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European forests are under increasing pressure from global change-driven invasions and accelerating epidemics by insects and diseases
Get PDFRising temperatures attributed to anthropogenic climate change have held a firm grip on European forests for over two decades now and disturbances have increased substantially, mainly from insects and pathogens. Empirical evidence suggests a direct linkage between rising temperatures and increasing damage from native insects. Although the rapid spread of non-native invasive pests and pathogens is mainly driven by globalized trade and lacking tree species adaptation to locally new threats, climate change favors rapid range expansion of some invasive pests. Here, we present some examples of tree-insect-pathogen interactions in native and non-native systems that have experienced climate change-induced severe outbreak dynamics. We document the spread of damaging insects and pathogens into previously climatically unsuitable regions and underscore the severe forest damages such species distribution shifts can cause. Although systematic assessments are still pending, the information provided here by multiple independent empirical evidences is highly valuable for identifying some of the most pressing issues in European forest protection. Our work can guide forest protection agencies in preparing mitigating strategies for upcoming decades
Climate change impacts to foraging seascapes for a highly migratory top predator
Get PDFBackgroundClimate change is impacting the distribution and movement of mobile marine organisms globally. Statistical species distribution models are commonly used to explain past patterns and anticipate future shifts. However, purely correlative models can fail under novel environmental conditions, or omit key mechanistic processes driving species habitat use.MethodsHere, we used a unique combination of laboratory measurements, field observations, and environmental predictors to investigate spatial variability in energetic seascapes for juvenile North Pacific albacore tuna (Thunnus alalunga). This species undertakes some of the longest migrations of any finfish, but their susceptibility to climate-driven habitat changes is poorly understood. We first built a framework based on Generalized Additive Models to understand mechanisms of energy gain and loss in albacore, and how these are linked to ocean conditions. We then applied the framework to projections from an ensemble of earth system models to quantify changes in thermal and foraging habitats between historical (1971-2000) and future (2071-2100) time periods.ResultsWe show how albacore move seasonally between feeding grounds in the California Current System and the offshore North Pacific, foraging most successfully in spring and summer. The thermal corridors used for migration largely coincide with minimum metabolic costs of movement. Future warming may result in loss of favorable thermal habitat in the sub-tropics and a reduction in total habitat area, but allow increased access to productive and energetically favorable sub-arctic ecosystems. Importantly, while thermal considerations suggest a loss in habitat area, forage considerations suggest that these losses may be offset by more energetically favorable conditions in the habitat that remains. In addition, the energetic favorability of coastal foraging areas may increase in future, with decreasing suitability of offshore foraging grounds. Our results clearly show the importance of moving beyond temperature when considering climate change impacts on marine species and their movement ecology.ConclusionsConsidering energetic seascapes adds essential mechanistic underpinning to projections of habitat gain and loss, particularly for highly migratory animals. Overall, improved understanding of mechanisms driving migration behavior, physiological constraints, and behavioral plasticity is required to better anticipate how climate change will impact pelagic marine ecosystems
Variations in Ecosystem-Scale Methane Fluxes Across a Boreal Mire Complex Assessed by a Network of Flux Towers
Get PDFHigh latitude mires are key ecosystems in the context of climate change since they store large amounts of carbon while constituting an important natural source of methane (CH4). However, while a growing number of studies have investigated methane fluxes (FCH4) at the plot- (similar to 1 m(2)) and ecosystem-scale (similar to 0.1-0.5 km(2)) across the boreal biome, variations of FCH4 magnitudes and drivers at the mesoscale (i.e., 0.5-20 km(2)) of a mire complex are poorly understood. This study leveraged a network of four eddy-covariance flux towers to explore the spatio-temporal variations in ecosystem-scale FCH4 across a boreal mire complex in northern Sweden over 3 years (2020-2022). We found a consistent hierarchy of drivers for the temporal variability in FCH4 across the mire complex, with gross primary production and soil temperature jointly emerging as primary controls, whereas water table depth had no independent effect. In contrast, peat physical and chemical properties, particularly bulk density and C:N ratio, were identified as significant baseline constraints for the spatial variations in FCH4 across the mire complex. Our observations further revealed that the 3-year mean annual FCH4 across the mire complex ranged from 7 g C m(-2) y(-1) to 11 g C m(-2) y(-1), with a coefficient of variation of 16% that is similar to the variation observed among geographically distant mire systems and peatland types across the boreal biome. Thus, our findings highlight an additional source of uncertainty when scaling information from single-site studies to the mire complex scale and beyond. Furthermore, they suggest an urgent need for peatland ecosystem models to resolve the mesoscale variations in FCH4 at the mire complex level to reduce uncertainties in the predictions of peatland carbon cycle-climate feedbacks
Sensory evaluation and consumer acceptance of Kisra, a sudanese fermented flatbread made with biofortified sorghum: Insights from check-all-that-apply (CATA) method
Get PDFKisra, a traditional fermented bread made from sorghum flour, is gaining prominence in Sudan’s local food industry. This study evaluated the sensory attributes of nine Kisra products prepared from five sorghum cultivars, including the biofortified Dahab variety, rich in iron and zinc. Cultivars tested included Wad Ahmed, DabarTabat, Korokolo, and Arfagadamek-8, along with their 1:1 blends with Dahab. Skilled local women prepared the Kisra to ensure authenticity. Sensory characteristics such as appearance, taste, texture, color, and aftertaste were evaluated by 102 Kisra consumers using hedonic and check-all-that-apply (CATA) tests. Data were analyzed using ANOVA, Tukey’s test, hierarchical clustering, and correspondence analyses. Results revealed a preference for Kisra made from Dahab and Daber due to appealing traits like sweetness, smoothness, and porousness. Conversely, Korokolo and Arfagadamek-8 were less favored for their bitterness and coarseness. Consumer segmentation analyses highlighted Dahab’s ability to meet sensory and nutritional needs. This study underscores the potential of biofortified sorghum in improving traditional fermented foods while addressing nutritional and sensory preferences, paving the way for more nutritious products in Sudan
Den odlade laxens tillväxt och överlevnad i havet som post-smolt
Get PDFÅterfångster av Carlin-märkt tvåårig odlad laxsmolt (Salmo salar) under perioden 1960–1984 visar på ett tydligt samband mellan kroppslängd och havsöverlevnad. Överlevnaden ökar gradvis från 13 cm till ca 20 cm där den planar ut. Ett liknande överlevnadsmönster kan ses för PIT-tag märkt tvåårig laxsmolt från Umeälven utplanterade under åren 2011–2019. Ettårig smolt har en storlek av 13–16 cm och uppvisar generellt mycket låg havsöverlevnad. Det finns således starka evidens för att odlad laxsmolt bör vara ca 20 cm lång eller större vid utsättning för att havsöverlevnad ska optimeras. Syftet med denna kunskapssammanställning är att utreda den odlade post-smoltens tillväxt och överlevnad under det första halvåret i havet, samt hur den är kopplad till födosituation och predationsrisk. Sambandet mellan smoltens kroppsstorlek vid utsättning och havsöverlevnad är i särskilt fokus. Födosituationen i havet under juni och juli är svår för post-smolt och medeltillväxten för populationen är mycket låg under perioden. En teoretisk simulering visar att det tar ca två månader för post-smolt att förbruka sina energireserver vid svält i sådan utsträckning att de riskerar att dö. Post-smoltens förmåga att klara en svältsituation är storleksberoende, där små individer är mer utsatta på grund av mindre energireserver och högre relativ standardmetabolism. Tvåårig smolt 20 cm eller större tål svält bättre och uppvisar god tillväxt från slutet av juli när strömmingsyngel blir tillgängliga i havet. De kan även välja ettårig strömming som byten under hösten vilket ytterligare förstärker födoresursen. Den mest kritiska perioden för predation av laxsmolt föreslås vara utsättningstillfället och under vandring mot havet. Uppgifter från olika studier visar att dödlighet till följd av predation kan ligga mellan 20–50 % av de utsatta fiskarna. Ett stort antal studier har visat att fåglar som skarv, måsfåglar och skrake kan utgöra en påtaglig risk för predation vid utsättning av odlad fisk. Alla dessa arter föredrar bytesfiskar mindre än 20 cm vilket därmed kan bidra till den observerade storleksberoende havsöverlevnaden. Även fiskar som gädda kan utgöra en påtaglig risk för predation men den är inte lika tydligt storleksberoende. Sälars roll som predator på post-smolt under första halvåret i havet är inte uppenbar utan de utgör troligen främst ett problem för adult lax i kustnära områden. Odlad lax saknar erfarenhet av olika typer av naturliga bytesdjur och predatorer. Det tar sannolikt en relativt lång tid i havet innan de når ett stadium av effektivt födointag och vet hur predatorer ska undvikas, vilket påverkar tillväxt och överlevnad under det första halvåret i havet. Sammanfattningsvis är kunskapen om post-smoltens liv i havet till stora delar okänt och mer studier behöves för att med större säkerhet kunna klargöra kunskapsluckor rörande födoval och predationsrisk i olika miljöer
Silicon-Mediated Modulation of Olive Leaf Phytochemistry: Genotype-Specific and Stress-Dependent Responses
Get PDFSecondary metabolites in olive (Olea europaea L.) leaves constitute a complex framework wherein phenylpropanoids, terpenoids, and secoiridoids in particular, serve as major contributors to olive plant resilience. Silicon (Si) stands as a mediator of defense mechanisms in plants, enhancing their protective responses and adaptability. A field trial on one-year-old plantlets of two metabolically distinct olive genotypes was conducted to investigate the effects of foliar-applied Si on the phytochemical profiles of locally treated leaves. Silicon's systemic effects in juvenile leaves were also appraised. We accounted for intervarietal differences in nutrient uptake and conducted in situ measurements of physiological indices. The peak of the summer season and the onset of autumn were chosen as the two sampling time points. Intense summer conditions prompted metabolic adjustments that resulted in phytochemical profiles unique to each cultivar. These profiles were further significantly altered by Si while remaining genotype-specific, with substantial increases in prominent compounds like oleuropein (105% and 252%) and verbascoside (62% and 126%), depending on the genotype. As the pressure from environmental factors eased, the differences in Si-mediated phytochemical responses emerged. Silicon had a limited effect on the phytochemical profile of the resilient cultivar which acquired a metabolic steady-state, while it significantly altered the profile of its metabolically more versatile counterpart, resulting with a progressive increase in its oleuropein (37%) and verbascoside (26%) levels. These effects extended to untreated, juvenile leaves as well. While effective in altering and improving the phytochemical composition of olive leaves, Si acted in a manner that adhered to each genotype's metabolic foundation. The intensity of environmental constraints, along with each cultivar's inherent sensitivity to them, seems to be tied to silicon's capacity to mediate significant phytochemical alterations. The extent of silicon's prophylactic function may therefore be dependent on a genotype's metabolic foundation and overall sensitivity, and as such it seems inseparable from stress and its intensity
Exploring the Diversity in Oil Content, Fatty Acid Profiles, and Seed Coat Color in Sudanese Sesame Germplasm: Implications for Breeding and Crop Improvement
Get PDFSesame, a key oilseed crop, thrives in arid environments and offers high-quality oils. Sudan, a major producer and center of sesame genetic diversity, remains underutilized in breeding efforts. This study analyzed 87 Sudanese sesame accessions, revealing significant variations in oil content, fatty acid composition, and seed coat color. The findings highlight the potential of Sudanese germplasm for improving oil quality and broadening trait diversity in breeding programs. Oil content ranged from 32.8% to 50.2%, with oleic acid (41.3%-47.6%) and linoleic acid (35.0%-41.4%) as the predominant fatty acids, consistent with other regions. Some samples showed exceptionally high oleic acid levels. Seed coat color varied significantly, particularly in lightness (L*), but it showed no correlation with oil content or fatty acid composition. Its potential link to bioactive compounds warrants further study. Principal coordinates analysis showed no link between oil levels, fatty acid profiles, and the original collection sites. The findings highlight the breeding potential of Sudanese sesame germplasm, particularly for developing varieties with high unsaturated fatty acids, such as oleic acid, and diverse seed coat colors. Further studies across environments and genetic investigations are needed to ensure trait stability and optimize their use
The Importance of Ditches and Canals in Global Inland Water CO2 and N2O Budgets
Get PDFDitches and canals are omitted from global budgets of inland water emissions, despite research showing them to be emitters of greenhouse gases (GHGs). Here, we synthesize data across climate zones and land use types to show, for the first time, that global ditches emit notable amounts of carbon dioxide (CO2) and nitrous oxide (N2O). Ditches had higher per-area emissions of CO2 and N2O than ponds, lakes, and reservoirs, likely due to high nutrient inputs. Preliminary upscaling showed that the inclusion of ditches would increase global inland water CO2 emissions by 0.6%-1% and N2O emissions by 3%-9%. Trophic state and climate influenced N2O emissions, while CO2 emissions had complex drivers difficult to disentangle at the global scale. This research highlights the importance of including ditches in global inland water GHG budgets and informs more accurate reporting of anthropogenic emissions in national inventories
How do trees outside forests contribute to human wellbeing? A systematic review from South Asia
Get PDFTrees have emerged as a key focus of global environmental policy. Several programs promote planting of trees outside forests (ToF), in places such as farms and grazing lands, due to the potential of trees to provide a wide variety of benefits to people and nature. Yet, our knowledge of human well-being outcomes of ToFs is limited, especially in South Asia. In this systematic literature review, we examine multidimensional human wellbeing outcomes of a wide range of ToF practices in rural landscapes of South Asian countries; including Bangladesh, India, Nepal, Pakistan and Sri Lanka. Relying on six databases, we uncover a large body of research in 325 articles considered for this review. Articles from Bangladesh and India dominate our review, with 71% of the studies. Further, two ToF systems, tree and forest gardens and multipurpose trees on farms, were the most commonly studied, accounting for approximately 43% of the dataset. About 62% of publications reported increases in incomes, representing economic wellbeing, 34% and 36% of publications reported an increase in material wellbeing (access to biomass and fuelwood respectively), and 10% in dietary diversity. ToF systems also created opportunities for vocational training. Trade-offs include negative and mixed outcomes on people's sense of agency, political voice, and social equity in particular with afforestation and monoculture plantation projects in which governmental agencies took leadership or influential roles. Some research designs were weak and it was unclear whether the studied tree-based systems reflect the actual distribution of tree-based systems in South Asia. This review offers useful insights to guide ongoing and future tree-based natural-climate solutions projects in the region and worldwide to ensure ecological security and human wellbeing are well considered. It also points to areas where future research is needed