Relationships between vegetation patterns and periglacial landforms in northwestern Svalbard

We studied the small-scale vegetation pattern in the high Arctic at Ny Angstromlesund to assess if the plant distribution was related to periglacial landforms. The whole area has been deglaciated for millennia but only a modest part of the area was covered by mature vegetation. The plant cover varied considerably in relation to ground patterning originated by periglacial processes, especially frost heave, frost creep, gelifluction and ice segregation, giving rise to a mosaic of microhabitats sharply differing from each other as regards physical properties and microclimate. The distributional patterns of vascular plants, lichens and bryophytes were primarily affected by complex responses to substrate texture, soil moisture content and substrate disturbance. Since global warming will probably affect both periglacial processes and plant responses to altered habitat conditions, we concluded that long-term monitoring of relationships between landforms and vegetation represents a suitable tool for assessing the impact of global change on arctic regions

Intraspecific functional trait response to advanced snowmelt suggests increase of growth potential but decrease of seed production in snowbed plant species

In ecological theory, it is currently unclear if intraspecific trait responses to environmental variation are shared across plant species. We use one of the strongest environmental variations in alpine ecosystems, i.e., advanced snowmelt due to climate warming, to answer this question for alpine snowbed plants. Snowbeds are extreme habitats where long-lasting snow cover represents the key environmental factor affecting plant life. Intraspecific variation in plant functional traits is a key to understanding the performance and vulnerability of species in a rapidly changing environment. We sampled snowbed species after an above-average warm winter to assess their phenotypic adjustment to advanced snowmelt, based on differences in the natural snowmelt dynamics with magnitudes reflecting predicted future warming. We measured nine functional traits related to plant growth and reproduction in seven vascular species, comparing snowbeds of early and late snowmelt across four snowbed sites in the southern Alps in Italy. The early snowbeds provide a proxy for the advanced snowmelt caused by climatic warming. Seed production was reduced under advanced snowmelt in all seed-forming snowbed species. Higher specific leaf area (SLA) and lower leaf dry matter content (LDMC) were indicative of improved growth potential in most seed-forming species under advanced snowmelt. We conclude, first, that in the short term, advanced snowmelt can improve snowbed species’ growth potential. However, in the long term, results from other studies hint at increasing competition in case of ongoing improvement of conditions for plant growth under continued future climate warming, representing a risk for snowbed species. Second, a lower seed production can negatively affect the seed rain. A reduction of propagule pressure can be crucial in a context of loss of the present snowbed sites and the formation of new ones at higher altitudes along with climate warming. Finally, our findings encourage using plant functional traits at the intraspecific level across species as a tool to understand the future ecological challenges of plants in changing environments

Refugial peatlands in the Northern Apennines. Vegetation-environment relationships and future perspectives

Aims: We aimed to detect the environmental drivers conditioning plant diversity and to predict how modifications in habitat conditions and ongoing global warming could lead to vegetation changes or biodiversity losses in a region especially rich in peatlands despite its relatively low latitude. Study area: The study area was located in the Northern Apennines, Northern Italy (about 44 degrees 45' N; 10 degrees 20' E). The vegetation study was carried out at 12 peatland sites where 206 plots were set up. Species composition in the 206 plots were recorded in the field and classified with cluster analysis. Data on hydrology, water chemistry and peat chemistry were collected at a subset of 127 plots and statistically analysed by a multivariate ordination method. Species richness and evenness were calculated for all plots. Relationships between species composition and environmental variables were analysed by stepwise multiple regression. Results: The cluster analysis defined 17 vegetation units. Water table depth represented the major environmental factors accounting for vegetation patterns, with the vegetation units being grouped in four main blocks based on vegetation physiognomy and species composition: Sphagnum hummocks, Sphagnum lawns, fens and pools. Water chemistry and peat chemistry both presented moderate variations among the vegetation units with mean water pH ranging from 4.9 to 6.3. Concentrations of major cations in the pore water showed that all of the habitats investigated were influenced by telluric water, with no evidence of ombrotrophic conditions. Species richness and evenness both presented poor relations with the environment while responses of individual species to environmental factors were more informative on vegetation changes triggered by climate change. Conclusions: Prolonged drought events associated with high temperature in summer months are expected to exert a strong impact on peatland vegetation. The main effect of climate change on the vegetation of the peatlands investigated consists in the spreading of vascular plants at the expense of Sphagnum mosses

Plant Regeneration Above the Species Elevational Leading Edge: Trade-Off Between Seedling Recruitment and Plant Production

Mountains and their biota are highly threatened by climate change. An important strategy that alpine plants use to escape this change consists in seed dispersal and the ability of seeds to germinate and establish in new sites at higher elevation. Little is known about the environmental factors that can affect the regeneration of plants above the elevational limit of growth. We present the first field evidence of recruitment success and plant performance in consequence of upward shift from the alpine to the nival life zone. Seeds of four alpine grassland species were sown at the current elevational limit of growth (site A) and 200 m upward, in a nival environment (site N) located in the Italian Alps. At site N part of the seeds were subjected to experimental manipulation of temperature (using an Open Top Chamber, OTC) or soil (using soil from site A). Recruitment success, soil surface temperature and water potential were monitored for five consecutive years. At the end of the experiment, vegetative growth and foliar traits were measured on individuals from all treatments. Mean annual soil surface temperature and length of the growing season at site A were ca. 2°C higher and ca. 44 days longer than at site N. Seedling emergence and seedling establishment generally were higher at N (with or without OTC) on local soil than at site A or at site N with soil originating from site A. Conversely, production was higher at site A and at site N with soil originating from site A. Recruitment success above the elevational leading edge was enhanced by coarser and nutrient-poor soil, which promoted seedling emergence and establishment but constrained plant growth. This trade-off between seedling recruitment and plant production underlines adaptive consequence and environmental filtering, both critical to forecast community assembly and responses of alpine species to climate warming

Amyotrophic Lateral Sclerosis and Air Pollutants in the Province of Ferrara, Northern Italy: An Ecological Study

The etiopathogenesis of amyotrophic lateral sclerosis (ALS) is still largely unknown, but likely depends on gene-environment interactions. Among the putative sources of environmental exposure are air pollutants and especially heavy metals. We aimed to investigate the relationship between ALS density and the concentration of air pollution heavy metals in Ferrara, northern Italy. An ecological study was designed to correlate the map of ALS distribution and that of air pollutants. All ALS cases diagnosed between 2000 and 2017 (Ferrara University Hospital administrative data) were plotted by residency in 100 sub-areas, and grouped in 4 sectors: urban, rural, northwestern and along the motorway. The concentrations of silver, aluminium, cadmium, chrome, copper, iron, manganese, lead, and selenium in moss and lichens were measured and monitored in 2006 and 2011. Based on 62 ALS patients, a strong and direct correlation of ALS density was observed only with copper concentrations in all sectors and in both sexes (Pearson coefficient (ρ) = 0.758; p = 0.000002). The correlation was higher in the urban sector (ρ = 0.767; p = 0.000128), in women for the overall population (ρ = 0.782, p = 0.000028) and in the urban (ρ = 0.872, p = 0.000047) population, and for the older cohort of diagnosed patients (2000-2009) the assessment correlated with the first assessment of air pollutants in 2006 (ρ = 0.724, p = 0.008). Our data is, in part, consistent with a hypothesis linking copper pollution to ALS

Lysozyme-induced transcriptional regulation of tnf-\u3b1 pathway genes in cells of the monocyte lineage

Lysozyme is one of the most important anti-bacterial effectors in the innate immune system of animals. Besides its direct antibacterial enzymatic activity, lysozyme displays other biological properties, pointing toward a significant anti-inflammatory effect, many aspects of which are still elusive. Here we investigate the perturbation of gene expression profiles induced by lysozyme in a monocyte cell line in vitro considering a perspective as broad as the whole transcriptome profiling. The results of the RNA-seq experiment show that lysozyme induces transcriptional modulation of the TNF-\u3b1/IL-1\u3b2 pathway genes in U937 monocytes. The analysis of transcriptomic profiles with IPA\uae identified a simple but robust molecular network of genes, in which the regulation trends are fully consistent with the anti-inflammatory activity of lysozyme. This study provides the first evidence in support of the anti-inflammatory action of lysozyme on the basis of transcriptomic regulation data resulting from the broad perspective of a whole-transcriptome profiling. Such important effects can be achieved with the supplementation of relatively low concentrations of lysozyme, for a short time of exposure. These new insights allow the potential of lysozyme in pharmacological applications to be better exploited

Metal-macrofauna interactions determine microbial community structure and function in copper contaminated sediments

Peer reviewedPublisher PD

Kosteletzkya pentacarpos (L.) Ledeb.

Viene definita la distribuzione in Italia di Kosteletzkya pentacarpos e discusso il suo stato di conservazione

Surface Covering of Downed Logs: Drivers of a Neglected Process in Dead Wood Ecology

Many species use coarse woody debris (CWD) and are disadvantaged by the forestry-induced loss of this resource. A neglected process affecting CWD is the covering of the surfaces of downed logs caused by sinking into the ground (increasing soil contact, mostly covering the underside of the log), and dense overgrowth by ground vegetation. Such cover is likely to profoundly influence the quality and accessibility of CWD for wood-inhabiting organisms, but the factors affecting covering are largely unknown. In a five-year experiment we determined predictors of covering rate of fresh logs in boreal forests and clear-cuts. Logs with branches were little covered because they had low longitudinal ground contact. For branchless logs, longitudinal ground contact was most strongly related to estimated peat depth (positive relation). The strongest predictor for total cover of branchless logs was longitudinal ground contact. To evaluate the effect on cover of factors other than longitudinal ground contact, we separately analyzed data from only those log sections that were in contact with the ground. Four factors were prominent predictors of percentage cover of such log sections: estimated peat depth, canopy shade (both increasing cover), potential solar radiation calculated from slope and slope aspect, and diameter of the log (both reducing cover). Peat increased cover directly through its low resistance, which allowed logs to sink and soil contact to increase. High moisture and low temperatures in pole-ward facing slopes and under a canopy favor peat formation through lowered decomposition and enhanced growth of peat-forming mosses, which also proved to rapidly overgrow logs. We found that in some boreal forests, peat and fast-growing mosses can rapidly cover logs lying on the ground. When actively introducing CWD for conservation purposes, we recommend that such rapid covering is avoided, thereby most likely improving the CWD's longevity as habitat for many species