Logging activity and tree regeneration in an Amazonian forest William E. Magnusson a,* , Odilon P. de Lima a , Francisco Quintiliano Reis b , Niro Higuchi b , Jose  Ferreira Ramos c a Coordenac ,a Äo de Pesquisas em Ecologia, Instituto Nacional de Pesquisas da Amazo Ãnia (INPA), CP 478, 69011-970 Manaus AM, Brazil b Coordenac ,a Äo de Pesquisas em Silvicultura Tropical, INPA, CP 478, 69011-970 Manaus AM, Brazil c Coordenac ,a Äo de Pesquisas em Bota Ãnica, INPA, CP 478, 69011-970 Manaus AM, Brazil Received 21 December 1997; accepted 17 June 1998 Abstract We studied the effect of experimental logging of 4 ha plots on the regeneration of tree species in a forest 90 km north of Manaus, Amazonas, Brazil. Logging resulted in a total reduction in live wood volume of 44±107 m 3 ha 1 , although only 63% of this volume was felled, and only 43% removed from the plots. The density of established regeneration (trees and shrubs with diameter at breast height 10 cm, and height 200 cm) was greater in logged plots than in control plots when measured 3 and 7±8 years after logging. Species richness was also signi®cantly higher in logged plots than in controls. We registered 139 species per 1000 stems, 7±8 years after logging, 143 species per 1000 stems, 3 years after logging, and 136 species per 1000 stems in control plots. Overall species composition was signi®cantly affected by the intensity of logging damage in the plots after 7±8 years, and control plots were signi®cantly different from plots logged 3 years previously. However, changes were not great in relation to natural variation within the forest. Most species increased in density after logging (mean17%), and the number of individuals belonging to species with commercial value on the local market was 15% greater in logged plots than in control plots. The total potential value of the regeneration, based on the value of wood per m 3 (when adult) of the individuals, was 23% higher in logged plots than in control plots, though this difference was not statistically signi®cant. Therefore, enrichment planting is not necessary to maintain either the biodiversity, or potential economic value for wood production, of this forest. Resumen Explotacio Ân experimental de madera en una ¯oresta de la Amazo Ãnia Central aumento  signi®cativamente la densidade de regeneracio  n establecida (a Ârboles y a Ârbustos con dia Âmentro a la altura del pecho 10 cm, y altura 200 cm) en comparacio Âna parcelas control, cuando medido 3 y 7±8 an Äos despue Âs del corte. La riqueza de especies tambien fue  signi®cativamente mayor en parcelas explotadas que en parcelas control. La composicio Ân de espe Âcies total fue  signi®cativamente afectada por la intensidad de dan Äo devido a la extraccio Ân despue Âs de 7±8 an Äos, y parcelas control fuero Ân signi®cativamente diferentes de las parcelas explotadas 3 an Ä os antes. No entanto, los cambios no fueron grandes en relacio  n a la variacio  n natural en la ¯oresta. La mayoria de las espe Âcies aumento  en densidad despue Âs de la explotacio Ân (me Âdia17%), y el numero medio de individuos de espe Âcies comerciales fue  15% mayor en comparacio Ân a parcelas control. El valor total potencial de la regeneracio Ân, baseado Forest Ecology and Management 113 (1999) 67±74 *Corresponding author. Tel.:+55-92-6431834; fax: +55-92-6421838; e-mail: bill@inpa.gov.br 0378-1127/99/$ ± see front matter # 1999 Elsevier Science B.V. All rights reserved. PII: S0378-1127(98)00418-6