Synthesis, Characterization and Ecotoxicity Evaluation of Biochar-Derived Carbon Dots from Spruce Tree, Purple Moor-Grass and African Oil Palm

Biochar-derived C-Dots from Picea, Molinia caerulea and Elaeis guineensis were synthesized through a hydrothermal process, and their physicochemical and optical characteristics and environmental effects were compared. These C-Dots were characterized by techniques such as Attenuated Total Reflection–Fourier Transform Infrared (ATR-FTIR), UV-Vis spectrophotometry, fluorescence spectroscopy, dynamic light scattering (DLS), Z potential, and High-Resolution Transmission Electronical Microscopy (HR-TEM). The ecotoxicity tests were performed using the Microtox™ test, making this study one of the few that use this method. The C-Dots from Molinia caerulea showed the best quantum yield (QY) of 8.39% and moderate ecotoxicity, while Elaeis guineensis has the lowest QY (2.31%) but with zero toxicity. Furthermore, the C-Dots from Picea presents good optical properties but showed high toxicity and limits its use. Finally, all C-Dots showed functional groups that could be biofunctionalized with biomolecules, especially C-Dots from Molinia caerulea and Elaeis guineensis show potential for use in the development of optical biosensors.

Using Dartmoor ponies in conservation grazing to reduce Molinia caerulea dominance and encourage germination of Calluna vulgaris in heathland vegetation on Dartmoor, UK

The increasing dominance of purple moor-grass Molinia caerulea in heathland ecosystems in the UK is of growing concern due to its detrimental impact on plant and animal diversity on sites of nature conservation interest. The use of free-ranging ponies to reduce Molinia dominance was investigated from 2017 to 2019 within a 425 ha site on Dartmoor, UK. Salt blocks were used to attract the ponies to a Molinia-dominated area of heath within the site, away from their previously-preferred grazing areas. The impact of pony grazing was assessed by measurements of vegetation structure and plant species composition. The increased presence of ponies in the vicinity of the salt blocks increased the percentage occurrence of bare ground, reduced sward surface height, reduced percentage occurrence of Molina and increased the germination of heather Calluna vulgaris seedlings. The conclusions of this research are that salt blocks can be used to attract ponies to graze targeted areas of Molinia-dominated heathland. Through their grazing and trampling, ponies can reduce the dominance of Molinia, leading to an increase in the germination and establishment of heather seedlings.

Clonal micropropagation of decorative cereal Molinia caerulea (L.) Moench

The research is devoted to the development of clonal micro-propagation technology of the decorative cereal Molinia caerulea (L.) Moench. The concentration of 2.0 mg /l of cytokinin 6-benzylaminopurine (6-BAP) contributed to obtaining the maximum number of microshoots: 6.3 and 7.9 pcs. on Anderson's and Murashige-Skoog's (MS) media, respectively, which exceeded the control (by 4.7 and 6.3, respectively, with LSD05 = 2.3). The length shoots were observed on hormone-free media, this indicator significantly decreased with an increase in 6-BAP content. On Anderson and MS media with 1.0 mg/l 6-BAP, the shoot length averaged 21.5 and 26.4 mm, respectively, which made it possible to transplant them for rooting, bypassing planting on a medium for elongation. The inclusion of the Siliplant micro-fertilizer in the MS medium at doses of 1.0 and 2.0 ml/l contributed to a significant increase in shoot size, by 16.7 and 10.7 mm (LSD05 = 8.9), respectively, in comparison with the control (MS). It is recommended to use Anderson's medium and 0.5 mg/l of indole-3-acetic acid as a medium for rhizogenesis: after two weeks of cultivation, the regenerants had a standard appearance with developed roots suitable for planting for adaptation. At the adaptation stage, watering the substrate with the biofungicide «Trichoderma veride» according to the instructions and a cereals single spraying with the micro-fertilizer «Siliplant» at a dose of 1.5 ml/l contributed to their 100 % survival rate.

CO₂ and CH₄ budgets and global warming potential modifications in <i>Sphagnum</i>-dominated peat mesocosms invaded by <i>Molinia caerulea</i>

Plant communities play a key role in regulating greenhouse gas (GHG) emissions in peatland ecosystems and therefore in their ability to act as carbon (C) sinks. However, in response to global change, a shift from Sphagnum-dominated to vascular-plant-dominated peatlands may occur, with a potential alteration in their C-sink function. To investigate how the main GHG fluxes (CO2 and CH4) are affected by a plant community change (shift from dominance of Sphagnum mosses to vascular plants, i.e., Molinia caerulea), a mesocosm experiment was set up. Gross primary production (GPP), ecosystem respiration (ER) and CH4 emission models were used to estimate the annual C balance and global warming potential under both vegetation covers. While the ER and CH4 emission models estimated an output of, respectively, 376±108 and 7±4 g C m−2 yr−1 in Sphagnum mesocosms, this reached 1018±362 and 33±8 g C m−2 yr−1 in mesocosms with Sphagnum rubellum and Molinia caerulea. Annual modeled GPP was estimated at -414±122 and -1273±482 g C m−2 yr−1 in Sphagnum and Sphagnum + Molinia plots, respectively, leading to an annual CO2 and CH4 budget of −30 g C m−2 yr−1 in Sphagnum plots and of −223 g C m−2 yr−1 in Sphagnum + Molinia ones (i.e., a C sink). Even if CH4 emissions accounted for a small part of the gaseous C efflux (ca. 3 %), their global warming potential value makes both plant communities have a climate warming effect. The shift of vegetation from Sphagnum mosses to Molinia caerulea seems beneficial for C sequestration at a gaseous level. However, roots and litter of Molinia caerulea could provide substrates for C emissions that were not taken into account in the short measurement period studied here.

CO₂ and CH₄ budgets and global warming potential modifications in <i>Sphagnum</i>-dominated peat mesocosms invaded by <i>Molinia caerulea</i>

Plant communities play a key role in regulating greenhouse gas (GHG) emissions in peatland ecosystems and therefore in their ability to act as carbon (C) sinks. However, in response to global change, a shift from Sphagnum to vascular plant-dominated peatlands may occur, with a potential alteration in their C-sink function. To investigate how the main GHG fluxes (CO2 and CH4) are affected by a plant community change (shift from dominance of Sphagnum mosses to vascular plants, i.e. Molinia caerulea), a mesocosm experiment was set up. Gross primary production (GPP), ecosystem respiration (ER) and CH4 emission models were used to estimate the annual C balance and global warming potential under both vegetation covers. While the ER and CH4 emission models estimated an output of, respectively, 376 ± 108 and 7 ± 4 gC m−2 y−1 in Sphagnum mesocosms, this reached 1018 ± 362 and 33 ± 8 gC m−2 y−1 in mesocosms with Sphagnum rubellum and Molinia caerulea. Annual modelled GPP was estimated at −414 ± 122 and −1273 ± 482 gC m−2 y−1 in Sphagnum and Sphagnum + Molinia plots, respectively, leading to an annual CO2 and CH4 budget of −30 gC m−2 y−1 in Sphagnum plots and of −223 gC m−2 y−1 in Sphagnum + Molinia ones (i.e., a C-sink). Even if, CH4 emissions accounted for a small part of the gaseous C efflux (ca. 3 %), their global warming potential value makes both plant communities have a climate warming effect. The shift of vegetation from Sphagnum mosses to Molinia caerulea seems beneficial for C sequestration at a gaseous level. However, roots and litters of Molinia caerulea could provide substrates for C emissions that were not taken into account in the short measurement period studied here.

Content of Zn, Cd and Pb in purple moor-grass in soils heavily contaminated with heavy metals around a zinc and lead ore tailing landfill

The paper presents concentrations and correlations between Zn, Cd and Pb in the aboveground parts of purple moor-grass (Molinia caerulea L.) in forest soils heavily contaminated with heavy metals around a zinc and lead ore tailing landfill at Mining & Metallurgy Enterprise “Bolesław” SA in Bukowno. Field observations have indicated that purple moor-grass, which occurs as one of the few vascular plants in locations with tailing mud, is probably a species with high adaptability to conditions in contaminated environments. The research was carried out in a network of 20 regular monitoring sites. At these sites, a detailed inventory of purple moor-grass was carried out and samples of the aboveground parts of the plants were collected from the leaves and ears and from the soil at a depth of 0-20 cm. It was found that there was no significant correlation between the concentration of heavy metals in the soils and aboveground parts of the plants in the most heavily contaminated zones. This may indicate the existence of mechanisms limiting uptake of heavy metals by this species, and therefore the need for further research in the context of its suitability for biological regeneration of tailing landfills and phytosanitary protection of adjoining areas.