Demographic threats to the sustainability of Brazil nut exploitation.
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.
Peres
Carlos A
CA
Centre for Ecology, Evolution and Conservation, School of Environmental Sciences, University of East Anglia, Norwich NR4 7TJ, UK. C.Peres@uea.ac.uk
Baider
Claudia
C
Zuidema
Pieter A
PA
Wadt
Lúcia H O
LH
Kainer
Karen A
KA
Gomes-Silva
Daisy A P
DA
Salomão
Rafael P
RP
Simões
Luciana L
LL
Franciosi
Eduardo R N
ER
Cornejo Valverde
Fernando
F
Gribel
Rogério
R
Shepard
Glenn H
GH
Kanashiro
Milton
M
Coventry
Peter
P
Yu
Douglas W
DW
Watkinson
Andrew R
AR
Freckleton
Robert P
RP
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