02334naa a2200301 a 450000100080000000500110000800800410001902400330006010000210009324501450011426000090025930000080026852014100027665000110168665000220169765000260171965000250174565000200177065000240179065000330181465000290184765000110187665000210188770000230190870000210193170000230195277300570197514004852022-12-06       1999    bl uuuu     u00u1 u    #d7 a10.1023/A:10062401022072DOI1 aSÁ, T. D. de A.  aSpectral irradiance and stomatal conductance of enriched fallows with fast-growing trees in eastern Amazonia, Brazil.h[electronic resource]  c1999  cil.  aThe biomass production of both indigenous and introduced plant species in tropical fallow systems depends on the degree to which these species can acclimate to the light and water environments. Results for light spectral composition monitoring within the canopy of enriched fallows and for the leaf stomatal conductance of fast-growing leguminous trees and indigenous fallow species are presented. All measurements were made in a smallholder farm in Igarapé-Açu, northeastern Pará State, Brazil. Light spectral composition (330 to 1100 nm) was monitored at two heights (ground level and 1 m) in a six-year-old natural fallow, 1.5-year-old natural fallow, and 1.5-year-old fallows enriched with Acacia angustissima, Acacia mangium, Clitoria racemosa, Inga edulis, Sclerolobium paniculatum, and a mixture of these trees. Light-quality parameters including photosynthetically active radiation, phytochrome active radiation, and blue active radiation changed most drastically in the stands enriched with A. mangium. Stomatal conductance was higher for A. mangium than the other trees and four common indigenous fallow vegetation species (Phenakospermum guyannense, Davilla rugosa, Lacistema pubescens, and Myrcia bracteata). Results suggest that the enrichment of fallows with A. mangium may promote changes in light and water vapor exchange regimes, with potential effects on species diversity in fallows.  afallow  anitrogen fixation  anutrient availability  ashifting cultivation  asolar radiation  aCultivo Migratório  aDisponibilidade de Nutriente  aFixação de Nitrogênio  aPousio  aRadiação Solar1 aOLIVEIRA, V. C. de1 aARAUJO, A. C. de1 aBRIENZA JUNIOR, S.  tAgroforestry Systemsgv. 47, n. 1, p. 289-303, 1999.