Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)We assessed the mechanical damage caused by litterfall and vertebrates to seedlings and saplings at the edge and in the interior of three small (14, 20, 29 ha) and one large (9400 ha) fragments of the Atlantic Forest, Sao Paulo, Brazil. We monitored mechanical damage (e.g. litterfall, vertebrate and human damage) of artificial seedlings, and mortality rates for natural seedlings for 1 year at 3 month intervals. Mechanical damage to artificial seedlings was mainly caused by litterfall (68.1%). Damage to artificial seedlings was approximately two times higher in the smaller fragments than in the large fragment, but the mortality of natural seedlings was not related to fragment size. Mechanical damage and mortality did not differ between edge and interior plots. Although it occurred only occasionally (3.78% of total damage) human impact (trampling) seems to be the most important single cause of seedling mortality.502267275Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)FAPESP [99/05123-4, 00/00596-0]CNPq [207132/2004-8]