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A common view is that honeybees are mostly managed by beekeepers for commercial purposes or as a hobby, especially in Europe. This misconception is probably due to the lack of systematic studies on wild colonies of honeybees in Europe in comparison to other regions of the world. Since we are used to considering this species as “domesticated”, we may be induced to disregard activities not distinctly linked with colony survival, reproduction, or productivity. Washboarding is one of them in which the entire colony stops resource collection activities; numerous individual bees assemble on the front side of the hive and perform repetitive movements back and forth. They are curiously synchronised but apparently without a scope. In this exploratory work, we carried out a literature review of available, mostly grey, literature. Assuming this behaviour may be linked to cavity-nesting and to tree trunks or rocks being rough surfaces hosting various cryptogams, we performed preliminary observations and manipulative experiments. From our survey, we depict that washboarding is frequently reported in grey literature/beekeepers’ reports, but rarely mentioned in scientific literature. Beekeepers who responded to a designed questionnaire observed this behaviour in various ecological situations, with no trend emerging. Our preliminary experiment of placing cryptogams in front of managed hives resulted in honeybees removing lichens (foliose types) or covering with propolis, and all species were affected. Further research is needed to clarify if lichens are removed because of their chemical compounds, because of hosting potentially toxic microorganisms, or collected as resources.

The adoption of innovative cultivation methods, such as hydroponics and aeroponics, is gaining attention due to the unprecedented demand for food that an increasing population is posing on agricultural systems, exacerbating the pressure on already limited arable land. Seeking sustainable and circular economy solutions is imperative, aiming to optimize water consumption and enhance crop yields and quality without resorting to synthetic chemical fertilizers. This study investigated the use of seawater at various concentrations as a base for nutrient solutions, with and without the addition of a natural biostimulant, wood distillate (WD). Four seawater (SW) concentrations (0, 3, 6, and 12%) and two wood distillate concentrations (0 and 0.2%) were applied to assess their impacts on lettuce growth. Findings reveal that seawater at low concentrations (< 6%) serves as an effective water-saving strategy, despite the reduction in the plant ascorbic acid contents. The addition of WD did not inflate growth; in fact, the results obtained are comparable to that of the controls for each concentration of seawater, except at the highest concentration (12% SW), resulting in reduced fresh leaf weights and root areas. Significantly, there was a notable increase in the ascorbic acid contents in all plants grown with WD. Moreover, the WD increased the leaf concentrations in Ca, Mg, P, and K, indicating the higher nutritional value of the crop. This research highlights the potential of combining seawater and WD for sustainable and efficient plant cultivation, suggesting new strategies for exploration across diverse plant species and hydroponic applications. [ABSTRACT FROM AUTHOR]

The addition of biostimulants to nutrient solutions of hydroponically grown crops to speed up plant growth and improve plant yield and quality has been attracting more and more attention. This study investigated the effects of wood distillate (WD) addition to hydroponically grown lettuce (Lactuca sativa L.) plants. Two concentrations of WD, 0.2% and 0.5%, were added to the nutrient solution, and biometric (i.e., leaf fresh weight, root fresh weight, root length and root surface area), photosynthetic (i.e., chlorophyll a, chlorophyll b, and carotenoid content) and biochemical (i.e., electrolyte leakage, total polyphenols, total flavonoids, and total antioxidant power content) parameters were evaluated. The effects of WD were hormetic, as the 0.2% concentration stimulated biometric and biochemical parameters, while the 0.5% concentration inhibited plant growth. Based on these results, it can be suggested that the addition of 0.2% WD to the nutrient solution has a stimulating effect on the growth of lettuce plants, and could be a successful strategy to boost the yield of crops grown hydroponically. [ABSTRACT FROM AUTHOR]

Seed priming with synthetic chemicals may be harmful to the environment and human health. Their replacement with bio-based compounds may overcome these concerns. In this study, we assessed the effectiveness of wood distillate (WD) in enhancing in vitro germination of crop plants using basil, chickpea, and lettuce as case studies. Seeds of the three species were soaked for 24 h in 0.25% and 0.17% WD solutions and then left to germinate for 7 days at 20 °C in a dark germination chamber. Seed pre-treatment with 0.25% WD enhanced germination in all tested species, while 0.17% WD stimulated germination in lettuce and chickpea, but not in basil. For lettuce, 0.17% WD worked better than 0.25% WD. Radicle length of basil and chickpea increased following pre-treatment with 0.25% WD, while in lettuce, it increased after pre-treatment with 0.17% WD. Treating seeds with appropriate WD solutions is a potential strategy to improve germination of crop plants. [ABSTRACT FROM AUTHOR]

iNaturalist is a widely-utilized platform for data collection and sharing among non-professional volunteers and is widely employed in citizen science. This platform's data are also used in scientific studies for a wide range of purposes, including tracking changes in species distribution, monitoring the spread of alien-invasive species, and assessing the impacts of urbanization and land-use change on biodiversity. Lichens, due to their year-round presence on trees, soil and rocks, and their diverse shapes and colours, have captured the attention of iNaturalist users, and lichen records are widely represented on the platform. However, due to the complexity of lichen identification, the use of data collected by untrained, or poorly trained volunteers in scientific investigation poses concerns among lichenologists. To address these concerns, this study assessed the reliability of lichen identification by iNaturalist users by comparing records on the platform with identifications carried out by experts (experienced lichenologists) in three cities where citizen science projects were developed. Results of this study caution against the use of unchecked data obtained from the platform in lichenology, demonstrating substantial inconsistency between results gathered by iNaturalist users and experts. [ABSTRACT FROM AUTHOR]

In the quest for eco‐friendly products with biostimulant properties, foliar application of wood distillate (WD) was tested on the growth and yield of chickpea (Cicer arietinum L.). WD (pyroligneous acid) is a by‐product of plant biomass pyrolysis and is rich in biologically active substances like polyphenols, alcohols, acids and esters. In this work, chickpea plants were sprayed weekly with 100 ml 0.25% (v/v) chestnut (Castanea sativa Mill.) WD during the whole growing period, and at the end physiological and nutritional analyses were performed both on the whole plant and on seeds. While plant height and weight did not change significantly, seeds showed an increase in diameter (+11.2%) and weight (+33.3%), and in the content of starch (+45.9%), total soluble protein (+12.9%), total polyphenol (+16.4%) and antioxidant power (+28.4%). Overall, the content of essential free amino acids increased, except for lysine (−3.4%), phenylalanine (−10.5%) and methionine (−13.7%). Among all the mineral elements analysed, only potassium and magnesium decreased in WD‐treated plants, although values were within the common range for chickpea seeds. These results are a clear demonstration of the effectiveness of the use of WD on increasing the nutritional qualities of the edible parts of crop species, thus representing a possible solution to counteract human malnutrition and famine as well as environmental concerns. [ABSTRACT FROM AUTHOR]

Definition: Lichens have long been considered as composite organisms composed of algae and/or cyanobacteria hosted by a fungus in a mutualistic relationship. Other organisms have been gradually discovered within the lichen thalli, such as multiple algal species, yeasts, or even viruses. Of pivotal relevance is the existence of the lichen microbiome, which is a community of microorganisms that can be found living together on the lichen surface. This community performs a growing number of functions. In this entry, we explore the journey of lichens being considered from a dual partnership to a multi-species symbiotic relationship. [ABSTRACT FROM AUTHOR]

Climate change and atmospheric nitrogen (N) deposition on drylands are greatly threatening these especially vulnerable areas. Soil biocrust-forming lichens in drylands can provide early indicators of these disturbances and play a pivotal role, as they contribute to key ecosystem services. In this study, we explored the effects of different long-term water availability regimes simulating climate changes and their interaction with N addition on the physiological response of the soil lichen Cladonia rangiferina. Three sets of this lichen were subjected to control, reduced watering, and reduced watering and N addition (40 kg NH4NO3 ha−1 year−1) treatments for 16 months. Finally, all samples were subjected to daily hydration cycles with N-enriched water at two levels (40 and 80 kg NH4NO3 ha−1 year−1) for 23 days. We found that reduced watering significantly decreased the vitality of this lichen, whereas N addition unexpectedly helped lichens subjected to reduced watering to cope with stress produced by high temperatures. We also found that long-term exposure to N addition contributed to the acclimation to higher N availability. Overall, our data suggest that the interactions between reduced watering and increased N supply and temperature have an important potential to reduce the physiological performance of this soil lichen. [ABSTRACT FROM AUTHOR]

Lichens are classified into different functional groups depending on their ecological and physiological response to a given environmental stressor. However, knowledge on lichen response to the synergistic effect of multiple environmental factors is extremely scarce, although vital to get a comprehensive understanding of the effects of global change. We exposed six lichen species belonging to different functional groups to the combined effects of two nitrogen (N) doses and direct sunlight involving both high temperatures and ultraviolet (UV) radiation for 58 days. Irrespective of their functional group, all species showed a homogenous response to N with cumulative, detrimental effects and an inability to recover following sunlight, UV exposure. Moreover, solar radiation made a tolerant species more prone to N pollution’s effects. Our results draw attention to the combined effects of global change and other environmental drivers on canopy defoliation and tree death, with consequences for the protection of ecosystems. [ABSTRACT FROM AUTHOR]

An ecological biogeographical perspective provides an understanding of the factors that shape the geographical distribution of organisms, their biodiversity and ecological speciation. Focusing on members of the lichen genus Solenopsora , which are strongly linked to a Mediterranean-type climate, we aimed to depict their environmental niches in the Apennine Peninsula. This area represents their ecological optima, as well as the biogeographical centre of distribution. On the basis of occurrences of Solenopsora congeners, we identified the key ecological factors that shape their environmental niches. Applying an ensemble approach, which merges the results of Random Forest, GLM and MaxEnt algorithms, suitability maps were developed. These are mainly influenced by geological substratum, temperature and precipitation. Occurrence of Solenopsora taxa seems to be mainly governed by low variability in diurnal temperature and tolerance to dryness, with precipitation in the range of 0–20 mm in the driest month and a minimum temperature of >5 °C in the coldest month. The sensitivity to diurnal temperature, an important indicator for climate change, suggests that the taxa confined to Mediterranean bioclimatic types (i.e. Solenopsora grisea , S. marina , S. olivacea subsp. olbiensis and S. olivacea subsp. olivacea) might be good indicators of climatic stability. The geological substratum was a strong limiting factor and separated the taxa into three groups: those growing on calcareous, siliceous and ultramafic substrata. Limited co-occurrence of species confined to one of the three categories suggests that the level of niche differentiation is on a microhabitat level. Accounting for ecological requirements, the taxa differ in their tolerance to sub-optimal conditions. The ecological niches of a sister subspecies pair with different reproduction strategies, fertile S. olivacea subsp. olivacea and sorediate S. olivacea subsp. olbiensis , overlap strongly. However, habitat suitability for S. olivacea subsp. olbiensis is greater in areas with higher precipitation in the driest month, whereas S. olivacea subsp. olivacea is more restricted to warmer and drier areas. We also report new regional records for Italy and the first records of S. cesatii in Serbia and Ukraine, and of S. liparina in Serbia. [ABSTRACT FROM AUTHOR]

In this paper, we investigated whether growth form and substrate in lichens influence their physiological responses along an aridity gradient. Thalli of the foliose lichen Parmotrema perlatum and the fruticose lichen Ramalina canariensis were transplanted in selected rural/forested sites of Southern Portugal characterized by a different aridity index. Physiological parameters including photosynthetic performances, assimilation pigments, ergosterol content and sample viability were measured prior to exposure (winter) and after 6-month exposure (summer). Photosynthetic performances were also investigated in common native foliose and fruticose epiphytic lichens and in fruticose terricolous species. Both transplanted and native lichens showed a decrease in photosynthetic performances in summer and lower performances in sites classified as drier and higher performances in humid forested sites. No relevant differences occurred between epiphytic foliose and fruticose growth forms. However, terricolous fruticose samples showed a significant difference in humid and drier sites and between winter and summer, probably due to microclimatic conditions similarly to other biological crusts. [ABSTRACT FROM AUTHOR]

Soils are being degraded at an alarming rate and thereby also crucial ecosystem goods and services. Nitrogen (N) enrichment is a major driver of this degradation. While the negative impacts of N enrichment on vegetation are well known globally, those on various ecological interactions, and on ecosystem functioning, remain largely unknown. Because Mediterranean ecosystems are N limited, they are good model systems for evaluating how N enrichment impacts not only vegetation but also ecological partnerships and ecosystem functioning. Using a 7-year N-manipulation (dose and form) field experiment running in a Mediterranean Basin maquis located in a region with naturally low ambient N deposition (<4 kg N ha−1 y−1), we assessed the impacts of the N additions on (i) the dominant plant species (photosynthetic N-use efficiency); (ii) plant-soil ecological partnerships with ectomycorrhiza and N-fixing bacteria; and (iii) ecosystem degradation (plant-soil cover, biological mineral weathering and soil N fixation). N additions significantly disrupted plant-soil cover, plant-soil biotic interactions, and ecosystem functioning compared with ambient N deposition conditions. However, the higher the ammonium dose (alone or with nitrate), the more drastic these disruptions were. We report a critical threshold at 20-40 kg ammonium ha−1 y−1 whereby severe ecosystem degradation can be expected. These observations are critical to help explain the mechanisms behind ecosystem degradation, to describe the collective loss of organisms and multifunction in the landscape, and to predict potential fragmentation of Mediterranean maquis under conditions of unrelieved N enrichment. Copyright © 2017 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Atmospheric dust pollution, especially particulate matter below 2.5 μm, causes 3.3 million premature deaths per year worldwide. Although pollution sources are increasingly well known, the role of ecosystems in mitigating their impact is still poorly known. Our objective was to investigate the role of forests located in the surrounding of industrial and urban areas in reducing atmospheric dust pollution. This was tested using lichen transplants as biomonitors in a Mediterranean regional area with high levels of dry deposition. After a multivariate analysis, we have modeled the maximum pollution load expected for each site taking into consideration nearby pollutant sources. The difference between maximum expected pollution load and the observed values was explained by the deposition in nearby forests. Both the dust pollution and the ameliorating effect of forested areas were then mapped. The results showed that forest located nearby pollution sources plays an important role in reducing atmospheric dust pollution, highlighting their importance in the provision of the ecosystem service of air purification. [ABSTRACT FROM AUTHOR]

The results of antiproliferative activity against murine myeloma cells (line P3X63-Ag8.653) of water, ethanol, and methanol crude extracts of three lichen species belonging to the genusPeltigera(P. canina,P. elisabethae, andP. praetextata) are reported. Cell proliferation was evaluated by means of the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide test, which is commonly used to assess the activity of living cells through mitochondrial dehydrogenases. The results showed that water extracts were the most effective in reducing cell proliferation; however, 40 μl of allPeltigeraextracts, irrespective of water, ethanol, or methanol, induced a consistent reduction in cell proliferation. It is suggested that this important biological activity is due to antioxidant properties, possibly linked with phenolic compounds. A possible role of quaternary ammonium compounds is also discussed. [ABSTRACT FROM PUBLISHER]

This study investigated the relationship between nitrogen and carbon in the thalli of the lichen Evernia prunastri, with an emphasis on the role of the C/N balance in the response of this species to N excess. For this purpose, thalli collected at a remote site were sprayed for 5 weeks with NH4NO3 (0.05 and 1 M) and (NH4)2SO4 (0.025 and 0.5 M) solutions, and later analyzed for their C and N content. The results showed that the total N content of thalli increased and the total C content decreased along with increasing N concentration in the treatment solutions. Consequently, the C/N ratio also significantly decreased in treated samples. The Fv/Fm ratio, taken as a vitality index, turned out to be positively correlated with C content and negatively correlated with N content. It is suggested that N stress is caused by the lack of compensation for elevated ammonium levels with higher C assimilation. It is concluded that E. prunastri is a suitable bioindicator of N pollution and that the C/N ratio deserves further investigation as a promising tool for early warning of N excess. [ABSTRACT FROM AUTHOR]

To investigate the mechanisms of nitrogen (N) tolerance in lichens, we examined the physiological responses to increased N availability in different functional groups. Thalli of the nitrophytic Xanthoria parietina (L.) Th.Fr. previously grown both in an N-poor environment (~2kgNha[sup -1] year[sup -1]) and in an N-rich environment (~52 kg Nha[sup -1] year[sup -1]) were compared with the oligotrophic species Evernia prunastri (L.) Ach. and Usnea sp. Lichens were submitted to ammonium treatments. Maximum PSII efficiency, redistribution of the ions between the intra- and extracellular compartments and potassium and magnesium concentrations were the parameters used to check for the effects of N supply. The buffering capacity of the lichen extracts was also determined in untreated lichen thalli to check if different lichen behaviours were due to their ability to maintain the pH. The results showed a more similar response between X. parietina from the N-poor environment and the N-sensitive species than between X. parietina from the N-poor and N-rich environments, suggesting that X. parietina achieved N-tolerance after long-term exposure to N-rich environment. These results are important in understanding the effects of chronic ammonium pollution on one of the most sensitive components of the ecosystem, linking physiological response and ecological consequences. [ABSTRACT FROM AUTHOR]

The interpretation of lichen bioaccumulation data is of paramount importance in environmental forensics and decision-making processes. By implementing basic ideas underlying previous interpretative scales, new dimensionless, species-independent "bioaccumulation scales" for native and transplanted lichens are proposed. Methodologically consistent element concentration datasets were populated with data from biomonitoring studies relying on native and transplanted lichens. The scale for native lichens was built up by analyzing the distribution of ratios between element concentration data and species-specific background concentration references (B ratios), herein provided for Flavoparmelia caperata and Xanthoria parietina (foliose lichens). The scale for transplants was built up by analyzing the distribution of ratios between element concentration in exposed and unexposed samples (EU ratio) of Evernia prunastri and Pseudevernia furfuracea (fruticose lichens). Both scales consist of five percentile-based classes; namely, "Absence of", "Low", "Moderate", "High", and "Severe" bioaccumulation. A comparative analysis of extant interpretative tools showed that previous ones for native lichens suffered from the obsolescence of source data, whereas the previous expert-assessed scale for transplants failed in describing noticeable element concentration variations. The new scales, based on the concept that pollution can be quantified by dimensionless ratios between experimental and benchmark values, overcome most critical points affecting the previous scales. [ABSTRACT FROM AUTHOR]

Lichens are classified into different functional groups depending on their ecological and physiological response to a given environmental stressor. However, knowledge on lichen response to the synergistic effect of multiple environmental factors is extremely scarce, although vital to get a comprehensive understanding of the effects of global change. We exposed six lichen species belonging to different functional groups to the combined effects of two nitrogen (N) doses and direct sunlight involving both high temperatures and ultraviolet (UV) radiation for 58 days. Irrespective of their functional group, all species showed a homogenous response to N with cumulative, detrimental effects and an inability to recover following sunlight, UV exposure. Moreover, solar radiation made a tolerant species more prone to N pollution's effects. Our results draw attention to the combined effects of global change and other environmental drivers on canopy defoliation and tree death, with consequences for the protection of ecosystems.

Ammonia and ammonium have received less attention than other forms of air pollution, with limited progress in controlling emissions at UK, European and global scales. By contrast, these compounds have been of significant past interest to science and society, the recollection of which can inform future strategies. Sal ammoniac ( nūshādir , nao sha ) is found to have been extremely valuable in long-distance trade ( ca AD 600-1150) from Egypt and China, where 6-8 kg N could purchase a human life, while air pollution associated with nūshādir collection was attributed to this nitrogen form. Ammonia was one of the keys to alchemy-seen as an early experimental mesocosm to understand the world-and later became of interest as 'alkaline air' within the eighteenth century development of pneumatic chemistry. The same economic, chemical and environmental properties are found to make ammonia and ammonium of huge relevance today. Successful control of acidifying SO 2 and NO x emissions leaves atmospheric NH 3 in excess in many areas, contributing to particulate matter (PM 2.5 ) formation, while leading to a new significance of alkaline air, with adverse impacts on natural ecosystems. Investigations of epiphytic lichens and bog ecosystems show how the alkalinity effect of NH 3 may explain its having three to five times the adverse effect of ammonium and nitrate, respectively. It is concluded that future air pollution policy should no longer neglect ammonia. Progress is likely to be mobilized by emphasizing the lost economic value of global N emissions ($200 billion yr -1 ), as part of developing the circular economy for sustainable nitrogen management. This article is part of a discussion meeting issue 'Air quality, past present and future'.