The increasing number of successful applications of fuzzy logic and fuzzy sets theory to dealing with the uncertainty, imprecision and subjectivity inherent to environmental quality assessments, and the recent development of new procedures based on fuzzy logic for the design of environmental quality indexes open new ways to carry out more rigorous and realistic estimations of soil quality. With these considerations in mind, the aim of this work is to design an index based on fuzzy logic, which is especially addressed to assess the dynamic quality of agricultural soils - Soil Dynamic Quality Index (S-DQI). This index is described by a group of three indexes (S-DQI(PHYS), S-DQI(CHEM), S-DQI(BIOL)), each one designed to evaluate the dynamic quality of agricultural soils with regard to their physical, chemical and biological characteristics, respectively. Each index is determined from the joint opinion of a panel of experts, which decides: (i) the attributes or properties of soil which determine its dynamic quality for farming; (ii) the most suitable indicator for quantifying each of them; (iii) the influence of the values taken by these indicators on the quality of agricultural soils, which is expressed by means of membership functions, and (iv) the relative importance of the attributes in the respective index, which is expressed by means of normalized priority vectors. The value of each of these indexes is finally obtained as a result of a fuzzy inference procedure, which is a crisp value ranging from 0 to 1. This procedure allows us to express the values taken by the indicators in a particular agroecosystem by means of both crisp values and fuzzy numbers, the latter being frequently a more rigorous and realistic way of representing the estimations of the soil properties in any emplacement. Verification tests show the satisfactory response capability of the index to changes in the soil properties. The use of the designed S-DQI for routine monitoring of the quality of farming soil allows the estimation of the changes induced in the soil due to use, which is helpful to assess systematically the sustainability of the agricultural practices. (C) 2015 Elsevier Ltd. All rights reserved.

For the first time in the literature, duckweed (Lemna minor) tolerance (alone or in combination with a consortium of bacteria) to spent metal-working fluid (MWF) was assessed, together with its capacity to reduce the chemical oxygen demand (COD) of this residue. In a preliminary study, L.minor response to pre-treated MWF residue (ptMWF) and vacuum-distilled MWF water (MWFw) was tested. Plants were able to grow in both residues at different COD levels tested (up to 2300mgl(-1)), showing few toxicity symptoms (mainly growth inhibition). Plant response to MWFw was more regular and dose responsive than when exposed to ptMWF. Moreover, COD reduction was less significant in ptMWF. Thus, based on these preliminary results, a second study was conducted using MWFw to test the effectiveness of inoculation with a bacterial consortium isolated from a membrane bioreactor fed with the same residue. After 5days of exposure, COD in solutions containing inoculated plants was significantly lower than in non-inoculated ones. Moreover, inoculation reduced +-tocopherol levels in MWFw-exposed plants, suggesting pollutant imposed stress was reduced. We therefore conclude from that L.minor is highly tolerant to spent MWF residues and that this species can be very useful, together with the appropriate bacterial consortium, in reducing COD of this residue under local legislation limits and thus minimise its potential environmental impact. Interestingly, the lipophilic antioxidant tocopherol (especially the sum of + isomers) proved to be an effective plant biomarker of pollution.

Endophytic plant growth-promoting bacteria (endophytes) were isolated from a variety of (pseudo)metallophytes growing in an abandoned Zn/Pb mine and then characterized according to their plant growth-promoting traits (i.e. ACC deaminase activity, IAA production, siderophore production, phosphate solubilising capacity, metal and salt tolerance and phenotypic characterization). Initially, under growth chamber conditions, an endophyte-assisted aided phytostabilization study was carried outwith Festuca rubra plants (native vs. commercial variety) inoculated with a Pseudomonas sp. isolate and cow slurry as organic amendment. The effect of treatments on soil physicochemical and microbial indicators of soil quality, as well as plant physiological parameters and metal concentrations, was assessed. We performed a complementary interpretation of our data through their grouping within a set of ecosystem services. Although the application of cow slurry had the most pronounced effects on soil quality indicators and ecosystem services, the growth of native F. rubra plants reduced soil bioavailability of Cd and Zn by 19 and 22%, respectively, and enhanced several soil microbial parameters. On the other hand, endophyte (Pseudomonas sp.) inoculation improved the physiological status of F. rubra plants by increasing the content of carotenoids, chlorophylls and Fv/Fm by 69, 65 and 37%, respectively, while also increasing the values of several soil microbial parameters. Finally, a consortium of five endophyte isolates was used for an endophyte-assisted aided phytostabilization field experiment, where lower metal concentrations in native excluder plants were found. Nonetheless, the field inoculation of the endophyte consortium had no effect on the biomass of native plants. (C) 2016 Elsevier B.V. All rights reserved.

In the north of Spain, Cortaderia selloana plants have invaded ecosystems of high ecological value. Control of this species is carried out with the application of glyphosate-based formulations. The aim of this work was to determine, under microcosm conditions, the short-term (2 months) effects of the application of a glyphosate-based herbicide (Roundup(R)) on C. selloana rhizosphere microbial communities. To this purpose, before and after the application of Roundup(R), several parameters that provide information on the biomass, activity and diversity of rhizosphere fungal and bacterial communities (enzyme activities, basal and substrate-induced respiration, potentially mineralizable nitrogen, nitrification potential rate, ergosterol content and community-level profiles with Biolog(TM) plates and ARISA) were determined. We observed a stimulation of some microbial parameters, in particular those related to fungal communities. Further research is needed to determine the long-term consequences of this short-term fungal stimulation for soil functioning.

Mountain elevation gradients are invaluable sites for understanding the effects of climate change on ecosystem function, community structure and distribution. However, relatively little is known about the impact on soil microbial communities, in spite of their importance for the functioning of the soil ecosystem. Previous studies of microbial diversity along elevational gradients were often limited by confounding variables such as vegetation, pH, and nutrients. Here, we utilised a transect in the Pyrenees established to minimise variation in such parameters, to examine prokaryotic, fungal, protist and metazoan communities throughout three consecutive years. We aimed to determine the influences of climate and environmental parameters on soil microbial community structure; as well as on the relationships between those microbial communities. Further, functional diversity of heterotrophic bacteria was determined using Biolog. Prokaryotic and fungal community structure, but not alpha-diversity, correlated significantly with elevation. However, carbon-to-nitrogen ratio and pH appeared to affect prokaryotic and protist communities more strongly. Both community structure and physicochemical parameters varied considerably between years, illustrating the value of long-term monitoring of the dynamic processes controlling the soil ecosystem. Our study also illustrates both the challenges and strengths of using microbial communities as indicators of potential impacts of climate change.

Mining sites shelter a characteristic biodiversity with large potential for the phytoremediation of metal contaminated soils. Endophytic plant growth-promoting bacteria were isolated from two metal-(hyper)accumulator plant species growing in a metal contaminated mine soil. After characterizing their plant growth-promoting traits, consortia of putative endophytes were used to carry out an endophyte-assisted phytoextraction experiment using Noccaea caerulescens and Rumex acetosa (singly and in combination) under controlled conditions. We evaluated the influence of endophyte-inoculated plants on soil physicochemical and microbial properties, as well as plant physiological parameters and metal concentrations. Data interpretation through the grouping of soil properties within a set of ecosystem services was also carried out. When grown together, we observed a 41 and 16% increase in the growth of N. caerulescens and R. acetosa plants, respectively, as well as higher values of Zn phytoextraction and soil microbial biomass and functional diversity. Inoculation of the consortia of putative endophytes did not lead to higher values of plant metal uptake, but it improved the plants' physiological status, by increasing the content of chlorophylls and carotenoids by up to 28 and 36%, respectively, indicating a reduction in the stress level of plants. Endophyte-inoculation also stimulated soil microbial communities: higher values of acid phosphatase activity (related to the phosphate solubilising traits of the endophytes), bacterial and fungal abundance, and structural diversity. The positive effects of plant growth and endophyte inoculation on soil properties were reflected in an enhancement of some ecosystem services (biodiversity, nutrient cycling, water flow regulation, water purification and contamination control)

Construction of Technosols offers interesting alternatives to two current problems in the city of VitoriaGasteiz

(Spain): waste recycling and degraded plot recovery. To evaluate the viability of their use, 6

types of Technosols were created by mixing four different byproducts from municipal waste treatment

plants. The less than 40 mm size fraction material from the municipal construction and demolition waste

treatment plant was used as the main ingredient, bio-stabilized material from the solid urban waste

treatment plant mixed with triturated pruning was used as organic matter input, recycled bentonites and

topsoil from the public plots of Vitoria-Gasteiz (Spain) completed the mixture. Mixes were prepared

in triplicate and installed in 48 m2

cells along with another 4 control cells containing only one of the

ingredients at the municipal landfill of Gardelegui. A monitoring program for different parameters on

soil, eluates and natural leachates was established to test the Technosols’ capacity to sustain vegetation

without negative impacts on the environment. The final objective is to test their ability to restore unused

municipal plots. Results from the first year show that Technosols are a suitable option for degraded sites

restoration and green infrastructure support. All controlled parameters on soil are within the limits set by

autonomic legislation for land use as public park. The eluate analysis concludes for all studied parameters

that all mixes would be classified by legislation as inert waste, except for the sulphate concentration

(which exceeds the inert waste limit of 1 000 ppm), that currently would label the soil as non-hazardous.

In the natural leachate analysis strongly basic pH values were present above 9.5, the limit allowed in

Royal Decreet 849/1986, but acidified throughout the year moving towards neutrality, with final values

between 7.31 and 7.51. Leachate from CDW30, TS15 and RB30 Technosols showed not allowed values

with respect to sulfates and Fe during the last sampling, surpassing the limits of 2 mg/l and 2 000 mg/l

respectively. All studied Technosols presented a low ecological potential risk (RI < 150) for heavy metals

in soil and eluates.

Carotenoids constitute a major target of chloroplastic photooxidative reactions, leading to the formation of several oxidized derivatives and cleavage products, some of which are volatile (VCCPs). Among them, beta-cyclocitral (beta-CC), at least, is a retrograde signaling molecule that modulates the activity of many key physiological processes. In the present work, we aimed to study whether beta-CC and other VCCPs are released into the atmosphere from photosynthetic tissues. To overcome stomatal limitations, the foliose chlorolichen Lobaria pulmonaria was used as the model system, and the emissions of biogenic volatiles, induced by heat and wounding stresses, were monitored by proton-transfer reaction time-of-flight mass spectrometry (PTR-TOF-MS) and gas-chromatography (GC-MS). Prior to stress treatments, VCCPs were emitted constitutively, accounting for 1.3% of the total volatile release, with beta-CC being the most abundant VCCP. Heat and wounding stresses induced a burst of volatile release, including VCCPs, and a loss of carotenoids. Under heat stress, the production of beta-CC correlated positively with temperature. However the enhancement of production of VCCPs was the lowest among all the groups of volatiles analyzed. Given that the rates of carotenoid loss were three orders of magnitude higher than the release rates of VCCPs and that these compounds only represent a minor fraction in the blend of volatiles, it seems unlikely that VCCPs might represent a global stress signal capable of diffusing through the atmosphere to different neighboring individuals.