Comparative regeneration status in a natural forest and enrichment plantations of Chittagong (south) forest division, Bangladesh

摘要

The natural regeneration of the tree species in pure natural forest stand and enrichment plantations of Baraitali Forest of Chittagong (South) Forest Division, Bangladesh was studied by stratified random quadrat method during April 2002 to November 2002, Totally 100 plots of 3 m X 3 m in size represents a total of 64 regenerating tree species from natural forest with an average seedlings of 24 767/hm~2, while only 40 regenerating tree species were recorded from enrichment plantations with an averageseedlings of 18 633/hm~2. Maximum regeneration in natural forest was found with Castanopsis spp. (2200 seedlings/hm~2) followed by Glochidion lanceoiahum (2183 /hm~2) whereas, in enrichment plantations maximum regeneration was found with Dipterocarpus gracilis (2117/hm~2) followed by Anogeissus acuminata (2000/hm~2). For natural forest, highest relative density was found for Castanopsis spp (8.88%), relative frequency for Glochidion lanceolarium (7.36%), relative abundance for Syzygium spp. (3.79%) andImportance Value Index were recorded with Glochidion lanceolarium (18.24%). The corresponding values for enrichment plantations were highest with Dipterocarpus gracilis (11.36%), Glochidion lanceolarium (9.71%), Dipterocarpus gracilis (5.92%), Glochidionlanceolarium (23 32%) respectively. Stem per hectare of some common trees with their seedlings and saplings in both the natural stands and enrichment plantations showed that only Dipterocarpus gracilis successfully recruited in both sites but recruitment was higher in natural forest. Like many other primary rain forests, the Baraitoli forest typically has both substantial seedlings and soil seed bank from which regeneration may occur. The naturally regenerated seedlings are quite dense but it could notreach the pole stage due to human interference.