title: Demographic threats to the sustainability of Brazil nut exploitation.
abstract: 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.
authors.affiliation: Centre for Ecology, Evolution and Conservation, School of Environmental Sciences, University of East Anglia, Norwich NR4 7TJ, UK. C.Peres@uea.ac.uk
authors.forename: Carlos A
authors.initials: CA
authors.lastname: Peres
authors.forename: Claudia
authors.initials: C
authors.lastname: Baider
authors.forename: Pieter A
authors.initials: PA
authors.lastname: Zuidema
authors.forename: Lúcia H O
authors.initials: LH
authors.lastname: Wadt
authors.forename: Karen A
authors.initials: KA
authors.lastname: Kainer
authors.forename: Daisy A P
authors.initials: DA
authors.lastname: Gomes-Silva
authors.forename: Rafael P
authors.initials: RP
authors.lastname: Salomão
authors.forename: Luciana L
authors.initials: LL
authors.lastname: Simões
authors.forename: Eduardo R N
authors.initials: ER
authors.lastname: Franciosi
authors.forename: Fernando
authors.initials: F
authors.lastname: Cornejo Valverde
authors.forename: Rogério
authors.initials: R
authors.lastname: Gribel
authors.forename: Glenn H
authors.initials: GH
authors.lastname: Shepard
authors.forename: Milton
authors.initials: M
authors.lastname: Kanashiro
authors.forename: Peter
authors.initials: P
authors.lastname: Coventry
authors.forename: Douglas W
authors.initials: DW
authors.lastname: Yu
authors.forename: Andrew R
authors.initials: AR
authors.lastname: Watkinson
authors.forename: Robert P
authors.initials: RP
authors.lastname: Freckleton
mesh_terms: D031383:Bertholletia / Q000033:anatomy & histology / Q000254:growth & development; D001838:Bolivia; D001938:Brazil; D003198:Computer Simulation; D003247:Conservation of Natural Resources; D018556:Crops, Agricultural; D017753:Ecosystem; D015233:Models, Statistical; D009754:Nuts; D010568:Peru; D011156:Population Density; D025341:Principal Component Analysis; D012044:Regression Analysis; D013997:Time Factors; D014197:Trees