Phyto-dehydration of confined sludge: a sustainable approach for the management of polluted ponds

Purpose

Leaf transpiration drives many of the processes involved in phyto-technologies, and it can represent a useful mechanism to remove water from different kind of storage basins presenting inorganic, organic or microbiological contamination (phyto-dehydration), with the aim to reduce the risk of environmental contamination. In this framework, a mesocosm-scale trial was carried out to test the capacity of different helophyte species to reduce the excess of water in an artificial pond filled with oversaturated sludge.

Materials and methods

The sludge derives from the digestion of pig slurries, presents high levels of zinc and copper and for most of the year is covered by a water layer of about 20 cm due to rainfalls. This layout (water layer over the sludge) was reproduced inside the mesocosms, where four helophyte species (Phragmites australis and a mix of Carex acutiformis, Iris pseudacorus and Juncus effusus) were planted on floating frames. Plant growth and functionality were monitored for one year, along with their water consumption capacity; the vegetation impact on sludge chemistry, sludge microbial community and sludge greenhouse gases emission/uptake were also evaluated. The sensitivity of the phyto-dehydration system to the reduction of water level occurring during summer in the pond was investigated reducing the water input to the mesocosms.

Results and discussion

P. australis and C. acutiformis successfully established in the mesocosms, while a significant mortality was recorded for I. psudacorus and J. effusus. Once established, plants were able to grow in the mesocosms, and no metal toxicity effect was observed on photosynthesis rates that were comparable with values reported for natural stands of the species. Plants significantly increased (from 24 to 63%, depending on the species) the amount of water lost by the mesocosms and counteracted the reduction of sludge organic carbon that could lead to a mobilization of the heavy metals bound to organic matter: furthermore, plants decreased the rates of mesocosm greenhouse gas emission and reduced the sludge pathogen (Enterobacteriaceae) occurrence. Water limitations reversibly reduced the water consumption and CO₂ uptake capacity of the mesocosms.

Conclusions

The results of this study demonstrated that the water balance of a sludge/water system can be effectively modified through the phyto-dehydration approach, increasing significantly the amount of water lost. Although the low tolerance of two species to the sludge/water environment after plantation needs to be further investigated, this phyto-technology can represent a promising approach to manage the excess of water in polluted ponds.

     

A spatial dataset of forest mensuration collected in black pine plantations in central Italy

Key message

The dataset provides an exhaustive tree inventory with forest mensuration and spatial location carried out in 54 plots sampled in 45- to 55-year-old black pine plantations, located in two areas of Tuscany (central Italy). Forest mensuration includes horizontal and vertical structure measurements and a total of 4171 trees were geo-referenced. The most abundant species was the black pine, Pinus nigra spp. laricio , for which a total of 3631 trees were observed. The dataset was collected as part of the SelPiBio LIFE project (LIFE13 BIO/IT/000282). Dataset access at   http://doi.org/10.5281/zenodo.438681 . Associated metadata available at https://metadata-afs.nancy.inra.fr/geonetwork/apps/georchestra/?uuid=73591027-0f1e-40a3-95d0-b614517c1290&hl=eng .

Context

The main aim of the SelPiBio LIFE project (www.selpibio.eu) is to demonstrate the effects of two thinning regimes, selective and from below, on soil biodiversity in young black pine stands. The spatial structure of forests and the relationships between trees are a good proxy of overall biodiversity level. Spatial datasets with geo referenced trees and related mensurational data represent the highest level of information for forest inventories and research activities.

Aims

This dataset has been developed during the A2 Action (Assessment of structural and mensurational parameters of the forest stands and the dead wood) of the project, to record the main mensurational parameters of the studied black pine stands. A tree-level database was compiled to describe the vertical and horizontal structure of 54 monitoring plots before the application of the silvicultural treatment.

Methods

In addition to classical in-field measurements (e.g. diameters at breast height, total height of the tree, crown depth etc.), all trees were georeferenced by means of polar coordinates collected from the centre of each monitoring plot, including crown projection on the ground, described with eight points. Then, a polynomial spline function was fitted across the recorded data to obtain a convex polygon and to calculate crown area and crown perimeter of each measured tree in GIS environment.

Results

A polygonal ESRI shapefile in ETRS89/UTM32N reference system (EPSG: 25832) with 4171 records representing the crown projections on the ground of each measured tree with all the mensurational parameters included into the attribute table. The database is freely available under the Creative Commons Attribution-NonCommercial 4. 182 0 License.

Conclusion

With this database, a wide range of forestry-related indices could be easily calculated, including geostatistical analysis and autocorrelation functions, to compare Italian artificial black pine stands with other studied forests.

     

Response of white clover genotypes to evaluation environments of dense and spaced planting, and implications for selection

Twelve genotypes were grown for two years asmonocultures in the evaluation environments (EE) ofspaced planting (SP) and dense planting (DP). Drymatter (DM) yield, seed yield and their contributingtraits were recorded. The environments were comparedfor: i) genotype performance, and selection efficiencyfor the target environment of DP, and ii) estimates ofgenetic correlations between traits. DP was obtainedby close transplanting of clonal cuttings. EE × Ginteraction occurred for DM yield over harvests, andstolon density, petiole length, inflorescenceproduction and number of florets per inflorescence averagedover repeated measurements. Interaction effectsleading to relatively higher DM yield in SP tended tobe associated positively with those for the othertraits and featured the genotypes with greater abilityto colonize bare soil by stolon production. Theinteraction effects decreased with time and generallydisappeared (p < 0.05) by the end of the experiment,when the environments reached a similar DM yield andstolon density. EE × G interaction also occurred forseed yield (p < 0.08), recorded at the second year.Indirect selection in SP for performance in DP waspredicted to be less efficient for DM yield (–40%),seed yield (–23%) and the other traits subject to EE ×G interaction, compared with direct selection in DP.Evaluation under SP led to identification of severalgenetic correlations that were not confirmed under DP.DP compared with the traditional SP evaluationtechnique is more labour-demanding but allows for i)increasing the selection efficiency and/or decreasingthe time needed for a reliable evaluation, and ii)obtaining a more reliable estimation of geneticcorrelations for ordinary agricultural environments.     

Surface Properties of Gluten Investigated by a Fluorescence Approach

The surface properties of glutens isolated from a durum wheat cultivar (Capeiti) and two bread wheats (Riband and Hereward) were investigated using intrinsic and extrinsic fluorescence. Intrinsic fluorescence decreased on increasing protein concentration and increased after urea addition. The extrinsic fluorescence was evaluated by a titration with 8‐anilino‐1‐naphthalene sulphonate (ANS), an hydrophobic probe. The saturating concentration for ANS and its dissociation constant (Kd) were determined. The hydrophobicity of durum and bread wheat gluten showed a different behavior increasing the protein concentration: Capeiti was not influenced, but there was a change on the gluten surface for Riband and Hereward. The significance in understanding gluten structure and the relevance of the surface properties are discussed.     

Bird communities and extended biotic index (EBI) in some tributaries of the Tiber river

1. Riparian birds and macroinvertebrates were studied in five reaches of four tributaries of the Tiber river (Italy). The first aim was to check if stream quality, assessed by extended biotic index (EBI) values, could represent change in the riparian zone, assessed through the bird community. The second was to consider whether stream quality affects the presence of riverine bird species. 2. Stream quality and richness of the riparian bird community were related. In streams with more disturbed macroinvertebrate communities, but also in agricultural areas, the relative frequency of granivorous species increased in the riparian zone. 3. Dippers Cinclus cinclus occurred exclusively in reaches with the best stream quality, but the relationship between grey wagtails Motacilla cinerea and stream quality was less clear. 4. These results support the judicious use of riverine and riparian birds as biological indicators. Copyright © 1999 John Wiley & Sons, Ltd.     

Dual Targeting of PTP1B and Aldose Reductase with Marine Drug Phosphoeleganin: A Promising Strategy for Treatment of Type 2 Diabetes

An in-depth study on the inhibitory mechanism on protein tyrosine phosphatase 1B (PTP1B) and aldose reductase (AR) enzymes, including analysis of the insulin signalling pathway, of phosphoeleganin, a marine-derived phosphorylated polyketide, was achieved. Phosphoeleganin was demonstrated to inhibit both enzymes, acting respectively as a pure non-competitive inhibitor of PTP1B and a mixed-type inhibitor of AR. In addition, in silico docking analyses to evaluate the interaction mode of phosphoeleganin with both enzymes were performed. Interestingly, this study showed that phosphoeleganin is the first example of a dual inhibitor polyketide extracted from a marine invertebrate, and it could be used as a versatile scaffold structure for the synthesis of new designed multiple ligands.     

Assessing the potential of marine Natura 2000 sites to produce ecosystem‐wide effects in rocky reefs: A case study from Sardinia Island (Italy)

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Modelling the biomass yield and the impact of seabream mariculture in the Adriatic and Tyrrhenian Seas (Italy)

An individual-based model for Sparus aurata was developed, taking into account the effects on the growth rate of water temperature, food availability and diet composition. The model was identified on the basis of the recent literature regarding the physiological ecology of this species. It was subsequently calibrated and validated by using original field data collected at two Italian fish farms located, respectively, in the Adriatic and Tyrrhenian Seas. The mass budget of uneaten food and faeces was computed using the model at each farm: the optimal ingestion rate of a fish was computed based on its wet weight and the temperature of the water, while the faeces estimation considered the different digestibility of lipids, carbohydrates and proteins in the diet. From an applied perspective, the future use of this growth model in relation to mariculture site selection and monitoring might typically be to estimate both the yield and the amount of uneaten food and faeces discharged from a fish cage. This second output represents a useful input for deposition models which are routinely used in the field of mariculture monitoring by different EU countries. The integration of growth and deposition models in a single system could provide a useful tool for the site-selection and monitoring of finfish mariculture operations in Mediterranean environments.     

Physiological and biochemical adaptive traits support the specific breeding of alfalfa (Medicago sativa) for severely drought-stressed or moisture-favourable environments

The adaptation of alfalfa to moisture-favourable and drought-prone environments and its underlying mechanisms have not been thoroughly investigated despite their crucial importance to maximize the crop breeding progress. The main aim of this study was to support breeding strategies by exploring the relationship of leaf morphophysiological traits assessed in three growth chamber experiments with the adaptive response of five cultivars (Mamuntanas; Demnat 203; Erfoud 1; Prosementi; SARDI 10) that showed large genotype × environment interaction (GEI) across 10 drought-prone to moisture-favourable Mediterranean environments. Changes in shoot and root metabolite profiles across moisture-contrasting conditions were assessed for two cultivars with contrasting adaptation pattern. The cultivar specifically adapted to drought-prone environments (Mamuntanas), compared with that specifically adapted to moisture-favourable environments (Demnat 203), displayed: (i) lower leaf wilting under drought stress; (ii) delayed leaf senescence under stress, assessed as limited chlorophyll reduction either in vivo from upper to central leaves or in vitro from control to polyethylene glycol-treated leaflets, (iii) greater leaf tolerance to desiccation, measured in vitro as less pronounced reduction of leaf dry weight from control to polyethylene glycol-treated leaflets, (iv) smaller leaves, (v) lower early root and shoot growth and (vi) lower leaf stomata density. The other cultivars exhibited different combinations and/or intermediate values of these traits. The metabolite profiles of Mamuntanas and Demnat 203 differed more in shoots than in roots. Mamuntanas accumulated more amino acids than Demnat 203 under moisture-favourable and drought conditions. The distinct and partly incompatible combination of traits featuring the cultivars that maximized the crop yield in favourable or drought-prone conditions (Mamuntanas and Demnat 203) improves our understanding of traits contributing to large GEI across moisture-contrasting environments and support the breeding for specific adaptation to either condition. We identified a few inexpensive morphophysiological traits that could be used for early selection targeting drought-prone environments.