부산대학교 도서관

Aims: Vegetation in ironstone outcrops is under potential environmental stressors. The aim of this work was to understand the relationships between the ecological strategies of species from ironstone outcrops in Brazil and their photosynthetic adjustments, and to contribute for the selection of species for the recovery of mined environments. Methods: A total of 22 species belonging to 12 families were selected over canga vegetation. The physiological characteristics, chlorophyll a fluorescence and chlorophyll indices, were evaluated during the rainy and dry seasons. Analysis of competitor, stress-tolerator and ruderal (CSR) ecological strategies was performed during the rainy season for each species using functional leaf characteristics. Results: The species presented the following ecological strategies: tolerance to stress (74.76%), competition (22.31%) and ruderality (2.93%). Despite a weak correlation between the ecological stress-tolerant strategy and photosynthetic variables, the low soil fertility and reduced rainfall during the dry season led to photochemical adjustments. The species were divided into five distinct groups based on the ability to use and dissipate excess light energy. Some species showed maintenance or increments in photochemical efficiency parameters, chlorophyll indices, and the capacity to avoid damage to the photosynthetic complex through a photoprotective process during the dry season. Conclusions: The photochemical responses observed highlighted the diversity of adaptive strategies found in plant species from ironstone outcrops. The different photosynthetic adjustments are related to the competition capacity and stress tolerance mechanisms. Thus, the analyzed physiological parameters can be used for selecting plant species for the recovery of environments impacted by mining companies. [ABSTRACT FROM AUTHOR]