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We examine the hypothesis that the chlorophyll a fluorescence technique can be an efficient tool to support the selection of species adapted to high irradiance and therefore, suitable for use in initial rehabilitation projects of degraded areas. The experiment was conducted at the Pedro de Moura Operational Base, Amazonas, Brazil. The fluorescence transients were obtained using a portable fluorometer for leaves of Bombacopsis macrocalyx (Bm), Eugenia cumini (Ec), Iryanthera macrophyla (Im) and Senna reticulata (Sr), which were subjected to high irradiance between 12:00 am and 1:00 p.m. Using the OJIP test, the following were calculated: performance index (PI ABS), density of reaction centres per cross section (RC/CS), maximum efficiency of photosystem II (phiPo), and probability of energy excitation (psio) or that an absorbed photon (phiEo) moves an electron beyond quinone A. The highest value of PI ABS was found in Ec (0.40) while the lowest values were found in Bm (0.08) and Im (0.06). These low values of PI ABS in Bm and Im were a result of the low values for RC/CS (121 for Bm; 142 for Im) and phiPo (0.50 for Bm; 0.48 for Im) when compared to the values in Ec (RC/CS=303; phiPo=0.72) and Sr (RC/CS=326; phiPo=0.73). It was also observed that in Sr the decrease in PI ABS when compared with Ec resulted from a low value of psio, which was 32 % lower than the value found in Ec. Regarding the PI ABS per plant, Ec had the largest number of individuals with high performance while Im and Bm had the largest numbers of individuals with low performance. In conclusion, the chlorophyll a fluorescence technique enabled the evaluation of the photochemical performance of plants in the field, in turn permitting the selection of species most suitable for rehabilitation of degraded areas. Neste trabalho, examinamos a hipótese de que a técnica de fluorescência da clorofila a possa ser uma ferramenta eficiente para dar suporte à seleção de espécies adaptadas à alta irradiância e, entretanto, aptas a serem utilizadas em plantios de recuperação de áreas degradadas. Realiizou-se o experimento na Base de Operações Geólogo Pedro de Moura, Amazonas, Brasil. Os transientes de fluorescência foram obtidos utilizando-se um fluorômetro portátil, em folhas de Bombacopsis macrocalyx (Bm), Eugenia cumini (Ec), Iryanthera macrophyla (Im) e Senna reticulata (Sr) submetidas a alta irradiância, no período entre 12 e 13h. A partir do teste OJIP, calcularam-se: o índice de desempenho (PI ABS), a densidade de centros de reação por seção transversal (RC/CS), a eficiência máxima do fotossistema II (fiPo) e a probabilidade da energia de excitação (psio) ou de um fóton absorvido (fiEo) mover um elétron após a quinona A. Observou-se maior valor de PI ABS em Ec (0,40), e, os menores, em Bm (0,08) e Im (0,06). Esses baixos valores resultaram dos baixos valores de RC/CS (121 para Bm; 142 para Im) e fiPo (0,50 para Bm; 0,48 para Im) quando comparados com os exibidos por Ec (RC/CS = 303; fiPo = 0,72) e Sr (RC/CS = 326; fiPo = 0,73). Observou-se, ainda, que em Sr, a diminuição de seu PI ABS quando comparada com Ec, resultou do baixo valor de psio, no qual Sr apresentou 32 % menor que Ec. Quanto ao PI ABS por planta, Ec revelou o maior número de indivíduos com alto desempenho, e Im e Bm, o maior número de indivíduos com baixo desempenho. Conclui-se, portanto, que, por meio da técnica da fluorescência da clorofila a, foi possível diagnosticar o desempenho fotoquímico das plantas no campo, selecionando as espécies mais aptas à recuperação de áreas degradadas

Utilization of the chlorophyll a fluorescence technique as a tool for selecting tolerant species to environments of high irradiance