International University Institute

Abstract Urbanization represents one of the major anthropogenic alterations of the Earth's surface, with significant impacts on biodiversity and its functions. Soil animals are essential components of biodiversity, and their trophic interactions play integral roles in the functioning of terrestrial ecosystems. However, how urbanization reshapes soil food webs is largely unknown. We assessed the structure and function of soil food webs using stable isotope analysis and the energy flux approach in urban grasslands and woodlands in a subtropical city in China, using natural ecosystems in the city surroundings with the same vegetation type as the reference. In urban woodlands, total biomass was six times higher and energy flux was two times higher than in the reference natural forests, resulting in a 50% lower energy turnover (energy flux‐to‐biomass ratio) and supporting longer food chains. By contrast, urban grasslands had similar total biomass, total energy flux and energy turnover to wild grasslands, but both the bacterial‐to‐fungal ratio and soil consumption‐to‐faeces production ratio increased, suggesting accelerated soil carbon cycling. Further, we found that urbanization increases spatial variability of trophic interaction strengths, especially in woodlands, which was attributed to the strong specific predator–prey interactions and higher environmental heterogeneity of urban green spaces. Overall, contrary to the generally assumed negative impacts of land‐use changes on soil communities, our study demonstrates that urbanization enhances the total energy flux in soil food webs but changes the balance between different energy channels and increases the variability of trophic interactions. In addition, the divergent responses to urbanization observed in woodlands and grasslands emphasize the importance of vegetation‐specific management to improve soil ecosystem functioning, such as C sequestration in urban areas. Read the free Plain Language Summary for this article on the Journal blog.

Abstract The garden dormouse (Eliomys quercinus) inhabits a wide range of habitats, from urban areas in warm temperate lowlands to cool mountain ranges. Despite its adaptability, it has largely disappeared from its former range. While most forest populations in Germany are declining, some populations in cities remain stable. To better understand the ecology of this endangered species, VHF telemetry studies were conducted. Between May and September in 2021, 2022, and 2023, 19 adult individuals (7 males, 12 females) were tracked between 15 to 79 days. The animals were assigned to one of three habitat types: ‘Urban’ (entirely human-modified areas, n = 7), ‘Forest’ (forest habitat with minimal human presence, n = 6), and ‘Mixed’ (a combination of forest and human-modified areas, n = 6). Garden dormice had the largest home ranges (MCP100) in ‘Forest’ habitats (4.06 ha) followed by ‘Mixed’ (1.2 ha) and ‘Urban’ habitats (0.56 ha). They preferred structures with high coverage and proximity to food resources, such as structurally rich plant communities (‘Urban’), rock crevices and ruderal shrub vegetation, including berry bushes (‘Forest’). Nest sites offered protection from predators and a stable microclimate, and were predominantly located in buildings (‘Mixed’, ‘Urban’) and rock crevices (‘Forest’). They were changed frequently. Garden dormice occupied smaller home ranges in areas where human-provided resources were concentrated in a small space. Although garden dormice habitats and the resources they use differ in appearance, they fulfill the same ecological needs: sufficient food, safe movement through the habitat and secure nest sites.

Efficient immobilization of unspecific peroxygenases (UPOs) on hairy particles with homogeneous and Janus design possessing conductive core and polymeric shell was demonstrated. PDMAEMA brushes (hairs) with controlled chain lengths were successfully grown from the conductive silver particles allowing further immobilization of enzymes and keeping their activity. The Janus design of the synthesized particles maintained the conductivity of the core material. Enzyme immobilization on brush-modified particles was first carried out with two laccases as model enzymes [Trametes versicolor (TveLac) and Pycnoporus cinnabarinus (PciLac)] and then successfully extended to UPOs [two wild-type and one recombinant UPO from Marasmius rotula (MroUPO) and Agrocybe aegerita (AaeUPO, rAaeUPO)]. The most efficient immobilization was achieved for MroUPO on Janus particles. The enzyme loading is reversible and could be successfully repeated after cleaning of the particles. Thus, the successful immobilization of an MroUPO on conductive hairy Janus particles was demonstrated for the first time. The major advantage of the proposed approach lies in the reusability of the enzyme and its carrier, as well as in the use of conductive core materials, which could be promising, for example, as material for electrochemical biosensors in future.

Climate change is intensifying extreme climate events, fundamentally altering ecosystem disturbance regimes. Impacts on biodiversity are typically assessed using climate model outputs (i.e., temperature, precipitation) or by focusing on one type of extreme event. For this study, we used a new dataset covering four climate extremes (droughts, heatwaves, river floods, and wildfires) derived from the output of five climate models and six climate impact models for future projections under three climate scenarios (SSP1-2.6, SSP3-7.0 and SSP5-8.5) from the Inter-Sectoral Impact Model Intercomparison Project (ISIMIP Phase 3b). We assessed the exposure of 33,936 terrestrial vertebrate species (amphibians, birds, mammals, and reptiles). We also compiled published evidence on how species respond to extreme events. Heatwaves emerged as the most prevalent threat, with over 70% of species' geographic ranges projected to be exposed by 2050 (SSP3-7.0 scenario) - a 60% increase from 2000 levels. More than 21,000 species face heatwave exposure in 75% of their range. Wildfire exposure is projected to affect more than 20% of species ranges by 2050, increasing to 30% by 2085, with more than 5,000 species exposed in 50% of their range by mid-century. Notably, our findings indicate substantial multi-hazard exposure, with approximately 30% of species’ geographic ranges facing at least two types of extreme events by 2050. Hotspots are species-rich areas in the tropics. More than 70 species, mostly amphibians and reptiles, are projected to be exposed to a high frequency of three types of events over 75% of their range. Most of these species already have declining populations and are listed as threatened on the IUCN Red List of Threatened Species. Our study highlights the importance of studying the impacts of extreme events on biodiversity in a multi-hazard context. The combination of high exposure with documented negative impacts - such as heat stress mortality, reproductive failure, or wildfire injury – is of particular concern for already threatened species. This underscores the urgency of developing targeted interventions for vulnerable species.

Hyphae-forming fungi play a critical role in decomposing deadwood and plant litter, utilizing a variety of resources in forest ecosystems. While the redistribution of nitrogen and phosphorus by fungal hyphae between deadwood and soil has been established, the translocation of carbon (C) and its subsequent utilization remains unexplored. This study examines the fungal-mediated transfer of 13 C-cellulose from deadwood of European beech and Norway spruce to Norway spruce litter from an Oi/Oe horizon. We used a mesocosm double-chamber controlled system with a perforated intersection, including beech and spruce deadwoods (chamber I) and spruce litter (chamber II). After fungal hyphae growth in the intersection between the two chambers, mesocosms were incubated for 8–10 weeks at 20 °C in the dark. Following a pre-treatment phase, 13 C-cellulose was added to half of the deadwood chambers while the other half served as control without cellulose addition. The transfer of 13 C-cellulose from deadwood to spruce litter was assessed by measuring the abundance of 13 C in respiration and microbial biomass within the spruce litter. After incubation, the 13 C-cellulose recovered in spruce litter was higher for both respiration (7.75 ± 0.98 %) and microbial biomass (1.66 ± 1.01 %) for beech compared to the spruce deadwood (3.88 ± 1.07 % in respiration and 1.55 ± 1.37 % in microbial biomass). This indicates that, in both deadwood setups, more 13 C was recovered in respiration than in microbial biomass. Molecular analysis of the fungal hyphae at the intersection between the deadwood and spruce litter chambers identified Clitopilus baronii and Kuehneromyces mutabilis as the common and active deadwood-decaying fungi facilitating significant 13 C transfer (240–270 δ‰ in respiration, and 100–160 δ‰ in MBC), while the baseline without 13 C was −25 δ‰. This research provides new insights into the mechanisms of C transfer from deadwood to litter, suggesting an enhanced decomposition of litter by deadwood decaying fungi. • C transfer from deadwood increases respiration and microbial biomass in litter. • Fungal hyphae transferred more C from beech deadwood to spruce litter than spruce deadwood. • Clitopilus baronii and Kuehneromyces mutabilis deadwood fungi perform the C transfer.

ABSTRACTAs climatic extremity intensifies, a fundamental rethink is needed to promote the sustainable use of freshwater resources. Both floods and droughts, including water scarcity, are exacerbating declines in river biodiversity and ecosystem services, with consequences for both people and nature. Although this is a global challenge, densely populated regions such as Europe, East Asia and North‐America, as well as the regions most affected by climate change, are particularly vulnerable. To date mitigation measures have mainly focused on individual, local‐scale targets, often neglecting hydrological connectivity within catchments and interactions among hydrology, biodiversity, climate change and human wellbeing. A comprehensive approach is needed to improve water infiltration, retention and groundwater recharge, thereby mitigating the impacts of heavy rainfall and floods as well as droughts and water scarcity. We propose a holistic catchment‐scale framework that combines mitigation measures including conventional civil engineering methods, nature‐based solutions and biodiversity conservation actions. This framework integrates legislation, substantial funding and a governance structure that transcends administrative and discipline boundaries, enabling coordinated actions across multiple spatial and temporal scales. It necessitates the collaboration of local and regional stakeholders including citizens, scientists and practitioners. A holistic vision for the sustainable management of freshwater resources could have synergistic effects that support biodiversity and mitigate climate change within functional ecosystems that deliver benefits to people.

Investigation of the secondary metabolites of the solid-state rice cultures from the European basidiomycetes Terana coerulea and Sparassis brevipes afforded three previously undescribed secondary metabolites identified as two p-terphenyl derivatives (1 and 2) and one orsellinic acid congener (3) in addition to another known, isoeverninic acid (4). Chemical structures of the isolated compounds were elucidated through comprehensive 1D and 2D NMR spectroscopic analyses, coupled with HR-MS and other spectral methods. The isolated compounds were assessed for their cytotoxic and antimicrobial activities. Compound 1 revealed weak antimicrobial properties, whereas the inseparable mixture of 3 and 4 featured moderate cytotoxic and antimicrobial effects.

Abstract As camera trapping grows in popularity and application, some analytical limitations persist including processing time and accuracy of data annotation. Typically images are recorded by camera traps although videos are becoming increasingly collected even though they require much more time for annotation. To overcome limitations with image annotation, camera trap studies are increasingly linked to community science (CS) platforms. Here, we extend previous work on CS image annotations to camera trap videos from a challenging environment; a dense tropical forest with low visibility and high occlusion due to thick canopy cover and bushy undergrowth at the camera level. Using the CS platform Chimp&See, established for classification of 599 956 video clips from tropical Africa, we assess annotation precision and accuracy by comparing classification of 13 531 1‐min video clips by a professional ecologist (PE) with output from 1744 registered, as well as unregistered, Chimp&See community scientists. We considered 29 classification categories, including 17 species and 12 higher‐level categories, in which phenotypically similar species were grouped. Overall, annotation precision was 95.4%, which increased to 98.2% when aggregating similar species groups together. Our findings demonstrate the competence of community scientists working with camera trap videos from even challenging environments and hold great promise for future studies on animal behaviour, species interaction dynamics and population monitoring.

Lignocellulose is a major component of vascular plant biomass. Its decomposition is crucial for the terrestrial carbon cycle. Microorganisms are considered primary decomposers, but evidence increases that some invertebrates may also decompose lignocellulose. We investigated the taxonomic distribution and evolutionary origins of GH45 hydrolases, important enzymes for the decomposition of cellulose and hemicellulose, in a collection of soil invertebrate genomes. We found that these genes are common in springtails and oribatid mites. Phylogenetic analysis revealed that cellulase genes were acquired early in the evolutionary history of these groups. Domain architectures and predicted 3D enzyme structures indicate that these cellulases are functional. Patterns of presence and absence of these genes across different lineages prompt further investigation into their evolutionary and ecological benefits. The ubiquity of cellulase genes suggests that soil invertebrates may play a role in lignocellulose decomposition, independently or in synergy with microorganisms. Understanding the ecological and evolutionary implications might be crucial for understanding soil food webs and the carbon cycle.