Aechmea fasciata was evaluated for the first time as a biomonitor of toxic elements, in comparison to the biomonitoring capacity of Tillandsia usneoides, a well-established biomonitor bromeliad species. Plants of both species were exposed to air pollutants from industrial, urban, and agricultural sources, under the tropical seasonal climate, from June/2011 to April/2013, in five sites of São Paulo State, Brazil, for 8 consecutive exposure periods of 12 weeks each. The levels of essential and non-essential elements, including trace metals, were quantified at the end of each exposure. T. usneoides and A. fasciata indicated N, Fe, Zn, Co, Cr, and V as air contaminants in the studied sites, during wet and dry seasons and both species were recommended for qualitative biomonitoring. Concentration levels of N, Ca, S, Fe, Zn, Cu, B, Co, and Ni were significantly higher in T. usneoides than in A. fasciata. However, A. fasciata showed a higher effective retention capacity of Ni, Pb, V, Cu, Fe, Cr, and Co during field exposure, as indicated by the estimate of enrichment factor relative to basal concentrations. This species is more suitable for detecting the atmospheric pollution level of those metals than the T. usneoides. Both species indicated adequately the seasonal differences in the pollution levels of several elements, but T. usneoides presented higher ability for biomonitoring the spatial variations and for indicating more properly the sources of each element in the studied region than the A. fasciata.

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The aim of this study was to evaluate the growth and development of Aechmea blanchetiana Baker L.B. Sm. in vitro on medium with 0.0, 0.145, 1.45 and 14.5 µM Cu and 0.0, 2.75, 27.5 and 275 µM Zn. Significant accumulation of Cu and Zn occurred at 14.5 µM Cu and 27.5 and 275 µM Zn, respectively, and there were no significant changes in contents of the other macro-and micronutrients. Superoxide dismutase (SOD) activity significantly changed in the presence of both metals. Spermine content increased as Zn concentration increased and decreased with increasing concentrations of Cu. There was an accumulation of H 2 O 2 in the leaf tissue of plants grown in 1.45 and 14.5 µM Cu and 27.5 and 275 µM Zn. A. blanchetiana was found tolerant to the Cu and Zn in concentrations used in this study and displays the capacity to accumulate these metals.

The aim of this study was to evaluate the growth and development of Aechmea blanchetiana Baker L.B. Sm. in vitro on medium with 0.0, 0.145, 1.45 and 14.5 µM Cu and 0.0, 2.75, 27.5 and 275 µM Zn. Significant accumulation of Cu and Zn occurred at 14.5 µM Cu and 27.5 and 275 µM Zn, respectively, and there were no significant changes in contents of the other macro-and micronutrients. Superoxide dismutase (SOD) activity significantly changed in the presence of both metals. Spermine content increased as Zn concentration increased and decreased with increasing concentrations of Cu. There was an accumulation of H 2 O 2 in the leaf tissue of plants grown in 1.45 and 14.5 µM Cu and 27.5 and 275 µM Zn.A. blanchetiana was found tolerant to the Cu and Zn in concentrations used in this study and displays the capacity to accumulate these metals.Additional key words: ascorbate peroxidase, ascorbic acid, Bromeliaceae, heavy metals, hydrogen peroxide, polyamines, superoxide dismutase. ⎯⎯⎯⎯

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© iForest -Biogeosciences and Forestry IntroductionThe Brazilian Atlantic biome is recognized as one of the hotspots for the conservation of biodiversity (Forzza et al. 2012), though it is severely affected by diverse human interferences, particularly in the State of São Paulo, southeastern Brazil (Domingos et al. 2003). The semideciduous Atlantic Forest is highly fragmented in central-eastern São Paulo because of the expansion of agriculture and urban and industrial growth (Nalon et al. 2008). Besides the reduction of forest cover, human activities bring about a variety of pollutants from combustion of fuels, waste disposal, long-term sewage sludge and fertilizer application and other sources, which may be toxic to the plant community and modify the chemical status of soil, depending on its original chemical and physical conditions (Nriagu 1990, Sharpley 1995, Schaaf et al. 2004, Pouyat et al. 2008, Lucas et al. 2011. Soil nutrients are among the main factors that regulate plant growth and play an important role in the sustainable use of soils; however, their excess due to pollution from human sources may damage the soils and affect the soil-plant relationships. Air pollution may also disrupt other nutrient cycling processes in natural ecosystems, such as the decomposition of litter (Cotrufo et al. 1995).Most anthropogenic pollutants deposited in forest ecosystems accumulate in the soil surface layers (Ruan et al. 2008), where pollutants are typically immobilized for long periods (Hawkins et al. 1995, Verstraeten et al. 2012. However, these accumulations are considered a "chemical time bomb" (Kabala & Szerszen 2002, Hovmand et al. 2008, because pollutants will eventually be leached into waterways (Miller & Friedland 1994).Increased deposition of sulfur and nitrogen compounds (SO2, NOx and NH3) in natural communities induces soil acidification (Falkengren-Grerup & Tyler 1993, Akselsson et al. 2013, Gao et al. 2013. Soil acidification depletes the basic nutrient cations, causes a decrease of pH, lowers the quality of humus, and accelerates the mobilization of aluminum (Boruvka et al. 2005, Miller & Watmough 2009). The depletion of basic cations from the forest floor alters the mineral nutrition of trees, modifies tree growth patterns (Klumpp et al. 2002, Högberg et al. 2006, Sebesta et al. 2011) and affects the distribution of roots (Joslin & Wolfe 1992). As a consequence, biodiversity, vegetation productivity and dynamics of the soil carbon pool are affected (Binkley et al. 2000).Altogether, such negative effects contribute to the forest decline observed in the Atlantic Rain Forest on the coastal mountain range named Serra do Mar (region of Cubatão, São Paulo State, Brazil). This forest is affected by air pollution from an industrial complex that caused destabilization of the land surface, disturbance of soil processes and landslides (Leitão Filho et al. 1993, Mayer et al. 2000a, 2000b. Furthermore, the large metropolitan regions of the São Paulo State (SE Brazil) are responsible for the intense fragmentation of...

The study exposed in this paper aimed at evaluating the influence of light, temperature and presence or absence of mesocarp in seeds on the germination of Euterpe edulis Mart. (juçara-palm). The germination of seeds with and without mesocarp was assessed in the presence of light (12 h photoperiod) or in the darkness, and at temperatures of 25, 28 or 30C. A complete randomized 2x2x3 (mesocarp presence, light conditions and temperatures) factorial design was used. The seed germinability and the Germination Speed Index (GSI) were evaluated. Seeds of E. edulis were indifferent either to the presence of light or to temperatures of 25, 28 and 30C. The germinability of the seeds with mesocarp was lower (6 to 10%) than those without mesocarp (47 to 75%).

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