How does Copaifera langsdorffii respond to flooding under different irradiance levels?

Abstract

This study investigated the potential of shading to mitigate the stressful effects of different periods of flooding, favoring the recovery of seedlings in the post-flooding period. Copaifera langsdorffii Desf. seedlings were grown under three different levels of light availability (100%, 70%, and 30%), and two water conditions (control and flooded). During the flooding period, plants were evaluated at 0, 45, and 90 days, and at 45 days after the cessation of each period of flooding to assess post-flooding effects (45 + 45 and 90 + 45 days). There was an increase in internal concentration of CO2, and increased activity of antioxidant enzymes in both the leaves and roots at all levels of light availability, with more pronounced effects under shady conditions (30% brightness). The plants demonstrated the capacity to survive flooding but did not fully recover within 45 days after the suspension of flooding, as evidenced by an evaluation of physiological and biochemical characteristics. We concluded that shading does not mitigate the stressful effects of flooding. Flooding and cultivation under 30% light availability created stressful conditions for the plants, which presented adjustment mechanisms that allowed the resumption of balance up to 45 days after the suspension of flooding, especially when grown under high light conditions.