Pollutants in soils are detrimental to ecosystems and agricultural production and may also be a pressing threat to human health. In this context, biochar could be used as part of nature-based solutions to remediate polluted areas. In this work, a series of innovative biochar-based strategies were tested in a soil contaminated by hydrocarbons C > 12 and copper (Cu) to investigate their effectiveness in soil decontamination and revegetation potential. Specifically, biochar was applied to soil alone (SB) or combined with bioaugmentation (SBB) and/or phytoremediation (SBP and SBBP) techniques. Overall results showed that after nine months (T9) biochar added to soil increased hydrocarbon degradation to 66.7% with respect to control soil (46%, natural attenuation). Moreover, the biochar in combination with a microbial consortium and/or plants significantly increased hydrocarbon removal by up to 90%. Concurrently, the fraction of Cu associated with organic matter, characterized by low bioavailability, increased significantly (1.4–2-fold) when biochar was applied. Soil microbial abundance increased over time in all conditions, reaching highest values in SBB and SBBP. This was associated with the higher levels of available phosphorus in the soil. The consortium’s presence enhanced plant growth compared to SB. On the contrary, plants grown on contaminated soil alone were not able to survive until the end of the experiment. Overall, the results of this work make a significant contribution to the understanding of the interaction of biochar with contaminants, plants and microorganisms, providing a useful tool for future brownfield revegetation/remediation programs.
The widespread occurrence of microplastics (MPs) has resulted in their interaction with biological processes. Thus, there is a great concern about the potential toxicity of MPs on animal and plant cells and on the possibility that MPs reach humans through the food web. In order to shed light on both issues, laboratory assays were performed for evaluating the effects of polyethylene (PE) microparticles on the aquatic plant Spirodela polyrhiza (L.) Schleid. and the gammarid Echinogammarus veneris (Heller, 1865). Moreover, a stock of MP-treated Spirodela plants was used to feed gammarid individuals, and the presence of MP particles in their digestive tracts was analyzed. Results evidenced the lack of toxic effects of MPs on plants, evaluated at growth and physiological level by biometric parameters, pigment content, and photosynthetic performance estimated by chlorophyll fluorescence imaging through the ETPT (EcoTox Photosystem Tool). Only a slight reduction in pigment-related indices in MP-treated plants was observed. A remarkable genotoxic effect was instead highlighted by Comet assay in the hemocytes of gammarid individuals exposed to MPs, with three times more DNA damage (expressed as Tail Moment) in MP-treated individuals compared to control ones. Finally, the gut content of the gammarids fed with MP-treated plants revealed the presence of 7.6 MP particles/individual, highlighting the occurrence of trophic transfer of MPs among freshwater ecosystem organisms. Novel indications about the potential impact of the PE microparticles in the aquatic compartment are provided. Notably, the transfer of MP particles between primary producer and primary consumer organisms of the freshwater trophic chain and the genotoxic effects associated with the ingestion of such particles by gammarids are issues of concern for the aquatic ecosystem and the food web leading to the human diet.
The predicted increase in demand for minor metals for modern technologies raises major concerns regarding potential environmental concentration increases. Among the minor metals, lithium (Li) is particularly noteworthy due to growing demand for battery production. Concerns have been raised about the impact on biota of increasing Li concentrations in the environment. To expand the knowledge of the effects of Li on plants, garden cress (Lepidium sativum L.), a model plant for ecotoxicity assay, was tested in a 72 h test in Petri plates. The results showed a stimulation effect of Li at the lowest concentration (Li chloride 10 mg L−1) on seed germination and primary root elongation. Conversely, higher Li concentrations (50 and 150 mg L−1) caused a progressive impairment in both parameters. A genotoxic effect of Li on root cells, evaluated through the alkaline comet assay, was observed at each concentration tested, particularly at 150 mg L−1 Li chloride. Elemental analysis showed that Li accumulated in the seedlings in a dose–concentration relationship, confirming its ability to be readily absorbed and accumulated in plants. Given the likely increase in Li levels in the environment, further research is required to clarify the toxicity mechanisms induced by Li on growth and nucleic acids.
Nature-based solutions inherently require a multifaceted perspective that encompasses diverse fields. The aim of this project is to develop more effective nature-based solutions, climate action and environmental awareness by breaking down boundaries between disciplines and fostering a co-creative process. Concepts of ecology and urban forestry were combined with the research on political ecology, environmental humanities, land art, regenerative art, performing art, participatory art, and more-than-human art. This process resulted in the creation of Aula Verde Aniene. It is located in an urban park in Rome and consists of a stand of trees arranged in circles with a specific design to give the perception of being in an outdoor vegetated room. The project activities involved community participation through art performances and citizen science initiatives. Regulating and cultural ecosystem services of Aula Verde were assessed using i-Tree Eco software and citizens’ surveys. Beyond numerical descriptions of ecosystem services, the manuscript introduces shinrin-yoku as a practice to raise awareness of nature. The distinctive approach here described contributed to convey a sense of belonging to the ecosystem to citizens. The project framework and study findings have been developed to formulate policy recommendations and disseminate a format that can be adapted to diverse locations.
10 November 2020 in Journal of Environmental Planning and Management
An attempt to link phytomanagement, art and social involvement is presented. The “Remediation” Project started up from the search of sustainable solutions for the management of a riparian area in the city of Rome. With the participation of citizens, researchers carried out a preliminary survey on the presence of metals within the target ecosystem and a demonstrative experiment on phytoremediation. Several social and cultural events have been organized in connection with the scientific part of the project: a public debate, an art exposition, a performance and two workshops at the experimental field. The Project demonstrated that through art it is possible to raise curiosity on scientific issues; the participated survey on metal pollution highlighted the strict interconnection among environmental matrices (soil/water/bioma) and thus the risk of contamination transfer; the demonstrative experiment, even if very basic in order to be easily approached by citizens, showed the great potential of Nature Based Solutions.
In the face of mounting challenges related to limited availability of urban land and ecological degradation, emerging novel ecosystems offer unique opportunities for ecological regeneration, social redefinition of space, and alternative urban visions. This study presents the multi-layer analysis of the Goccia Forest in Milan (Italy), a wild urban woodland that has developed over sealed and polluted post-industrial land, aiming to investigate the potential of this novel ecosystem to sustain Nature-based Solutions (NbSs). Using an integrated approach (surveys on fauna, vascular flora, lichens, analysis of forest evolution, mapping of sealed surfaces, and soil characterization) the research looks at the novel ecosystem as a whole, highlighting its ecological dynamics and Ecosystem Services (ES). La Goccia Forest serves as a prime example of how the implementation of NbSs is intricately intertwined with the spontaneous regeneration of urban brownfields. The present study offers the opportunity to rethink urban policies, ensuring their alignment with the demands of the population and the latest scientific knowledge.