The growing demand for lithium (Li) as a key component in battery production is raising concerns about the possible increase in its level in the environmental matrices. Sustainable processes for the remediation of metal-contaminated sites have been targeted, and plants could be useful for this scope. In this regard, the selection of plant material with an improved ability to tolerate and accumulate Li is required. In this work, a proof-of-concept in microshoots cultivated in vitro condition was performed to evaluate the potential of hemp (Cannabis sativa L.) to grow and accumulate Li when exposed to relevant concentrations of this metal in the medium. The results demonstrated the toxic effect of Li on plant growth even at the lowest Li level tested (50 mg L-1). Increased Li concentrations (150 and 300 mg L-1) caused an impairment of the photosynthetic machinery and an alteration of element uptake, particularly for micronutrients such as Cu, Fe, Zn, Ni, and Co. A remarkable accumulation of Li in the microshoots was detected in relation to the metal concentration in the substrate. The overall data were discussed, providing evidence for the potential of hemp plants to tolerate and accumulate Li. The results of this work could be a reference for further insights into the potential of hemp for Li phytoremediation and phytomining, although the in vitro growth conditions allow them to be highlighted as preliminary indications.

We studied the environmental impact of geothermal activities in the Mt. Amiata area, using on-site spectral analyses of various ecological components. Analytical techniques were based on the study of the "red-edge", which represents the spectral feature of the reflectance spectra defined between red and infrared wavelengths (?) within the range 670-780nm. Since in the study area the geothermal exploitation causes the drifting of contaminants such as Hg, Sb, S, B, As and H2S (hydrogen sulfide) from power plants, the spectral response of vegetation and lichens depends on their distance from the power stations, and also on the exposed surface, material type and other physical parameters. In the present research, the spectral radiance of targets was measured in the field using an Analytical Spectral Device (ASD) Field-Spec(TM)FR portable radiometer. Spectral measurements were made on vegetation and lichen samples located near to and far from geothermal areas and potential pollution sources (e.g., power plants), with the aim of spatially defining their environmental impact. Observations for vegetation and lichens showed correlation with laboratory chemical analyses when these organisms were under stress conditions. The evaluation of relationships was carried out using several statistical approaches, which allowed to identify methods for identifying contamination indicators for plants and lichens in polluted areas. Results show that the adopted spectral indices are sensitive to environmental pollution and their responses spatialstatically correlated to chemical and ecophysiological analyses within a notable distance. © 2013.

Directional reflectance spectra from 400 to 780 nm were acquired at an angle-of-view of 30° for nadir illuminated leaves of four different kinds of plants (Codiaeum variegatum, Eleagnus angustifolia, Pittosporum tobira, Ficus benjamini). We found that, differently from hemispherical reflectance measurements, directional reflectance data do not correlate well with chlorophyll content. This is mainly due to the Fresnel reflections at the air-epidermis and epidermis-inner layer interfaces that gives the main contribute to the reflectance in 400-480 nm band, where chlorophyll absorption is maximum. The inner reflectance (RI), obtained by subtracting the outer reflectance from the measured spectra, was found to correlate to chlorophyll content. A good correlation (r2 = 0.98) of RI(?)/R750 I versus the log(Chl) was obtained for RI(?) in the reflectance maximum in the green band around 550 nm. The error in the determination of Chl content was of about 3.5 ?g/cm2, lower than that obtained by applying previously suggested vegetation indexes to our experimental data.