Qualitative distribution of chemical elements in leaves of <i>Tillandsia</i> grown in urban and natural environments

Epiphytic plants, such as those of the genus Tillandsia, accumulate elements from the air, reflecting the atmospheric composition. This study analyzed the species Tillandsia pohliana Mez, Tillandsia recurvata (L.) L., and Tillandsia loliacea Mart. ex Schult. &amp; Schult.f. in urban environments and in surrounding preserved areas (natural environment), identifying, quantifying, and localizing the chemical elements in tissues via methods such as spectrometry (inductively coupled plasma mass spectrometry (ICP-MS)), electron microscopy (scanning electron microscopy (SEM)-energy dispersive spectrometer (EDS)), and light microscopy. The impact of the urban environment on plant metabolism was assessed using chlorophyll fluorescence analysis. The results revealed differences in the composition and location of the chemical elements in the leaves of the three species in the two environments. Plants grown in urban areas had relatively high concentrations of macronutrients, especially in peltate scales, but did not reach toxic levels. These concentrations of macronutrients did not appear to have any deleterious effects on photochemical rates and may even increase their photochemical efficiency, as observed for T. recurvata and T. pohliana. No higher concentrations of heavy or nonessential metals were observed, suggesting that the peltate scales function as efficient physical barriers to these elements. These results emphasize the complexity of plant responses to environmental conditions and the importance of continuous research to understand the impacts of urbanization and atmospheric pollution.