New Forests (2011) 41:247–262 DOI 10.1007/s11056-010-9225-9 Population changes of early successional forest species after shifting cultivation in Northwestern Vietnam Tran Van Do · Akira Osawa · Nguyen Toan Thang · Nguyen Ba Van · Bui Thanh Hang · Cam Quoc Khanh · Le Thi Thao · Diep Xuan Tuan Received: July 2010 / Accepted: 30 September 2010/ / Published online: 15 October 2010 © Springer Science+Business Media B.V 2010 Abstract The population changes of early successional forest species, Wendlandia paniculata, Schima wallichii, Camellia tsaii, and Lithocarpus ducampii, were described and analyzed in a chronosequence of 1–30 year-old secondary forests representing regrowth after shifting cultivation in northwestern Vietnam, utilizing 51 temporary plots for stem census Another five temporary plots were used for stem census in surrounding old-growth forest for comparison In the first year after land abandonment, seedling stem density (H \ m) was 65,800/ha, increasing to 161,200/ha by third year, then sharply decreasing to 2,500/ha in 21–30 year-old forests The sapling stratum (H ≥ m and DBH \ cm) started to be recruited in the fifth year, increasing to reach a peak density of 4,530 stems/ha at year ten, then decreased to 580 stems/ha at year 21–30 The tree stratum (DBH ≥ cm) achieved the maximum density of 600 stems/ha at year ten Meanwhile, the density of all strata in the old-growth forest was 2,980 stems/ha Sprouts played an important role, accounting for 34% at the first year then increased gradually to 73% at year 21–30 Total basal area attained a peak at 5.43 m2/ha at year ten; it was 4.9 m2/ha in the old-growth forest These four species played an important role in providing ecological services for recruitment of other species during the first 10 years of fallow stand development, which increased to 35 species in 21–30 year-old secondary forest Keywords Basal area · Crown area · Fallow age · Old-growth forest · Secondary forest regrowth T Van Do · A Osawa Laboratory of Forest Utilization, Graduate School of Agriculture, Kyoto University, Kyoto 606-8502, Japan T Van Do · N Toan Thang · N Ba Van · B Thanh Hang Silviculture Research Division, Forest Science Institute of Vietnam, Tu Liem, Ha Noi, Vietnam C Quoc Khanh · L Thi Thao · D Xuan Tuan Northwestern Forest Research Center, Forest Science Institute of Vietnam, Son La Town, Vietnam T Van Do (&) Kitashirakawa Oiwake-cho, Sakyo-ku, Kyoto 606 -8502, Japan e-mail: doanh@kais.kyoto-u.ac.jp; dotranvan@hotmail.com 123