Nutrient pollution has increased plant litter nutrient concentrations in many ecosystems, which may profoundly impact litter decomposition and change the chemical composition of litter inputs to soils. Here, we report on a mesocosm experiment to study how variations in the nitrogen (N) and phosphorus (P) concentrations in Fagus sylvatica (European beech) litter from four sites differing in bedrock, atmospheric deposition, and climate affect lignin and carbohydrate loss rates and residual litter chemistry. We show with pyrolysis GC/MS and elemental analysis that nutrient concentrations had a strong influence on changes in litter chemistry during early decomposition (0–181 days), when greater lignin loss rates were associated with low P concentrations, whereas carbohydrate and bulk C loss were associated with high N concentrations. Nutrient concentrations, in contrast, did not influence changes in litter chemistry in the later decomposition stage (181–475 days), where the decomposition rates of lignin, carbohydrates, and bulk C all increased with litter N concentration and no differences in decomposition rates between major compound classes were detected. Our data indicate that these differences were related to the transition from increasing to constant or declining microbial biomass, and an associated decrease in microbial dependence on the mobilization of nutrients from the insoluble litter fraction.

Aquatic ecosystems often act as sinks for agricultural, industrial, and urban wastes. Among potential pollutants, heavy metals can modify major biogeochemical cycles by affecting microorganisms and other biota. This study assessed the distribution and concentration of heavy metals (Cd, Hg, Cu, Pb, and Zn) in Pétrola Lake, a heavily impacted area in central Spain where the greater flamingo Phoenicopterus roseus breeds. This study was designed to determine the concentration and identify the potential sources of heavy metals in Pétrola Lake protected area, including sediments, agricultural soils, and tissues of the greater flamingo. A six-step sequential extraction was performed to fractionate Cu, Pb, and Zn from lake sediments and agricultural soil samples to gain insight into different levels of their bioavailability. Our results showed that Pb and Cd accumulated in lake sediments and agricultural soils, respectively, most likely derived from anthropogenic sources. Multivariate analysis revealed differences between these (Pb and Cd) and the remaining studied elements (Cu, Hg, and Zn), whose concentrations were all below the pollution threshold. Lead pollution in sediments was apparently dominated by organic matter binding, with fractions up to 34.6% in lake sediments. Cadmium slightly accumulated in agricultural soils, possibly associated with the use of fertilizers, but still below the pollution thresholds. In the flamingo samples, low bioaccumulation was observed for all the studied elements. Our study suggests that human activities have an impact on heavy metal accumulation in sediments and soils, despite being below the pollution levels.

Amyotrophic lateral sclerosis (ALS), a devastating progressive neurodegenerative disease, has no effective treatment. Recent evidence supports a strong metabolic component in ALS pathogenesis. Indeed, metabolic abnormalities in ALS correlate to disease susceptibility and progression, raising additional therapeutic targets against ALS. Ozone (O3), a natural bioactive molecule, has been shown to elicit beneficial effects to reduce metabolic disturbances and improved motor behavior in TDP-43A315T mice. However, it is fundamental to determine the mechanism through which O3 acts in ALS. To characterize the association between O3 exposure and disease-associated weight loss in ALS, we assessed the mRNA and protein expression profile of molecular pathways with a main role in the regulation of the metabolic homeostasis on the hypothalamus and the brown adipose tissue (BAT) at the disease end-stage, in TDP-43A315T mice compared to age-matched WT littermates. In addition, the impact of O3 exposure on the faecal bacterial community diversity, by Illumina sequencing, and on the neuromuscular junctions (NMJs), by confocal imaging, were analysed. Our findings suggest the effectiveness of O3 exposure to induce metabolic effects in the hypothalamus and BAT of TDP-43A315T mice and could be a new complementary non-pharmacological approach for ALS therapy.