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Forests are among the most important land ecosystems both in term of their contribution to the global carbon cycle and for their prominence in hosting large biodiversity. Under a changing world, both in terms of land use and climate scenarios, it is pivotal to understand the matter and energy flows in complex ecosystems such as forests, in order to infer potential relationships at different levels, i.e. from soil to bird community within the forest stands. In this context, soil organic matter is main source of carbon and energy for heterotrophic soil organisms, which are a main component of the whole food web all the way up to bird communities. Even though many studies have investigated factors affecting C cycle and bird communities in forest ecosystems separately, an integrated approach that links soil to bird community was never attempted. Accordingly, we have used an innovative Two-block Partial Least Squares analysis to investigate patterns of covariance between soil and nesting bird communities in a relatively small wooded area surrounded by the urban area of Naples (southern Italy). Our research revealed that, in spite of the small extent and the surrounding urban context, the area of the Astroni hosts a substantial C stock and has a diversified bird nesting community. The abundance of species such as blue tit, jay, green woodpecker and great tit had a direct covariance with C stock in litter, while sampling sites that were characterized by greater C stocks in the soil and higher microbial activity were correlated with abundance of other bird species, most noticeably short-toed treecreeper and blackbird. Despite the limited extent of our research area, our study showed, for the first time, patterns of covariance between some forest species and different soil variables, linking forest ecological compartments whose connections are not immediately detectable and that could open new perspectives in land use management, both in terms of C stock and biodiversity evaluations.

Trace elements have been acknowledged as one of the subtlest environmental hazards in all compartments of the total environment. Enhanced by activities in the anthroposphere, they accumulate in the atmosphere, lithosphere, and hydrosphere. Eventually, trace elements can bioaccumulate or biomagnifiy in the biosphere, with harmful effects on animals occupying higher trophic levels, including humans. Accordingly, there is great interest in assessing and monitoring trace element concentrations in the biosphere, and birds, especially passerines, have been commonly chosen as biomonitors. In this study, the concentration of 11 trace elements was measured (i.e. aluminum, chromium, manganese, iron, nickel, copper, zinc, arsenic, cadmium, barium, and lead) in flight feathers of Italian Sparrows, a common bird species hitherto not analysed in this respect. Samples were collected in an agricultural area in southern Italy, where a mosaic of natural environments, urbanized areas and industrial facilities can be found. Linear mixed modelling was applied to the analysis of flight feathers in juveniles, juvenile birds moulting to adulthood, and adults in three sampling years on 184 birds. Results are timely as they add new data to the scarce available information on Ba and As in bird feathers and showed clear bioaccumulation patterns from juveniles to adults for As, Cr, and Cd. Moreover, the modelling approach showed that the concentration of elements such as As, Cd and Cr can be variable across the years and that some elements, notably Cd and Ba, were inversely correlated with body mass and wing length, respectively, suggesting potential negative effects on bird health. Finally, when modelling bird body condition and trace elements, results showed that Cd and Ba negatively affect birds regardless of age or sampling year. Thus, the Italian Sparrow could be considered as a valuable biomonitor for trace elements in the total environment, especially for Cd and Ba.

Agricultural soils generally have a low content of organic matter, which affects soil fertility and hence crop yields. The use of olive pomace as an organic amendment could enhance soil properties due to its high content of organic matter and exchangeable cations as well as its extensive availability. However, little is known about the potentially detrimental effects of salts and high content of phenolic substances that might occur over time with the use of pomace amendment in agricultural soils. Similarly, its impact on microbial communities and enzyme activities is largely unknown. To ascertain these effects, we tested the response of soil enzyme activities (β-glucosidase, urease, acid phosphomonoesterase and dehydrogenase) starting from a long-term (8-year) previously amended soil and a control (non-amended) soil and exposing these soils to a short-term (12-week) laboratory experiment. We also focused on soil organic matter and mineral N, on relating enzymatic data to bacterial and fungal biomasses, and on an index for soil functional quality based on enzyme activities (AI3). Our results show that organic matter, enzyme activities and the soil quality index were improved by long-term treatment with olive pomace, contrasting with scant effects from short-term laboratory incubation. In spite of its high content in salts and phenolic substances, no detectable negative impact emerged from the use of this amendment. Overall, olive pomace clearly increased soil organic matter and improved soil biological activity and quality, without any detectable negative effects.