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Shedding light on overlooked pollinators: Global insights into floral interactions of velvet ants (Hymenoptera: Mutillidae and Myrmosidae)
Get PDFPlant-animal interactions constitute a recurrent and central focus in ecological research, with pollination representing one of its most extensively studied aspects. While certain insect orders have traditionally received considerable attention due to their abundance as flower visitors and their efficiency in pollination, it is undeniable that the significance of other less popular and neglected flower visitors cannot be overlooked. In this regard, velvet ants (Hymenoptera: Mutillidae and Myrmosidae) constitute an excellent study model, as the knowledge of their ecology (e.g., their feeding preferences) is still very limited despite being reported as common flower visitors. In this study, we conducted a comprehensive global review of velvet ant floral visitation patterns using citizen science data, literature records and unpublished data. We used network metrics to explore their flower-visit preferences on a global scale, as well as depending on the bioregion where the interaction was recorded and the sex of the velvet ants. In addition, we explored their potential role as pollen vectors examining the number of photographic records where velvet ants had pollen attached to their bodies. Our analyses revealed that velvet ants are generalist flower visitors of a wide range of plant families, with Apiaceae, Asteraceae, Euphorbiaceae, Rhamnaceae and Fabaceae as the most visited. Despite differences in flowering plant and velvet ant composition across bioregions causing differences in plant-velvet ant interactions, velvet ants visited flowering plants in a generalistic way across the globe. Males and females seemed to visit different plant communities, with males being more generalist than females. Furthermore, 42.7% (likely an underestimation) of the photographic records of velvet ants visiting flowers showed pollen attached to their bodies in the same way as in other pollinating insects, suggesting the same potential role as pollinators. There remains ample scope for ongoing investigation to comprehensively assess the importance of numerous arthropods, including velvet ants, not only as flower visitors but also as potential pollinators
Leaf Turgor Loss Does Not Coincide With Cell Plasmolysis in Drought-Tolerant Chaparral Species
Get PDFThe water potential at which leaf cells lose turgor (Psi(TLP)) is a useful predictor of whole-plant drought tolerance and biome wetness. However, many plants can achieve water potential values below Psi(TLP) and recover, raising questions about the physiological processes that occur below Psi(TLP). We established a controlled greenhouse experiment to induce turgor loss on six shrub species from a Mediterranean-type ecosystem in Southern California and characterised physiological and leaf-structural adjustments to Psi(TLP). We documented seasonal adjustments in Psi(TLP), both with and without applied drought. Stomatal closure always occurred below Psi(TLP), and the margin between the two phenomena increased with lower Psi(TLP). Drought tolerance was strongly correlated with heat tolerance. Most histological responses to Psi(TLP) involved shrinkage of both spongy mesophyll cells and intercellular air spaces, leading to reduced leaf thickness, but not plasmolysis. Overall, our results indicate a propensity to reach Psi values far below Psi(TLP) and maintain function for extended periods of time in Southern California shrubs. Whereas species in many ecosystems fall below Psi(TLP) for brief periods of time, the erratic nature of precipitation patterns makes Southern California an outlier in the range of operational plant water potentials
Fertilizer-induced soil carbon rapidly disappears after clearcutting in boreal production forests
Get PDFForests have a substantial potential to contribute to climate change mitigation, depending on how they are managed. Forest fertilization with nitrogen is used to increase tree productivity in Fennoscandian forests, but it can also increase soil carbon stocks. However, such forests are often harvested through clearcutting, a practice known to impact soil carbon stocks, nitrogen mineralization and biodiversity. To test whether fertilizer-induced soil carbon stocks are persistent, we studied post-clearcut soil carbon and nitrogen stocks, soil respiration, tree growth, ground vegetation and soil fungal communities in 48 previously fertilized and unfertilized production forests in central Sweden. In the first year after clearcutting, clearcuts of previously fertilized forests stored 7 t (+30%) more carbon and 210 kg (+32%) more nitrogen per hectare in the soil organic layer than clearcuts of unfertilized forests. Four to 13 years after clearcutting, there was no significant difference in carbon and nitrogen stocks of the organic layer, or in soil CO2 efflux, between clearcuts of previously fertilized and unfertilized forests. Saprotrophic ascomycetes were more abundant in clearcuts of previously fertilized forests, independent of time since clearcutting. Previous fertilization did neither result in increased growth of regenerating trees nor alter understory vegetation. Synthesis and applications. Overall, the carry-over effects on biodiversity from forest fertilization into stands regenerating after clearcutting were limited. We conclude that soil organic carbon stores induced by fertilization are short-lived and do not persist after clearcutting. Consequently, the potential of forest fertilization to mitigate climate change is likely limited to increases in aboveground biomass and the products that can be produced with the harvested biomass. Our study raises questions about where the added nitrogen and the fertilizer-induced increase in soil carbon have ended up-knowledge that is essential for making well-informed decisions about future fertilization strategies.& Ouml;kad kolinlagring i skog har potential att bidra till att begr & auml;nsa klimatf & ouml;r & auml;ndringar, men omfattningen beror p & aring; hur skogen brukas. I Fennoskandien anv & auml;nds kv & auml;veg & ouml;dsling som en metod f & ouml;r att & ouml;ka skogsproduktionen. F & ouml;rutom att fr & auml;mja tr & auml;dens tillv & auml;xt kan g & ouml;dsling & auml;ven bidra till att & ouml;ka markens kollager. Den vanligaste avverkningsmetoden i Fennoskandien & auml;r kalavverkning, vilket p & aring;verkar markens kollager, kv & auml;vemineralisering och biologisk m & aring;ngfald. F & ouml;r att unders & ouml;ka de l & aring;ngsiktiga effekterna av g & ouml;dsling p & aring; kollagring studerade vi hur markens kol- och kv & auml;velager, markrespiration, tr & auml;dtillv & auml;xt samt sammans & auml;ttningen av markvegetation och svampsamh & auml;llen skilde sig efter kalavverkning mellan 24 tidigare g & ouml;dslade och 24 og & ouml;dslade produktionsskogar i centrala Sverige. Under det f & ouml;rsta & aring;ret efter avverkning inneh & ouml;ll det organiska markskiktet p & aring; hyggen fr & aring;n tidigare g & ouml;dslade skogar i genomsnitt 7 ton mer kol (+30 %) och 210 kg mer kv & auml;ve (+32 %) per hektar j & auml;mf & ouml;rt med hyggen fr & aring;n og & ouml;dslade skogar. Fyra till tretton & aring;r efter avverkning fanns det inga signifikanta skillnader i kol- och kv & auml;velager i det organiska markskiktet eller i markens CO2-avg & aring;ng mellan hyggen fr & aring;n tidigare g & ouml;dslade och og & ouml;dslade skogar. Oberoende av tid sedan avverkning var Saprotrofa spors & auml;ckssvampar mer vanligt f & ouml;rekommande p & aring; hyggen fr & aring;n tidigare g & ouml;dslade skogar. Tidigare g & ouml;dsling gav inte upphov till & ouml;kad tr & auml;dtillv & auml;xt eller f & ouml;r & auml;ndrad markvegetation i n & auml;stkommande skogsgeneration. Syntes och till & auml;mpningar. De l & aring;ngsiktiga effekterna av skogsg & ouml;dsling p & aring; biologisk m & aring;ngfald in i n & auml;sta skogsgeneration & auml;r begr & auml;nsade. P & aring; samma s & auml;tt leder g & ouml;dsling inte till en varaktig & ouml;kning av kolf & ouml;rr & aring;det i det organiska markskiktet. Vi drar d & auml;rf & ouml;r slutsatsen att potentialen f & ouml;r att l & aring;ngsiktigt & ouml;ka skogens kolf & ouml;rr & aring;d-och d & auml;rmed motverka klimatf & ouml;r & auml;ndringar-genom konventionell skogsg & ouml;dsling sannolikt & auml;r begr & auml;nsad till en & ouml;kning av kolf & ouml;rr & aring;det i ovanjordisk biomassa fram till avverkning samt i de produkter som framst & auml;lls fr & aring;n den avverkade biomassan. V & aring;r studie v & auml;cker fr & aring;gor om vart det tillsatta kv & auml;vet och den g & ouml;dselinducerade & ouml;kningen av markkolet tagit v & auml;gen - kunskap som beh & ouml;vs f & ouml;r att fatta v & auml;lgrundade beslut om framtida g & ouml;dslingsstrategier
Detection of drainage ditches from LiDAR DTM using U-Net and transfer learning
Get PDFAccurate mapping of ditches is essential for effective hydrological modeling and land management. Traditional methods, such as manual digitization or threshold-based extraction, utilize LiDAR-derived digital terrain model (DTM) data but are labor-intensive and impractical to apply for large-scale applications. Deep learning offers a promising alternative but requires extensive labeled data, often unavailable. To address this, we developed a transfer learning approach using a U-Net model pre-trained on a large high-quality Swedish dataset and fine-tuned on a smaller localized Estonian dataset. The model uses a single-band LiDAR DTM raster as input, minimizing preprocessing. We identified the optimal model configuration by systematically testing kernel sizes and data augmentation. The best fine-tuned model achieved an overall F1 score of 0.766, demonstrating its effectiveness in detecting drainage ditches in training data-scarce regions. Performance varied by land use, with higher accuracy in peatlands (F1 = 0.822) than in forests (F1 = 0.752) and arable land (F1 = 0.779). These findings underscore the model's suitability for large-scale ditch mapping and its adaptability to different landscapes
Contrasting responses of Arctic charr and brown trout to compensatory nutrient enrichment in an oligotrophicated reservoir
Get PDFMany large lakes in northern Scandinavia have become oligotrophicated due to hydroelectric water regulation in the twentieth century, causing a loss of littoral habitat and negative consequences for ecosystem productivity, fish populations, and fisheries. Compensatory nutrient enrichment is a potential remediation method that has successfully been carried out in Canada and the US. Here we assessed the response of Arctic charr (Salvelinus alpinus) and brown trout (Salmo trutta) to nutrient addition in a whole lake experiment in Stor-Mj & ouml;lkvattnet, Sweden, with nearby Burvattnet as a reference. Nitrate and phosphate were added for eight consecutive years. The study also included sampling the seventh year after discontinuation of nutrient addition, which allowed us to investigate how long nutrient enrichment would be effective on fish growth. Populations of Arctic charr and brown trout responded quickly and vigorously to the treatment, with approximately a doubling of the catch per unit effort. Nutrient addition had a consistent positive effect on charr length, weight, and condition at a given age, with a median response to nutrient addition (as measured by Shapley values) of 32 mm, 45 g, and 0.087 g cm-3 x 100. The response in length and weight was strongest in the age classes 4+ and 5+. The corresponding responses of trout were 13 mm, 32 g, and 0.044 g cm-3 x 100, respectively. Seven years after the enrichment had ended, charr at ages = 7+), however, were in good condition, suggesting that those fish, as young had experienced the excellent conditions prevailing in the last years of nutrient enrichment and largely kept this advantage. We conclude that compensatory nutrient addition is a useful method for restoring charr populations and reversible
Microaceticoccus formicicus gen. nov., sp. nov., an ammonia-tolerant formate-utilizing bacterium originating from a biogas process
Get PDFA strictly anaerobic bacterial strain, designated as AMB_02T, was isolated from a propionate enrichment culture obtained from a high-ammonia biogas digester. The cells were anaerobic and coccoid (0.5 mu m), often appearing as diplococci or in a short chain of three to four cells. Growth was observed between 20 and 45 degrees C (optimum at 37-39 degrees C), with an initial pH of 6.5-9.0 (optimum pH 8.0-8.5), and the species tolerated up to 0.8 M NH4Cl and 0.5 M NaCl. The major cellular fatty acids were C16 :0 (31.6%), C14 :0 (14.6%) and C18:0 (13.3%). AMB_02T grew with formate, carbohydrates and AA, including asparagine, histidine, tryptone and tryptophan. Acetate was the major product formed. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain AMB_02T was most closely related to the species Citroniella saccharovorans (92.5%). The genome of strain AMB_02T was 2.5 Mb in length with a G+C content of 34.8 mol%, and 2,354 protein-coding genes were predicted. Furthermore, genes coding for the reductive glycine pathway potentially used for formate metabolism were identified. Comparative genomic analysis of AMB_02T revealed the closest similarity to C. saccharovorans [21.2% digital DNA-DNA hybridization (dDDH) and 77.4% average NT identity (ANI)] and to Parvimonas micra (24.4% dDDH and 76.9% ANI). Based on the phenotypic characteristics and phylogenetic analyses, AMB_02T is regarded as a novel genus, Microaceticoccus, within the family Peptoniphilaceae for which the species name Microaceticoccus formicicus is proposed. The type strain is AMB_02T=DSM 110248T=JCM 39108T
Olfactory responses of the variegated fruit fly, Phortica variegata, an emerging vector of the zoonotic eyeworm Thelazia callipaeda, to ecologically relevant volatiles
Get PDFBackgroundThe variegated fruit fly, Phortica variegata (Drosophilidae: Steganinae), is native to Europe and has emerged as a major vector of ocular nematosis caused by Thelazia callipaeda (Rhabditida: Thelaziidae), following the its introduction into Europe from Asia. Male P. variegata transmit these nematodes by feeding on tears of mammals, including wild and domestic carnivores (foxes, beech martens, wild cats, and dogs), lagomorphs, and humans. Understanding the olfactory responses of P. variegata to volatile cues is essential for developing attractant-based surveillance and control strategies, yet its olfactory ecology remains largely unexplored.MethodsWe used gas chromatography coupled electroantennography to measure antennal responses to synthetic and natural volatile blends. A comparative analysis was performed on the antennal responses of both sexes of P. variegata and its well-studied relative, Drosophila melanogaster. Components of the synthetic blends were selected based on the odorant receptor repertoire of D. melanogaster and established mosquito attractants, with the rationale that conserved olfactory receptors among dipterans may allow P. variegata to detect similar compounds. Volatile extracts collected using active carbon adsorbent traps were also tested on the antennae and analyzed using gas chromatography coupled mass spectrometry.ResultsMale P. variegata showed higher antennal responses to phenol, 3-octanone, and sulcatone than females, indicating olfactory sexual dimorphism. Compared to D. melanogaster, the antennae of P. variegata did not respond to several common plant alcohols and terpenoids. Instead, they showed stronger responses to compounds such as anisole, ethyl propanoate, butyl propanoate, propyl acetate, 3-octanone, nonanal, and decanal, suggesting that peripheral olfaction in P. variegata may be more tuned to microbial volatiles.ConclusionsPhortica variegata exhibits sexual dimorphism in olfactory responsivity, with males showing greater responsiveness to volatiles associated with host-seeking in other zoophilic dipterans, potentially guiding them to mammalian hosts for tear-feeding. Compared to D. melanogaster, P. variegata is more responsive to microbial and yeast-related volatiles and less responsive to plant-derived terpenoids, suggesting a foraging ecology linked to microbial substrates. The antennally detected volatiles identified in this study can be used as candidates for further behavioral studies to develop lures for vector management
Development of edible spoons using non-traditional flours
Get PDFThis work aimed to develop edible spoons from non-traditional types of flour that could help reduce pollution related to the use of plastic cutlery. Moreover, the experimentally produced edible spoons were fortified with health-enhancing bioactive compounds from non-traditional flours. Edible spoons were made by blending different types of flours, including acorn, pumpkin seeds, poppy seeds, and wheat, with the addition of water to form a homogenous, formable dough. The spoons were baked at 180 degrees C for 10 min and subjected to a dryer to achieve an even firmer texture. Next, the following parameters were determined: total polyphenol content, composition of phenolic compounds, antioxidant activity, and the textural profile. The highest total polyphenol content was recorded in acorn flour samples, with a value of 14.0 mg GAE/g in the sample containing 30 % acorn flour. This sample also showed the highest antioxidant activity with a value of 127.3 mu mol TE/g and the highest concentrations of rutin, myricetin, catechin, and naringenin. The highest hardness was recorded in the sample with the addition of 10 % acorn flour. Our study highlighted a simple and effective method of producing edible and biodegradable spoons, offering a sustainable alternative to single-use plastic cutlery
Assessment of vulnerability and resilience of smallholder farming households to flood risks: Insights from the Southern Punjab region of Pakistan
Get PDFThe frequency and severity of flood hazards in Pakistan have remarkedly increased in recent decades, posing significant socio-economic and environmental challenges to affected areas, particularly among smallholder farming communities. The present study employs an updated vulnerability assessment framework based on the IPCC AR6 (sixth assessment report, 2023) guidelines, distinguishing exposure from vulnerability. It also develops and operationalizes multidimensional resilience indices to assess the resilience of 269 smallholder farming households across three flood-affected districts in Southern Punjab, Pakistan. This study advances beyond previous research by utilizing latent class analysis (LCA) approach to cluster surveyed households based on their resilience index scores and examine the impact of selected sociodemographic characteristics on their cluster membership. The results reveal high vulnerability and notable geographical disparities in flood vulnerability across the three districts. The findings show that resilience index scores are generally low and more or less homogenous across the studied districts, with some variations pertaining to specific components. Based on LCA analysis, the findings reveal that nearly half of the surveyed households exhibit low resilience, while the remaining households are classified as moderately or highly resilient. Regarding the role of demographic and socio-economic characteristics in shaping the resilience of farming households, income, education, and age stand out as primary determinants of resilience. The study highlights the need for effective interventions and an integrated approach to flood risk management that considers different components of vulnerability and resilience while being responsive to farming households' evolving needs and preparedness in face of intensifying climate change impacts