Demographic Threats to the Sustainability of Brazil Nut Exploitation
Carlos A. Peres,1*
Claudia Baider,3
Pieter A. Zuidema,4
Lúcia H. O. Wadt,5
Karen A. Kainer,6
Daisy A. P. Gomes-Silva,5
Rafael P. Salomão,7
Luciana L. Simões,8
Eduardo R. N. Franciosi,9
Fernando Cornejo Valverde,10
Rogério Gribel,11
Glenn H. Shepard, Jr.,11
Milton Kanashiro,12
Peter Coventry,12
Douglas W. Yu,2,13
Andrew R. Watkinson,1,2,13
Robert P. Freckleton14
A comparative analysis of 23 populations of the Brazil nut tree (Bertholletia excelsa) across the Brazilian, Peruvian, and Bolivian Amazon shows that the history and intensity of Brazil nut exploitation are major determinants of population size structure. Populations subjected to persistent levels of harvest lack juvenile trees less than 60 centimeters in diameter at breast height; only populations with a history of either light or recent exploitation contain large numbers of juvenile trees. A harvesting model confirms that intensive exploitation levels over the past century are such that juvenile recruitment is insufficient to maintain populations over the long term. Without management, intensively harvested populations will succumb to a process of senescence and demographic collapse, threatening this cornerstone of the Amazonian extractive economy.
1 Centre for Ecology, Evolution and Conservation, School of Environmental Sciences, University of East Anglia, Norwich NR4 7TJ, UK.
2 School of Biological Sciences, University of East Anglia, Norwich NR4 7TJ, UK.
3 Departamento de Ecologia, Universidade de São Paulo, São Paulo–SP, 05508–900, Brazil.
4 PROMAB, Casilla 107, Riberalta, Beni, Bolivia, and Department of Plant Ecology, Utrecht University, Post Office Box 80084, 3508TB Utrecht, Netherlands.
5 Centro de Pesquisa Agroflorestal do Acre, Embrapa, Rio Branco, Acre 69908–970, Brazil.
6 School of Forest Resources and Conservation and Tropical Conservation and Development Program, University of Florida, Gainesville, FL 32611–0410, USA.
7 Departamento de Botânica, Museu Paraense Emílio Goeldi, Belém, Pará 66040–170, Brazil.
8 Rua Aimberé 1485/94, São Paulo, SP 01258–020, Brazil.
9 Rua Dona Balduina 116, São Paulo, SP 01251–020, Brazil.
10 Proyecto Conservando Castañales, Asociación para la Conservación de la Cuenca Amazónica (ACCA), Cusco 499, Puerto Maldonado, Madre de Dios, Perú.
11 Botany Department, Instituto Nacional de Pesquisas da Amazônia (INPA), Manaus, Amazonas 69083–000, Brazil.
12 Embrapa Amazônia Oriental/DFID (Projeto Dendrogene), Belém, Pará 66095–100, Brazil.
13 Tyndall Centre for Climate Change Research, UK.
14 The Mauritius Herbarium, MSIRI, Reduit, Mauritius.
* To whom correspondence should be addressed. E-mail: C.Peres{at}uea.ac.uk
