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Soil structural indicators as predictors of biological activity under various soil management practices
Full text linkSoil structure is a key feature in controlling the turnover of organic matter in soils. The spatial arrangement of solids and pores in agricultural topsoil can be actively influenced by management practices, such as tillage and cropping systems, which in turn can affect the resident microbial communities and their activities. However, carbon mineralisation and microbial activity are usually measured in sieved samples, which provides information on gross potentials under optimal conditions. Under these conditions, the spatial heterogeneities that are specific to different management practices are reduced or totally removed. In this study, we combined X-ray computer tomography (X-ray CT) and isothermal calorimetry to investigate the effect of soil structure on heat dissipation, as an indicator of biological activity. Samples were collected from the topsoil of a long-term field experiment (12 years) that included four different land uses: conventional vs. reduced tillage, each with either maize or winter wheat as the main crop in the rotation. We compared the response of undisturbed soil cores (3 cm in height, 2.7 cm in diameter) to the addition of water and glucose in specific pore sizes, ranging in radii of 15 to 75 mu m or 3 to 75 mu m. The pore structure and indicators of particulate organic material were quantified using Xray CT with a voxel resolution of 15 mu m. This allowed us to distinguish between the effects of crop rotation and tillage regime on biological activity, soil structure and the feedback between the two. Heat dissipation correlated significantly with X-ray CT derived porosity, pore surface density and soil matrix grey value, all of which were affected by both tillage regime and crop rotation. Heat dissipation in maize plots after glucose addition to the pore size range with radii of 3 to 75 mu m was greater than in the winter wheat systems, but not when added to the pore size range with radii of 15 to 75 mu m. The study showed that structural indicators can explain up to 81 % and 95 % of the variance in total heat dissipation after glucose and water addition, respectively, but only 60 % of the heat dynamics, here defined as the time taken for 50 % of total heat to be dissipated. The results emphasise the importance of soil structure in regulating microbial decomposition of soil organic matter and warrants further investigations
Bridging environmental stress and internal physiology to mosquito biology
Full text linkMosquitoes rely on diverse internal and external cues to regulate key physiological processes and behaviour. Climate change alters the distribution and behaviour of mosquitoes, including Aedes aegypti, a primary vector of dengue and yellow fever. However, how vectoring females respond to climate change drivers, such as elevation in CO2, and abiotic stressors, including desiccation, remains unclear. This study shows that exposure to elevated CO2 levels combined with extended egg desiccation periods differentially alters larval development and survival, with carry-over effects on adult life-history traits and feeding behaviour (Paper I). Female mosquitoes use their peripheral olfactory system to locate nectar and blood resources. Transcriptomic and functional ontology analyses of olfactory tissues, the antennae and maxillary palp, reveal significant changes in gene expression related to stress and chemosensation, particularly in the CO2-sensing maxillary palp, in response to elevated CO2 and extended egg quiescence (Paper II). Collectively, these findings show that climate change can impact mosquito population dynamics and adult foraging behaviours. Teneral females are attracted to floral sources to replenish their energy reserves, while ageing induces a gradual shift to host-seeking, correlated with a concerted increase in chemosensory receptor expression, with exceptions, such as odorant receptor, Or117 which follows an inverse expression pattern. The mechanism underlying Or117 gene expression and age-dependent floral-seeking was investigated through behavioural assays, electrophysiology, receptor characterisation and functional genomics. Females display an age- and mating-state-dependent floral seeking behaviour, in which Or117 and its ligand, camphor are required for the attraction in teneral unmated females (Paper III). As a whole, the findings broaden our understanding of mosquito adaptation to internal cues and environmental stressors, with implications for vector ecology and disease transmission
Assessment of Soil Science in European Higher Education to Meet Growing Soil Awareness Needs
Full text linkHumanity is facing a number of global challenges coupling soils and essential ecosystems, biodiversity, food production, and climate change. Hence, knowledge and expertise in soil science and soil management are increasingly needed to address these issues for sustainability and development. Soil science in higher education (HE) will be one essential vehicle to provide a new generation with skills and expertise. The aim of this study was to assess the current state of soil science in European higher education by assessing the existing degrees offered, teaching and learning approaches (TLAs) used, and exploring collaborations in internationalisation among higher education institutions (HEIs) in Europe. A survey was conducted in 2020-2021 and 94 responses were received from HEIs teaching soil science in 25 European countries. Results showed that only 16% of HEIs hosted a dedicated soil science department. In most cases, soil science was embedded in departments with other academic topics, mainly environmental sciences and agronomy. Full degree programs in soil science were offered in 28% (BSc), 37% (MSc) and 37% (PhD) of the HEIs (N = 75). Regarding internationalisation of HEIs, only 6% responded that they had international joint programs in place at all levels of education. Twenty-five HEIs (37%) expressed aspirations to establish international programs while 24 (35%) saw no need for joint programs. The top three priorities among the HEIs were to attract students from abroad, develop strategic research partnerships, and provide more opportunities to send students abroad. Traditional lectures dominated TLAs in most soil science courses, especially at BSc level, where 40% of the HEIs responded that more than half of a soil course is delivered as lectures. Several respondents claimed curricula had not changed significantly in the last 5 years. Computer/modelling was either not included or included as a small share in teaching according to 96% (BSc) and 98% (MSc) of the HEIs. We conclude based on the sample, soil science at European HEIs appears conservative, but with scope to strengthen to deliver better soil science expertise for the future. More diverse TLAs and updated teaching materials are needed to provide the next generation of experts with the skills needed to address local and global sustainability challenges related to soils
Official and private animal welfare inspectors' perception of their own on-site inspections
Full text linkThe presence of a trustworthy and effective animal welfare control system is important both for animal welfare and for public and consumer trust. The inspectors' main task, regardless of whether they are official inspectors or private auditors, is to check for and enforce compliance with any relevant regulations. The aim of this study was to investigate how official animal welfare inspectors and private animal welfare auditors in Sweden perceive their inspection work and to explore any differences in the perception of being an inspector between these two groups. An electronic questionnaire was developed and received responses from 108 official inspectors and 22 private auditors (mainly inspecting the KRAV standard, Arlag & aring;rden (R), and the Trotter Health Standard). The results show that the official inspectors and private auditors usually enjoy their work, and they quite often have similar ambitions and views on what characterizes a good inspector. The respondents stated, for example, that it is important to have good dialog with the inspected animal keeper, that it is important to make uniform assessments (even if this can be challenging to achieve), and that animal keepers quite often show their appreciation after an inspection. However, there were also a number of differences in perception between the groups. For example, the official inspectors felt more exposed to unpleasant and threatening situations, while the private auditors were more likely to report the keeper being expected as acting nicely, professionally and relaxed during routine inspections. The official inspectors had a slightly more negative attitude toward the presence of private auditors than the other way around. Nevertheless, the respondents were in agreement that their collaboration and communication needed to be improved. One should bear in mind that the official inspectors also carry out inspections after complaints and more often make unannounced inspections. They not only inspect farms and horse premises, as the private auditors do, they also inspect different pet premises and have a secondary position of power as representatives of the government compared to the private auditors. These various circumstances may partly explain different views and perceptions between the official inspectors and the private auditors
Valuing structured alternatives for retrofitting blue-green infrastructure at a catchment scale using the Benefit Estimation Tool (B£ST)
Full text linkBlue-green infrastructure (BGI) options are considered to be more sustainable practices for water management and bring a range of benefits over and above water management. Davidshall in Malm & ouml;, Sweden, has been used as a case area to assess the multiple benefits of implementing BGI, considering seven alternative BGI schemes systematically developed along two scales: naturalness (i.e. more/less engineered/complex) and spatial distribution (e.g. decentral vs. end-of-pipe). The baseline alternative was the existing situation. The Benefit Estimation Tool (B ST) pound was used to carry out a socio-economic assessment. The overall benefits varied significantly (two orders of magnitude), depending on the BGI scheme implemented: the greatest values were associated with natural decentral, natural decentral/end-of-pipe, and engineered decentral/end-of-pipe alternatives, those including sub-surface and open dry detention, stormwater tree pits, and rain gardens. The three B ST pound categories providing the greatest benefits were enhancing amenity, benefiting health, and reducing flooding. Cultural ecosystem services were provided by all alternatives, and two alternatives (natural decentral and natural decentral/end-of-pipe) also provided regulating ecosystem services. The study showed that amenity and health were the most significant benefits of BGI implementation, contrasting with the main aim of BGI implementation, which was stormwater management (water quality and flood protection)
Importation of the exotic tick Amblyomma geoemydae into Sweden via illegally introduced turtles (Geoemyda spengleri) from Thailand
Full text linkIllegal importation of animals as pets might be followed by the introduction of exotic tick species, potential vectors of pathogens that can have an impact on wildlife and/or domestic animals and on humans. Therefore, permanent measures of surveillance and control on imported reptiles are emphasized. In February 2024, black-breasted leaf turtles (Geoemyda spengleri) (n = 31) were illegally imported into Sweden from Thailand. The turtles were sent by the Swedish Customs Criminal Department West in Gothenburg to a public aquarium and terrarium (Tropicarium, Kolm & aring;rden, Ostergotland county) to be kept in quarantine. At the Tropicarium the turtles were found to be infested by ticks. All ticks (n = 3) found were removed and stored in ethanol. The finding (including photos of the ticks) was reported to the Swedish Veterinary Agency (SVA, Uppsala) using the Report Tick Tool, a surveillance system developed by the SVA itself. The three collected ticks were identified based on morphology and genetics as Amblyomma geoemydae nymphs. This discovery demonstrates that SVA's surveillance tool can function as an early warning system for newly introduced tick species and to promptly identify exotic tick species which can carry viruses, bacteria, and/or parasites that are not currently present in the country
Turbidity reduces territory defence and exploration in an East African cichlid, Neolamprologus pulcher
Full text linkHuman activities increase turbidity in aquatic environments worldwide, which often affects fish behaviour. However, predicting how species react to higher turbidity remains difficult, as responses vary depending on the species, their ecology and the ecosystem. It is thus important to improve our understanding of the responses of fishes living in ecosystems experiencing recent increases in turbidity, especially those with unique species compositions where biodiversity is most vulnerable. One such ecosystem is Lake Tanganyika in East Africa, which is home to a diverse fish community with a high degree of endemism. In this study, we conducted a laboratory experiment with the territorial cichlid, Neolamprologus pulcher, which is endemic to Lake Tanganyika, to investigate the effects of increased turbidity on territorial and exploratory behaviour. We found that moderate increases in turbidity led to reduced territory defence, decreased exploration and increased time spent in shelters. Given that these fish live in large colonies, feed on planktonic particles in the water column and defend their territory against conspecific and heterospecific intruders, these behavioural changes are likely to have substantial implications for their social structure and reproduction in their native environments. Our study raises important questions about whether these effects will persist in the long term as human activities are likely to continue to increase turbidity in the lake over the coming decades and whether the responses to turbidity affect the community composition of fishes in Lake Tanganyika. (c) 2025 The Authors. Published by Elsevier Ltd on behalf of The Association for the Study of Animal Behaviour. This is an open access article under the CC BY license (http://creativecommons.org/licenses/ by/4.0/)
A major trade-off between growth and defense in Arabidopsis thaliana can vanish in field conditions
Full text linkWhen wild plants defend themselves from pathogens, this often comes with a trade-off: the same genes that protect a plant from disease can also reduce its growth and fecundity in the absence of pathogens. One protein implicated in a major growth-defense trade-off is ACCELERATED CELL DEATH 6 (ACD6), an ion channel that modulates salicylic acid (SA) synthesis to potentiate a wide range of defenses. Wild Arabidopsis thaliana populations maintain significant functional variation at the ACD6 locus, with some alleles making the protein hyperactive. In the greenhouse, plants with hyperactive ACD6 alleles are resistant to diverse pathogens, yet they are of smaller stature, their leaves senesce earlier, and they set fewer seeds compared to plants with the standard allele. We hypothesized that ACD6 hyperactivity would not only affect the growth of microbial pathogens but also more generally change leaf microbiome assembly. To test this in an ecologically meaningful context, we compared plants with hyperactive, standard, and defective ACD6 alleles in the same field-collected soil, both outdoors and in naturally lit and climate-controlled indoor conditions, taking advantage of near-isogenic lines as well as a natural accession and a CRISPR-edited derivative. We surveyed visual phenotypes, gene expression, hormone levels, seed production, and the microbiome in each environment. The genetic precision of CRISPR-edited plants allowed us to conclude that ACD6 genotype had no effect on mature field plants in our setting, despite reproducibly dramatic effects on greenhouse plants. We conclude that additional abiotic and/or microbial signals present outdoors-but not in the greenhouse-greatly modulate ACD6 activity. This raises the possibility that the fitness costs of other commonly studied immune system genes may be grossly misjudged without field studies
Genome editing for sustainable agriculture in Peru: advances, potential applications and regulation
Full text linkPeruvian agriculture is characterize by crops such as potato, maize, rice, asparagus, mango, banana, avocado, cassava, onion, oil palm, chili, papikra, blueberry, coffee, cacao, grapes, quinoa, olive, citrus and others. All of them have challenges in production in their specific agroecosystems under stress due to pests, diseases, salinity, drought, cold among others. Gene editing through CRISPR/Cas is a key tool for addressing critical challenges in agriculture by improving resilience to biotic and abiotic stress, increasing yield and enhancing the nutritional value of the crops. This approach allows precise mutation on site-specific gene at the DNA level, obtaining desirable traits when its function is altered. The CRISPR/Cas system could be used as a transgene-free genome editing tool when the ribonucleoprotein (RNP) acts as a carrier to delivered the CRISPR/Cas components into the plant cell protoplasts, or when the tRNA-like sequence (TLS) motifs are fused to single-guide RNA (sgRNA) and Cas mRNA sequence and expressed in transgenic plants rootstock to produce "mobile" CRISPR/Cas components to upper tissue (scion). Those innovations could be a potential approach to strengthen the Peruvian agriculture, food security and gricultural economy, especially in the tropical, Andean and coastal regions. This review article examines the advances and strategies of gene editing, focusing on transgene-free methodologies that could be adopted for research, development and use, and also identifies potential applications in key crops for Peru and analyzes their impact in the productivity and reduction of agrochemicals dependence. Finally, this review highlights the need to establish regulatory policies that strengthen the use of biotechnological precise innovations, ensuring the conservation and valorization of agrobiodiversity for the benefit of Peruvian farmers
Predicting gene distribution in ammonia-oxidizing archaea using phylogenetic signals
Full text linkPhylogenetic conservatism of microbial traits has paved the way for phylogeny-based predictions, allowing us to move from descriptive to predictive functional microbial ecology. Here, we applied phylogenetic eigenvector mapping to predict the presence of genes indicating potential functions of ammonia-oxidizing archaea (AOA), which are important players in nitrogen cycling. Using 160 nearly complete AOA genomes and metagenome assembled genomes from public databases, we predicted the distribution of 18 ecologically relevant genes across an updated amoA gene phylogeny, including a novel variant of an ammonia transporter found in this study. All selected genes displayed a significant phylogenetic signal and gene presence was predicted with an average of >88% accuracy, >85% sensitivity, and >80% specificity. The phylogenetic eigenvector approach performed equally well as ancestral state reconstruction of gene presence. We implemented the predictive models on an amoA sequencing dataset of AOA soil communities and showed key ecological predictions, e.g. that AOA communities in nitrogen-rich soils were predicted to have capacity for ureolytic metabolism while those adapted to low-pH soils were predicted to have the high-affinity ammonia transporter (amt2). Predicting gene presence can shed light on the potential functions that microorganisms perform in the environment, further contributing to a better mechanistic understanding of their community assembly