01711naa a2200217 a 450000100080000000500110000800800410001902200140006010000320007424500780010626000090018452010910019365000120128470000160129670000230131270000220133570000230135770000200138070000210140077300720142119043832017-07-31       2011    bl uuuu     u00u1 u    #d  a0014-47971 aSOUZA, P. J. de O. PONTE de  aImpacts of soyabean expansion on the Amazon energy balanceba case study.  c2011  aA micrometeorological experiment was carried out in an area of soyabean cultivation located in northeastern Para state, Brazil, in order to evaluate impacts on the local energy balance due to replacement of forests by soyabean. The meteorological data from forest ecosystems were collected in Caxiuanã forests located in central Para. The energy balance components were obtained using the Bowen ratio technique. Differences in energy balance components between ecosystems were significant during the soyabean growing season and more significant between growing seasons. During the soyabean growing season mean impacts of ?15%, ?9% and ?27% on net radiation, latent heat flux (LE) and sensible heat flux (H), respectively, were observed. At specific soyabean stages, LE was higher than in the forest because of the high soyabean surface conductance of water vapour.However, during the production off-season the impacts were more significant (p &lt 0.05), showing a reduction of 78% in LE and a substantial increase in H (84%) because of the absence of vegetation cover over this period.  aEnergia1 aRIBEIRO, A.1 aROCHA, E. J. P. da1 aBOTELHO, M. do N.1 aSOUSA, A. M. L. de1 aSOUZA, E. B. de1 aFARIAS, J. R. B.  tExperimental Agriculture, Cambridgegv. 47, n. 3, p. 553-567, 2011.