a 20-year restoration was insufficient for artificially disturbed forests to recover their ecological functions, regardless of logging intensities and techniques applied.
Keywords: Natural limestone forest, forest harvesting, overstory, regeneration, forest restoration.