THE GAP PHASE REGENERATION IN A TROPICAL MON TANE RAIN FOREST IN BAWANGLING, HAINAN ISLAND STUDY ON THE STRUCTURE CHARACTERIS TICS AND REGENERATION DYNAMICS OF CHINESE SPRUCE FORESTS IN QINLING MOUNTAINS Regeneration Dynamics of Young Pinus thunbergii and Its Influencing Factors in the Coastal Protection Forests in Northern Shandong Peninsula Study on the Regeneration Niche of Major Tree Species in Gaps in a Tropical Montane Rain Forest in Bawangling, Hainan Island Study on the populations regeneration dynamics of Pinus armandii in Xiaolongshan Nature Reserve