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Controls on spatial and temporal variability of soil moisture across a heterogeneous boreal forest landscape
No full textIn light of climate change and biodiversity loss, modeling and mapping soil moisture at high spatiotemporal resolution is increasingly crucial for a wide range of applications in Earth and environmental sciences, particularly in boreal forests, which play a key role in global carbon cycling, are highly sensitive to hydrological changes, and are experiencing rapid warming and more frequent disturbances. However, modeling and mapping soil moisture dynamics is challenging due to the nonlinear interactions among numerous physical and biological factors and the wide range of spatial and temporal scales at play. This study aims to identify key spatial and temporal controls on soil moisture using an empirically based modeling approach. We focused on a boreal forest landscape in northern Sweden, where we monitored surface soil moisture with dataloggers at 78 locations during the summer of 2022. We investigated the relationships between observed soil moisture variations and numerous environmental and meteorological predictors from multiple sources at varying spatial resolutions and temporal scales, and we assessed how these relationships changed over time. Spatial variation in soil moisture was influenced not only by topography and by the spatial resolution used to represent it, but also by soil properties, vegetation, and land use/land cover (LULC). In addition, the relative importance of these factors changed over time, with topography generally explaining more spatial variation during wet periods, while soil and vegetation were more relevant during dry periods. This suggests that current soil moisture maps relying primarily on topographic indices could benefit from integrating soil, vegetation, and LULC information to better capture spatial variability under different wetness conditions, as well as from selecting the optimal spatial resolution for the specific area of interest. Temporal variation in soil moisture was better explained by hydrological and meteorological variables averaged over 5 to 7 d preceding soil moisture measurements, highlighting the importance of accounting for both lagged and cumulative effects of weather conditions. Field predictors generally outperformed remote sensing and modeled predictors, indicating that soil moisture mapping based solely on spatially continuous predictors requires improving spatial detail of maps describing soil texture, structure, and organic matter content. Our findings contribute to improving the accuracy and interpretability of data-driven methods, such as machine learning, for mapping soil moisture across space and time for forest management and nature conservation
Changes in silver birch biochemical profiles and leaf-associated fungi across genetic markers induced by seed treatment with DBD plasma
No full textNew approaches are needed in the forestry sector to improve tree resistance to various biotic and abiotic stress factors and mitigate their negative impacts on forest health. This study aimed to evaluate the effect of seed treatment with the dielectric barrier discharge (DBD) plasma on the changes in biochemical processes and fungal communities of silver birch (Betula pendula Roth.), considering tree half-sib families. The potential of DBD plasma treatment for the modulation of birch seedling properties was estimated in seven selected half-sib families by analysis of the composition of biochemical compounds (from first and second vegetation leaf samples) and fungal communities (from second vegetation leaf samples). Seed treatment with DBD plasma has potential to enhance bioactive compounds, reduce fungal pathogens, thereby improving silver birch seedling traits. The families 73 and 86 demonstrated the most distinct responses to 2-minute-DBD plasma treatment. The activity of antioxidant enzymes (CAT, APX, and GR) increased by-50 % in the 73 family (the first vegetation), and by-39 % in the 86 family (the second vegetation). The increase in flavonoid (by similar to 44 % in the first vegetation and by similar to 30 % in the second vegetation) and photosynthetic pigment amounts (by-55 % in the first vegetation and by-60 % in the second vegetation) was also determined. The family 86 exhibited a reduced relative abundance of the most abundant pathogen, Phyllactinia betulae. In the current study, the effect of silver birch seed treatment with DBD plasma on leaf samples was investigated at multiple levels, including biochemical, metagenomic, and genetic aspects
Partitioning Beta Diversity at Two Spatial Resolutions Reveals Biotic Homogenisation With Habitat Degradation
No full textAim: Understanding the effects of habitat degradation on biodiversity is essential for undertaking conservation initiatives, but commonly used metrics of biodiversity, like species richness and beta diversity, can miss important signals of change. Greater insights can be gained by partitioning beta diversity into nestedness, which relates to species loss, and turnover, which relates to species replacement. To obtain a more comprehensive understanding of biodiversity change with habitat degradation, we investigate how nestedness and turnover vary when comparing assemblages from the same or different habitat degradation levels, and how assemblage aggregation resolution influences this relationship. Location: Sweden. Methods: We used beta diversity partitioning to assess lichen, fungi and bryophyte species composition from 120 forest sites across Sweden, from three different habitat degradation levels, and at two aggregation scales (pairwise local assemblages and assemblages pooled at the habitat degradation level across our study sites). We examined how pairwise total beta diversity, nestedness and turnover varied when comparing assemblages from sites of either the same or different habitat degradation levels. In addition, we examined the relationship between total beta diversity, nestedness and turnover when assemblages pooled at the habitat degradation level were compared. Results: We detected a small increase in pairwise lichen total beta diversity (Cliffs delta 0.40) and nestedness (Cliffs delta 0.19), but not in any other pairwise comparisons. In contrast, for all taxa, comparisons between assemblages pooled at the habitat degradation level showed higher values of nestedness and lower values of turnover than the corresponding pairwise comparisons, suggesting biotic homogenisation in highly degraded sites. Main Conclusions: Our results highlight the importance of considering biodiversity change across multiple spatial resolutions to fully capture the effects of local species replacements in highly degraded habitats on biotic homogenisation
Establishment and production of lucerne ( Medicago sativa L.) in Sweden is affected by inoculation product choice
Get PDFLucerne (Medicago sativa L.) is an important perennial forage legume in Sweden, but its potential cultivation area is constrained by uncertainty of successful establishment. This study aimed to identify management practices that could lead to improved establishment of lucerne. Lucerne cultivar SW Nexus was grown at four different locations in southern Sweden over two establishment/production cycles. At all locations except Svalov, lucerne had not previously been cultivated in the plot location for at least seven years. Inoculation treatments of one standard rhizobia (Nitragin Gold, NG), two NG-related, three NGs combined with single micronutrient, and six alternative inoculants were assessed in comparison with a no inoculation control for their effects on lucerne establishment and production. The results showed that alternative inoculants were sometimes better than the standard inoculants. The largest contrast between different inoculation treatments was at R & aring;dde in the first crop cycle, where the best treatment yielded 12000 kg DM ha-1 across three harvests, nearly twice that of the control, and all alternative inoculant treatments had higher total nitrogen concentration (TN), lower carbon to nitrogen ratio (C:N), and greater normalised difference vegetation index (NDVI) than the control. There was no evidence that the soil-applied micronutrients improved yield at any location. At Svalov, where lucerne had previously been grown, there was no effect of any of the treatments. In conclusion, inoculation is essential at locations where there is no history of lucerne cultivation, and choice of inoculation product can affect establishment and production
Deep learning-enhanced detection of road culverts in high-resolution digital elevation models: Improving stream network accuracy in Sweden
Get PDFStudy region: Sweden, a mostly forested country with many small forest roads obstructing topographical modelling of shallow groundwater and streams. Study focus: Maps have traditionally been constructed from aerial photos, but dense forest canopies often obscure these streams from view. Topographical modelling is a widely adopted method for mapping small streams and has been proposed as a potential solution. However, road embankments can disrupt flow paths, acting like dams in the digital landscape. This study presents a novel method where a unique dataset of 28,512 culverts was used to develop a deep learning method to map road culverts, enabling the correction of digital elevation models and enhancing the accuracy of topographically derived stream networks. New hydrological insights for the region: The deep learning model successfully mapped 87 % of all culverts in the test data, and integrating these predicted culverts into topographical models slightly improved the precision of stream networks extracted from high-resolution digital elevation models in the region. These findings demonstrate the possibility for UNet models to enhance hydrological modelling and stream network mapping but further research should focus on reducing the number of false positive culvert predictions
Future Wood Availability in Europe in Light of Climate and Energy Policy and Geopolitical Developments—A Wood Resource Balance-Based Assessment
Get PDFThe amended European Union (EU) Renewable Energy Directive—in aiming to increase the share of renewable energy in overall energy consumption—promotes an increased demand for wood, while the EU’s updated Land Use, Land-Use Change, and Forestry (LULUCF) Regulation sets ambitious, binding national targets for the increase in net greenhouse gas removals that could restrict the supply of wood. Additionally, the ongoing war in Ukraine has directly affected the availability of woody biomass in Europe through the EU’s import ban on timber and timber products from Russia and Belarus. This paper provides an in-depth comparative analysis of sources and uses of woody biomass in four European regions in light of these recent climate and energy policies and geopolitical developments. The analysis indicates significantly underestimated reported removals in three of the four European regions studied. Further, projections suggest policy incoherence between current climate and energy objectives until 2030 in all four regions, as fellings increase at a faster rate than net annual increment in all four regions, decreasing the forest carbon sink and thus making it all but impossible to reach the 2030 target of the LULUCF regulation. However, between 2030 and 2040, energy-related fellings could decrease in regions north and west, while they could continue to grow in regions east and south, albeit at a lower rate
Risk Assessment as a Tool to Improve Water Resource Management
Get PDFThe examination of primary risk assessment methodologies reveals a significant expansion in recent years, particularly toward encompassing ecosystem preservation and predictive models for environmental contaminant behavior. However, alongside this progress, new challenges have surfaced, such as engineered nanoparticles, cumulative impacts, and the risks associated with emerging contaminants of concern. This research aims to uncover fresh perspectives within the realm of global environmental risk assessment concerning the stress on water resources. Based on the results, the directions for studying water pollution's environmental risks are highlighted. Special attention is given to water multi-stressor challenges with significant impact and therefore to multi-risk assessment of aquatic ecosystem components and human health. The foundational framework for the primary phases of risk assessment was delineated, taking into account the existing body of prior research. Drawing from the current state of knowledge, the notion of evaluating cumulative ecological risks (termed multi-risk) stemming from pollutant exposure, encompassing emerging contaminants among other factors, is introduced. This encompasses the phases of contaminant migration, transformation, and accumulation within the various components of the hydrosphere, specifically in surface water bodies, groundwater, and their eventual discharge into the sea and ocean, within a unified global water system. Furthermore, alternative approaches for incorporating additional factors, such as climate change, into the overarching risk assessment framework have been pinpointed, offering novel perspectives for future research endeavors in this domain
Liming-induced taxonomic homogenization of chironomid assemblages in Scandinavian lakes as unraveled by paleolimnological reconstructions
Get PDFIn the 1980s, liming became a large-scale, governmentally supported restoration program implemented by many countries to mitigate the effects of acidification of freshwaters. Despite some 50 years of liming of thousands of lakes and streams, its efficacy remains largely debated. This study is the first of its kind to use paleolimnological reconstructions using both subfossil chironomid assemblages and their carbon stable isotopic composition to compare the ecological trajectories of limed and control (unlimed) lakes over the last 100 years in order to unravel the effects of liming on Scandinavian lakes. Our study revealed strong effects of liming on lake water chemistry and sedimentary characteristics of limed lakes. Overall, higher present-day pH values were observed in lake water of the limed lakes (average pH of 6.7 +/- 0.2) than in control lakes (average pH of 5.9 +/- 0.5), and the pH variability was much lower among limed lakes. A decrease in the dissimilarity of the chironomid assemblages among limed lakes was also observed as liming progressed, and the degree of dissimilarity after liming was largely lower than pre-acidified levels. This pattern suggests that liming favoured the selection of similar chironomid taxa in limed lakes, thus providing complementary empirical evidences about the effects of liming on aquatic communities through taxonomic homogenization of chironomid assemblages. As the ecological trajectories of limed and control lakes strongly differed, our study also questions the impact of liming on the resilience of Scandinavian lakes and, importantly, their ability to cope with ongoing and future climatic and environmental changes. Finally, isotope-based results indicated that liming masks potential complex effects on carbon flows at the base of the food web by shifting algal carbon isotopic baselines. The use of carbon stable isotope analysis of chironomid head capsules to study the effects of liming on energy flows within lake food webs is, therefore, not suitable
Nutrient use and methane emissions in growing beef fed different protein sources and a pasture-based diet
Get PDFThis study investigated the effects of different protein sources on feed intake, nutrient, and energy utilization, growth performance, and enteric methane (CH4) emissions in growing beef cattle, also evaluated against a pasture-based diet. Thirty-two Holstein x Angus growing beef were allocated to four dietary treatments: a total mixed ration (TMR) including solvent-extracted soybean meal as the main protein source (n = 8), TMR with local brewers' spent grains (n = 8), TMR with local field beans (n = 8), and a diet consisting solely of fresh-cut Italian ryegrass (GRA; n = 8). Every 4 wk, animals were moved to digestibility stalls within respiration chambers to measure nutrient intakes, energy and nitrogen (N) utilization, and enteric CH4 emissions. Feed intake (Calan gates), nutrient intakes, and CH4 emissions (GreenFeed) were also measured when animals were group-housed. In respiratory chambers, enteric CH4 yield per kg of dry matter intake (DMI), per kg of organic matter intake (OMI), and per kg body weight were lower (P < 0.05) for GRA. Feces and urine energy outputs were higher (P = 0.007 and P < 0.001, respectively) for GRA steers than concentrate-fed steers. Urinary nitrogen output (UNO, P = 0.026), manure (feces + urine) nitrogen output (MNO, P = 0.034), UNO/nitrogen intake (P = 0.002), and MNO/nitrogen intake (P = 0.006) were higher for GRA. During group-housing periods, CH4 emissions, measured by GreenFeed, were similar to those measured in chambers. Similar CH4 yield between treatments, expressed per kg digestible DMI and digestible OMI, may indicate that the lower diet digestibility was likely the reason for the reduced enteric CH4 emissions in pasture-based diets. The higher energy output and nitrogen losses, and the reduced nitrogen utilization for steers fed the fresh-cut ryegrass diet indicate less efficient energy and nitrogen utilization, which can be considered environmentally undesirable. The lower growth rates in the pasture-based system should also be accounted for when this is adopted for reducing production costs
Genetic Variability of Ethiopian Chickpea (Cicer arietinum L.) Landraces for Acid Soil Tolerance
Get PDFChickpea is among the major legume crops grown globally. In Ethiopia, it plays a vital role in the food security and economic stability of smallholder farmers. However, its production is often hampered by abiotic factors, particularly soil acidity, which is a major yet often overlooked challenge. Using tolerant genotypes alone or combined with soil amendments is a sustainable approach to improving chickpea production in acidic soils. Hence, the present study assessed the genetic variation of 64 Ethiopian chickpea accessions for acidic-soil tolerance using simple lattice design-based field experiments with two replications at two sites with acidic soil, Emdebir and Holetta. The study revealed significant genetic variation among the evaluated accessions for acid soil tolerance. The study also identified tolerant and high-yielding chickpea accessions with a high yield stability index (YSI) at both test sites. The landrace ETC_B_1_2016 exhibited the highest number of primary branches per plant (NPB), number of pods per plant (NPP), and total seed yield (TSY) at the Emdebir acidic soil trial. At the Holetta acidic soil trial, the landrace ETC_41237 recorded the highest TSY, followed by ETC_K_3_2016 and ETC_B_1_2016, while Akaki had the least. In addition, 14 accessions had the highest TSY and YSI at the Emdebir site, while 16 had the highest YSI at the Holetta site. Notably, NPP displayed the strongest positive correlation with TSY at both sites, irrespective of lime application. Higher genetic variance and broad-sense heritability observed for NPP, hundred-seed weight (HSW), and TSY suggest that genetic factors mainly influence these traits and are more likely to improve through selection. The identified acid-tolerant and high-yielding accessions could be considered for direct cultivation in areas with acidic soils, potentially increasing chickpea productivity. Additionally, these accessions can be crossbred with existing improved varieties to enhance their adaptability to acidic soils, ultimately contributing to food security in regions affected by soil acidity