02926naa a2200709 a 450000100080000000500110000800800410001902200430006002400330010310000170013624500970015326000090025052008670025965000160112665000150114265000230115765000300118065000170121065000180122765000250124565000250127065000220129565000130131765000240133065000270135465000250138165000100140665000260141665300260144265300230146865300230149165300250151465300120153965300260155165300170157765300200159465300220161465300210163665300200165765300240167765300380170165300450173965300270178465300210181170000150183270000190184770000190186670000180188570000260190370000200192970000190194970000240196870000200199270000150201270000260202770000180205370000170207170000140208870000210210270000220212377300710214520576172021-07-02       2003    bl uuuu     u00u1 u    #d  a0036-8075 (print) / 1095-9203 (online)7 a10.1126/science.10916982DOI1 aPERES, C. A.  aDemographic threats to the sustainability of Brazil nut exploitation.h[electronic resource]  c2003  aA 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.  aBrazil nuts  aHarvesting  aIntensive forestry  aNontimber forest products  aPlant growth  aTropical wood  aAnálise comparativa  aBertholletia excelsa  aCastanha do pará  aColheita  aEssência florestal  aExploração florestal  aFator de crescimento  aFlora  aPopulação de planta  aAnálisis comparativo  aCastanha do brasil  aCastanha-do-brasil  aComparative analysis  aCosecha  aCrecimiento de planta  aExtrativismo  aMadera tropical  aManejo de recurso  aManejo florestal  aNuez del Brasil  aPopulação vegetal  aProductos forestales no madereros  aProduto florestal não madeireiro (PFNM)  aSilvicultura intensiva  aSustentabilidade1 aBAIDER, C.1 aZUIDEMA, P. A.1 aWADT, L. H. O.1 aKAINER, K. A.1 aGOMES-SILVA, D. A. P.1 aSALOMÃO, R. P.1 aSIMÕES, L. L.1 aFRANCIOSI, E. R. N.1 aVALVERDE, F. C.1 aGRIBEL, R.1 aSHEPARD JUNIOR, G. H.1 aKANASHIRO, M.1 aCOVENTRY, P.1 aYU, D. W.1 aWATRINSON, A. R.1 aFRECKLETON, R. P.  tScience, Washington, DCgv. 302, n. 5653, p. 2112-2114, Dec. 2003.