https://hdl.handle.net/20.500.12327/5 Sat, 06 Jun 2026 16:21:20 GMT 2026-06-06T16:21:20Z https://hdl.handle.net/20.500.12327/5281 Nitzschia excavata sp. nov. (Bacillariaceae), a new diatom species from a post-mining reservoir revealed by morphology, molecular phylogeny, and metabarcoding-based biogeography Olszyński, Rafał M.; Mann, David; Zakrzewski, Piotr K.; Peszek, Łukasz; Ács, Éva; Shemesh, Sára; Trobajo, Rosa The Bogdałów post-mining reservoir (Poland) represents a slightly alkaline, moderately mineralised ecosystem formed by flooding a former lignite pit. Its anthropogenic origin and stable physicochemical conditions have enabled the development of species-rich diatom assemblages, particularly numerous Nitzschia (Bacillariaceae) species. To explore this diversity, an integrative approach combining microscopy and DNA-based analyses was employed. Morphological examinations were performed using light and scanning electron microscopy, as well as confocal laser scanning microscopy. Molecular phylogenetic analyses were based on the sequencing of the nuclear SSU rDNA and the chloroplast rbcL and psbC gene markers. This comprehensive study led to the discovery and formal description of Nitzschia excavata sp. nov., distinguishable by unique morphological features and a phylogenetically distinct lineage. Furthermore, environmental DNA metabarcoding and metagenomic database searches revealed sequences identical or closely related to the N. excavata sp. nov. lineage in freshwater habitats across Europe and China, indicating that this taxon has an unexpectedly broad distribution. These findings underscore the value of integrating classical morphological analysis with multi-marker molecular data in diatom taxonomy and demonstrate that anthropogenic habitats may support taxa with broader distributions than previously recognized. The study highlights the important role of metabarcoding and metagenomics in revealing cryptic diversity and clarifying the biogeographic patterns of newly described species. Thu, 28 May 2026 00:00:00 GMT https://hdl.handle.net/20.500.12327/5281 2026-05-28T00:00:00Z https://hdl.handle.net/20.500.12327/5280 Perspectives: Effect of global change drivers on carbon fluxes and resilience of European forests Gharun, Mana; Angove, Charlotte; Migliavacca, Mirco; Zhou, Yu; Buckeridge, Kate; Branquinho, Cristina; Collalti, Alessio; Nybakken, Line; Zhiyanski, Miglena; Sarginci, Murat; Koc, Ismail; Huseyin Donmez, Abdullah; López-Ballesteros, Ana; Godbold, Douglas; Machacova, Katerina; Guidi, Claudia; Koren, Gerbrand; Ostonen, Ivika; Sell, Marili; Pers-Kamczyc, Emilia; Kamczyc, Jacek; Aslan, Toprak; Preece, Catherine; Prikaziuk, Egor; Özkan, Ufuk; Vitali, Valentina; Havrdová, Alena; Grünzweig, José M.; Tomelleri, Enrico; Ullah, Sami; Stoeva, Lora; Nestola, Enrica; Vanguelova, Elena; Guerrieri, Rossella European forests play a central role for meeting the EU’s climate targets, but the declining carbon sink has left them trailing behind climate goals. Reversing this trend requires a systematic understanding of forest responses to shifting global change drivers, explicitly integrating aboveground and belowground processes. Here, we provide our perspective on the effects of multiple global change drivers on ecosystem-scale carbon fluxes (including both carbon dioxide (CO2) and methane (CH4)) and the resilience of these fluxes, based on direct flux observations (e.g., from eddy covariance towers). First, we present changes in several key drivers (warming, drought, atmospheric CO2, nitrogen deposition, winter warming, excess precipitation, late frost), over recent decades, some of which (winter warming, windthrow, excess precipitation, late frost) have received limited attention in forest carbon assessments. Some of these—such as winter warming—are expected to become increasingly frequent in the future. We then explicitly summarize how the four (more-frequently studied) key drivers affect carbon fluxes (i.e., CO2 and CH4 fluxes). The response of the net CO2 sink (i.e., net ecosystem productivity) is presented through its two component processes: gross primary productivity (GPP) and ecosystem respiration (Reco). When considered individually, global change drivers often produce relatively predictable responses in forest carbon fluxes: warming tends to enhance both GPP and Reco, elevated atmospheric CO₂ generally stimulates photosynthesis, and moderate nitrogen (N) inputs can enhance productivity in N-limited systems. However, when drivers interact, ecosystem responses frequently become non-linear, amplified, or even reversed relative to single-driver expectations. For example, warming alone may extend the growing season and increase GPP, but in combination with drought, elevated vapor pressure deficit suppresses stomatal conductance, reduces GPP, and can increase respiration losses during rewetting events. Similarly, the positive effect of rising CO₂ on productivity may be constrained by nutrient limitation or drought stress, while historical N deposition can temporarily sustain CO₂ fertilization effects but also increase vulnerability to climatic stressors. Under compound disturbances—such as drought followed by extreme precipitation or winter warming—ecosystem respiration pulses and structural damage can further reduce net ecosystem productivity (NEP). Collectively, these findings indicate that forest carbon dynamics cannot be reliably inferred from single-driver responses alone; instead, interacting drivers shape ecosystem resilience through feedbacks among physiological processes, soil biogeochemistry, and disturbance regimes, often leading to thresholds or tipping points in carbon sink strength. Mon, 25 May 2026 00:00:00 GMT https://hdl.handle.net/20.500.12327/5280 2026-05-25T00:00:00Z https://hdl.handle.net/20.500.12327/5279 Host-associated chemical cues mediating host-finding behaviour in the larval ectoparasitoid Cephalonomia tarsalis del Arco, Lidia; Fürstenau, Benjamin; Castañé, Cristina; Riudavets, Jordi BACKGROUND Understanding how parasitoids locate their hosts is essential for improving the effectiveness of these insects as biological control agents. The bethylid ectoparasitoid Cephalonomia tarsalis is a key natural enemy of the sawtoothed grain beetle Oryzaephilus surinamensis, an important stored product pest. While some aspects of its host-finding behaviour are understood, the significance of larval host-associated volatile cues remains largely unclear. This study investigated the influence of host-specific odours on host location by C. tarsalis females. RESULTS Volatile compounds released from fourth-instar larval faeces were identified by gas chromatography–mass spectrometry and their behavioural relevance was evaluated using Y-tube olfactometer bioassays alongside odours from different host stages (live larvae and adults) and from host-associated food substrates. Females responded positively to most of the tested odours, including those from host adults, larval faeces, and host-associated food substrates. Among the compounds identified in the faecal volatiles of host larvae, 1-pentadecene was found to be significantly attractive. In flight-cage experiments, 1-pentadecene induced behavioural responses in test parasitoids that were similar to those elicited by larval faeces. CONCLUSION Host-associated volatile cues, particularly those derived from larval faeces, play a key role in mediating the host-searching behaviour of C. tarsalis females. These findings provide a basis for the development of semiochemical-based approaches to enhance the efficiency of this biological control agent for stored-product pests. © 2026 The Author(s). Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry. Sun, 10 May 2026 00:00:00 GMT https://hdl.handle.net/20.500.12327/5279 2026-05-10T00:00:00Z https://hdl.handle.net/20.500.12327/5278 Species- and Level-Dependent Modulation of Growth and Skin and Intestinal Mucosal Microbiota in Rainbow Trout Fed Mushroom Stem Meals Reinoso, Samira; Saromines, Carl John; Torrecillas, Silvia; Tello Martín, Maria Luisa; Pérez Clavijo, Margarita; Gisbert, Enric Mucosal microbiomes play key roles in fish physiology by supporting digestion, nutrient absorption, metabolism, immune modulation, and pathogen defense. This study evaluated the effects of mushroom stem meals from Agaricus bisporus (AB) and Pleurotus ostreatus (PO) as nutritional alternatives to soybean meal (SBM) on growth performance and mucosa-associated microbiota in rainbow trout (Oncorhynchus mykiss). A 60-day feeding trial was conducted with juveniles (22.1 ± 0.3 g) at 16.02 ± 0.19°C using isoproteic (47%) and isolipidic (23%) diets containing 50 or 100 g kg−1 AB or PO meals (AB5, AB10, PO5, and PO10), plus a control (CTRL) diet without mushroom meals. Microbial communities in feed, anterior and posterior intestine (PI), and skin mucus (SK) were analyzed by 16S rRNA (V3–V4) sequencing, and functional pathways were inferred. Growth responses were mushroom meal type- and level-dependent. Fish fed the AB5 diet showed similar growth to the CTRL group (p > 0.05), while those fed AB10, PO5, and PO10 diets grew 8%, 25%, and 60% less, respectively (p ≤ 0.05). Feed intake (FI) was unaffected by AB meal but reduced by PO5 and PO10 diets (3% and 40%, respectively). AB diets maintained intestinal alpha diversity and community structure, whereas PO diets increased alpha diversity and altered beta diversity, favoring fermentative and opportunistic taxa while reducing beneficial fermenters. Mycoplasma abundance correlated positively with growth performance in both intestinal regions, while Bradyrhizobium abundance and Shannon diversity index correlated negatively in the anterior intestine (AI). Functional predictions showed enrichment of lipid and xenobiotic metabolism pathways in PO10-fed fish, while AB10 enhanced carbohydrate-related functions. SK microbiota diversity remained stable despite compositional shifts, with increases in fermentative taxa and reductions in potential pathogens. Overall, AB meal showed greater compatibility with rainbow trout growth performance, feed efficiency, and gut microbial homeostasis, whereas high PO inclusion impaired growth by reducing FI and inducing marked changes in the gut community structure. These findings suggest that AB meal at low inclusion levels may be used as an alternative to SBM without substantial effects on key performance indicators and gut microbiota in rainbow trout. Thu, 28 May 2026 00:00:00 GMT https://hdl.handle.net/20.500.12327/5278 2026-05-28T00:00:00Z