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Acoustic seal deterrents in mitigation of human–wildlife conflicts in the whitefish fishery of the River Iijoki in the northern Baltic Sea area
Get PDFRecovery of many seal populations has intensified seal-fishery conflicts. Acoustic deterrent devices (ADDs), designed to deter seals while minimising collateral harm, provide a potential solution. We investigated feasibility of ADDs to protect a European whitefish (Coregonus lavaretus) fishery in the River Iijoki, Finland, which enters the Baltic Sea. A sound barrier produced by a line of ADDs across the river efficiently prevented grey (Halichoerus grypus) and ringed (Pusa hispida) seals from passing the barrier line, thereby increasing catches, decreasing damage to fishing gear and catch and resulting in fewer seal sightings in the area safeguarded by ADDs. Hence, blocking access of seals to a river or its section by ADDs during a critical fishing period is a promising method for reducing seal-induced catch losses. However, long-term assessments of impacts of ADDs are still needed to verify the overall effectiveness.202
High organic carbon content constricts the potential for stable organic carbon accrual in mineral agricultural soils in Finland
Get PDFSequestering carbon into agricultural soils is considered as a means of mitigating climate change. We used agronomic soil test results representing c. 95% of the farmed land area in Finland to estimate the potential of the uppermost 15 cm soil layer of mineral agricultural soils to sequester organic carbon (OC) and to contribute to the mitigation of climate change. The estimation of the maximum capacity of mineral matter to protect OC in stable mineral-associated form was based on the theory that clay and fine-sized (fines = clay + silt) particles have a limited capacity to protect OC. In addition, we used the clay/OC and fines/OC ratios to identify areas with a risk of erosion and reduced productivity, thus indicating priority areas potentially benefitting from the increased soil OC contents. We found that 32–40% of the mineral agricultural soils in Finland have the potential to further accumulate mineral-associated OC (MOC), while in the majority of soils, the current OC stock in the uppermost 15 cm exceeded the capacity of mineral matter to protect OC. The nationwide soil OC sequestration potential of the uppermost 15 cm in mineral agricultural soils ranged between 5 and 10 Tg, which corresponds to less than the annual greenhouse gas emissions in Finland. The fields with the highest potential for SOC accrual were found in the southern and southwestern parts of the country, including some of the most intensively cultivated high-clay soils. Although the nationwide potential for additional OC sequestration was estimated to be relatively small, the current OC storage in Finnish arable mineral soils (0-15 cm) is large, 128 Tg. Farming practices enabling maximum OC input into the soil play an important role as a tool for mitigating the loss of carbon from high-OC soils in the changing climate. Furthermore, especially in high-clay areas with potential for MOC accrual, efforts to increase soil OC could help improve soil structural stability and therefore reduce erosion and the loss of nutrients to the aquatic environments.202
Cultivation of forage maize in boreal conditions : Assessment of trade-offs between increased productivity and environmental impact
Get PDFThe cultivation of whole crop forage maize (Zea mays L.) for cattle feed has a potential for increased forage yield while reducing nitrogen (N) fertilisation compared to perennial grass-based systems. However, the possible environmental trade-offs of forage maize cultivation remain unknown in the boreal region due to the short growing season which limits cultivation practices. The aim of this study was to compare the environmental impact of forage maize with more widely cultivated forage crops in Finland that include perennial silage grass mixtures and whole crop spring cereal harvested as silage. The use of plastic mulch film in forage maize cultivation was included in the assessment as well. A life cycle assessment (LCA) was conducted including impact categories for global warming potential; marine and freshwater eutrophication; terrestrial acidification; freshwater, marine and terrestrial ecotoxicity; land use; and fossil resource depletion. Additionally, soil organic carbon (SOC) stock changes under long-term cultivation of the studied forage crops were simulated with the C-TOOL and Yasso20 models with methodological comparisons. The only clear differences between the studied crops were that the land use was lower (−26–48%) for forage maize, and the freshwater eutrophication (+59–67%) and terrestrial acidification (+10–57%) were higher for perennial grasses compared with other forages. A risk for decreased SOC stock under continuous forage maize cultivation was observed. Forage maize could be used to supplement perennial grass cultivation without major associated environmental risks. Future research shall be conducted on the effect of forage choices on the environmental impact of boreal dairy milk production and on decreasing the current high uncertainty associated with nitrous oxide (N2O) emission factors and SOC stock modelling choices.202
Blackcurrant press cake by-product: increased chemical bioaccessibility and reduced antioxidant protection after in vitro simulation of gastrointestinal digestion
Get PDFThis study describes the bioaccessibility in terms of total phenolic content (TPC) and antioxidant capacity before and after in vitro digestion from blackcurrant press cake extracts (BPC) and the bioactivity in cell culture, human erythrocytes as well as the in silico analysis. Chemical analysis of BPC presented an increase in TPC (270%) and anthocyanins (136%) after in vitro digestion, resulting in an improvement of antioxidant activity (DPPH 112%; FRAP: 153%). This behavior may be related to the highest activity of cyanidin-3-rutinoside, as confirmed by in silico analysis. The digested BPC did not exert cytotoxicity in cells and showed less antioxidant activity against the oxidative damage induced in endothelial cells and human erythrocytes compared to the non-digested extract. The results raise a question about the reliability we should place on results obtained only from crude samples, especially those that will be used to produce foods or nutraceuticals.202
Mapping multi-dimensional variability in water stress strategies across temperate forests
Get PDFIncreasing water stress is emerging as a global phenomenon, and is anticipated to have a marked impact on forest function. The role of tree functional strategies is pivotal in regulating forest fitness and their ability to cope with water stress. However, how the functional strategies found at the tree or species level scale up to characterise forest communities and their variation across regions is not yet well-established. By combining eight water-stress-related functional traits with forest inventory data from the USA and Europe, we investigated the community-level trait coordination and the biogeographic patterns of trait associations for woody plants, and analysed the relationships between the trait associations and climate factors. We find that the trait associations at the community level are consistent with those found at the species level. Traits associated with acquisitive-conservative strategies forms one dimension of variation, while leaf turgor loss point, associated with stomatal water regulation strategy, loads along a second dimension. Surprisingly, spatial patterns of community-level trait association are better explained by temperature than by aridity, suggesting a temperature-driven adaptation. These findings provide a basis to build predictions of forest response under water stress, with particular potential to improve simulations of tree mortality and forest biomass accumulation in a changing climate.202
Genome of Methylomonas sp. AM2-LC, representing a methanotrophic bacterial species isolated from water column of a boreal, oxygen-stratified lake
Get PDFMethanotrophic bacteria are a special group of bacteria that consume methane as their energy and carbon source. They are roughly divided into aerobic gammaproteobacterial, alphaproteobacterial and verrucomicrobial methanotrophs (that use O2 as their primary electron acceptor), and anaerobic bacteria of genus Candidatus Methylomirabilis (that use nitrite to oxidize methane) (Guerrero-Cruz et al., 2021). Methanotrophic bacteria play a crucial role in reducing the methane emissions from natural methanogenic ecosystems, like rivers, lakes and wetlands (Hanson and Hanson, 1996). They are also actively harnessed for their biotechnological potential to mitigate methane emissions from anthropogenic ecosystems (e.g., biofilters at landfills) and to convert methane in biogas and natural gas into various value-added products (e.g., single-cell protein and bioplastics) (Strong et al., 2015).
Comparative genomics of bacteria form the basis of the current bacterial taxonomy, like that of methanotrophic bacteria (Orata et al., 2018). In addition to comparative analysis, genome sequences of methanotroph isolates provide an important backbone database for taxonomic and functional analysis of the vast and constantly increasing shotgun metagenomic data, especially metagenome-assembled genomes (MAG) of putative methanotrophs, collected from environment (Buck et al., 2021; Khanongnuch et al., 2023). Furthermore, genomic data provide crucial insights into potentially novel and testable metabolisms in methanotrophic bacteria, relevant both to the understanding of environmental methane cycling and for biotechnological applications, such as fermentation, i.e., conversion of methane to organic acids and H2 (Kalyuzhnaya et al., 2013), denitrification (Kits et al., 2015), extracellular electron transfer (Zheng et al., 2020), and oxidation of alternative electron donors (Gwak et al., 2022). Genetic engineering of methanotrophs to enhance their methane consumption and bioconversion efficiencies, and to increase the range of methane-derived products, also benefit greatly from the genomic data (Henard and Guarnieri, 2018; Jeong et al., 2023).
Here, we report the genome sequence of a strain Methylomonas sp. AM2-LC, which was isolated from the water column of a boreal, humic, O2-stratified lake, located in Southern Finland. It represents a putatively novel species of Methylomonas sp., a methanotroph genus widely present in various methanogenic ecosystems (Bussmann et al., 2021; Danilova et al., 2013; Hoefman et al., 2014; Ogiso et al., 2012; Zhu et al., 2020), and an attractive methane bioconversion candidate (Patel et al., 2018; Patel et al., 2022; Tikhonova et al., 2023).202
Genetic diversity insights from population genomics and machine learning tools for Nordic Arctic charr (Salvelinus alpinus) populations
Get PDFArctic charr (Salvelinus alpinus) is a salmonid species of high ecological and commercial value in the Holarctic region. Nevertheless, more information is needed about its underlying genetic diversity and population structure in the Nordics, especially regarding farmed populations. High-throughput sequencing was applied in three Arctic charr populations of anadromous or landlocked origin from Finland, Norway and Sweden. More specifically, the animals from the Swedish and Norwegian populations originated from a major egg supplier and producer, respectively. Furthermore, in the case of the Finnish population, the sampled animals originated from the only active conservation program for Arctic charr in the country with a potential interest in farming. Using double-digest restriction site-associated DNA sequencing (ddRAD-seq) on more than 500 fish, over 2000 single nucleotide polymorphisms (SNPs), both in the form of individual SNPs and as read haplotypes, were used to study the genetic diversity and structure of those populations. Genetic diversity metrics were similar between the Norwegian and the Swedish populations. However, substantially lower (40–50 %) genetic diversity was found in the Finnish population. Moreover, considerable genetic differentiation was implied between the studied populations as the mean fixation index (FST) was above 0.1 in all pairwise comparisons. All populations were easily discernible through either principal component analysis (PCA) or discriminant analysis of principal components (DAPC). In addition, unsupervised machine learning models such as K-means, Gaussian and Bayesian Gaussian mixtures were assessed for their ability to detect genetic clusters. A preceding dimensionality reduction step by PCA resulted in all three models, suggesting that the most probable number of clusters was three. Overall, our study affirmed the utility of the developed ddRAD-seq genotyping method and unveiled the genetic structure of the studied populations, both of which could contribute to their more efficient management by captive breeding.202
Kohti maatalouden kestävää rahoitusta : maatalousyrittäjien ja pankkien rahoitusneuvottelijoiden näkemyksiä
No full text202
Shifts in soil C stabilization mechanisms are linked to reindeer-induced changes in plant communities and associated fungi in subarctic tundra
Get PDFArctic tundra ecosystems store a significant proportion of the global soil organic carbon (C). However, warming-induced shrub encroachment and reindeer (Rangifer tarandus L.) grazing regimes promoting graminoid vegetation may strongly influence tundra soil C stability. Here, we studied how reindeer grazing intensity and experimental warming affect soil C stabilization in a tundra ecosystem. We hypothesized that under light grazing, persistent complexes formed by fungal necromass (FNM) and condensed tannins (CT) from shrub roots stabilize the soil C, whereas, under heavy grazing, the soil C stabilization is affected by glomalin-related soil proteins (GRSP) produced by arbuscular mycorrhizal fungi of graminoids. In addition, we expect warming to mediate grazing effects, diminishing the potential for C stabilization.
Our results show no effect of grazing on stable C concentration, however, under light grazing the labile C concentration was higher. We found higher concentrations of chitin and tannins under light grazing, indicative of soil C stabilization potential through FNM-CT complexes. By contrast, we found more root ergosterol under heavy grazing, suggesting a high abundance of endophytes, usually melanized, and a slightly higher GRSP concentration. Warming did not cause changes in stable C concentration but was associated with changes in the soil chemical quality, pointing to a decrease of lignin, polypeptides, and polysaccharides.
We conclude that different soil C stabilization mechanisms operate under light and heavy grazing pressures and that these mechanisms are closely linked to changes in the vegetation and the fungi typically associated with them.202