98024 research outputs found
Sort by
Status of the Tana/Teno river salmon populations in 2024 : report from the Tana/Teno monitoring and research group
Full text linkNo increased drought-related mortality after thinning: a meta-analysis
Full text linkContext
Forest scientists are challenged to identify and propose evidence-based silvicultural options to mitigate the impacts of drought events induced by climate change. For example, it has been suggested that thinning increases soil water availability for individual trees by reducing stand density and stand-level transpiration. Many studies have assessed the impact of thinning on stem growth and transpiration of individual trees during and after drought events. Often, growth increases were observed, but not consistently, and their impact on tree survival following drought has rarely been addressed.
Aims
We aimed to assess the effect of thinning on tree mortality, the ultimate indicator of tree resistance to soil water deficit induced by drought, with a focus on dominant trees.
Methods
We conducted a risk ratio meta-analysis on tree mortality before and after an extreme drought event with 32 thinning experiments from nine studies in Europe and North America.
Results
We showed that thinning reduced the overall mortality risk of trees. However, the lower mortality rate in thinned stands relative to unthinned stands in pre-drought periods was not further reduced during and after extreme drought events (p > 0.05). This may be due to the large heterogeneity and inconsistent reporting of mortality across the studies included in our analysis. Thinning did not exacerbate mortality among dominant trees.
Conclusion
Since thinning did not increase mortality, its application can still be recommended for many other management objectives such as maintaining tree species richness or lower disturbance risks from windthrow. We propose better documentation of thinning trials to improve the data base for systematic reviews
Politiikkatoimet liikkuvien työkoneiden puhtaan siirtymän edistämiseksi : Työkoneiden päästöjen vähentäminen tukee suomalaisten työkonevalmistajien kilpailukykyä vientimarkkinoilla
No full textElm genetic resources conservation in Finland supplemented by dormant bud cryopreservation
No full textEvaluation of six phosphorus extraction methods for compliance testing of recycled P fertilizers
Full text linkPhosphorus (P) recycling for fertilizer production addresses the dependency on phosphate rock and mitigates P losses to the environment. However, predicting plant-available P in recycled fertilizers is challenging due to their diverse chemical composition. This study aimed at identifying the most suitable P extraction method for fertilizer compliance testing, considering their correlation with actual fertilization efficiency, as well as their simplicity, throughput, recognition and cost. Studies on fertilizer P compliance testing often lack recommendations on minimum P extractability threshold values. Here, thresholds are calculated based on actual fertilization efficiency of a large, chemically diverse set of recycled P fertilizers, many of which are already marketed. Thirty recycled P fertilizers were extracted with H2O, neutral ammonium citrate (NAC), electro-ultrafiltration (EUF), ferrihydrite-filled membranes (iron bag; IB), sodium bicarbonate (NaHCO3) and diffusive gradients in thin films (DGT). The mineral replacement value (MRV) of the fertilizer set was previously evaluated in three pot experiments at a fertilization rate of 50 mg kg−1 soil. MRV correlations with the extractions methods showed similar results for all besides H2O, which cannot be a reliable indicator for P availability. Fertilizers were classified as efficient or inefficient based on their MRV exceeding or falling below 60 % of the triple superphosphate reference value. The minimum P extractability threshold value (MPETV) for each method was based on the efficiency classification and it minimized the number of misclassified fertilizers. NAC, with a 60 % extractable minimum P threshold value, was the most adequate method for compliance testing, despite its overestimation of iron phosphate availability
Arctic migrating barnacle geese utilize accommodation fields in a new agricultural staging area
Full text linkThe recovery of threatened species after conservation measures can lead to human–wildlife conflicts. One example of such is the recent population growth of the Barnacle Goose Branta leucopsis, a large herbivorous bird. During migration, geese stage in large numbers on agricultural fields in range countries and cause substantial damage to farms. A combination of repelling fields, where geese were chased off by humans, and accommodation fields, which provide refuge sites for foraging geese, has been suggested as an effective management tool to mitigate conflicts.Using high-resolution satellite tracking data, we investigated habitat selection of 41 barnacle geese staging in Northern Karelia, Finland, during spring 2021. We estimated relative habitat use by these geese and conducted a fine-scale analysis of their use of different fields by employing Hidden Markov Models and integrated step-selection analysis. Fields included normal crop (no goose management), project and other (private and Nature 2000 area) accommodation fields and repelling fields. Project accommodation and repelling fields were established on areas known to have a long history of high grazing pressure by barnacle geese.We found that behavioural data of geese can be categorized into three different states (static, slow and fast movement). Static and slow states were used for local field selection, fast state for field selection in the regional area, and all states for field selection after leaving a repelling field.Overall, relative habitat use indicated that geese utilize accommodation fields more than expected by their availability. Integrated step-selection analyses revealed that geese avoided normal and repelling versus project accommodation fields at the regional scale. At the local scale, they preferred project accommodation fields over all other fields. After leaving a repelling field, geese did not show preference for any accommodation over repelling fields.Synthesis and application. Geese show individual selection for accommodation fields compared to normal or repelling fields across several scales. Our results suggest that the accommodation field concept—consisting of refuge areas and no-go areas where geese are repelled from—can help to mitigate the human–wildlife conflict using local stakeholders' knowledge.202
Report on scientific cod fishing and monitoring in 2023 in Åland, Finland
Full text linkAt present, Eastern Baltic cod (Gadus morhua) in the southern Baltic Sea grows slowly, shows low condition factor and is heavily infected by the larvae of liver worm (Contracaecum osculatum). It has been hypothesized that either the heavy infection by liver worms, lack of suitable food due to lack of oxygen in the deep bottoms of the Baltic Sea or both together cause severe problems for the cod. The final host of the liver worm is grey seal (Halichoerus grypus), and the worm is carried to cod via prey, smaller fish. There is a small-scale cod fishery in the Finnish waters in the Sea of Åland, where cod are large sized and in good condition. Grey seals are abundant in these waters.
In this study, the occurrence of Contracaecum larvae in the livers of cod especially in the Sea of Åland and the prey of the cod in the year 2023 were examined and presented together with the results from the years 2020, 2021, and 2022. The size of measured cod in 2023 varied from 30 to 118 cm (total length). Similarly, as in 2020–2022, the number of Contracaecum osculatum larvae on liver surface correlated with cod length. The Fulton’s condition factor of the cod in all years was high (1.01–1.13 in Åland). More importantly and similarly as in the previous years, the condition of the cod was not found to be in a statistically significant relation to the number of Contracaecum larvae on the liver surface nor the number of larvae per liver weight. The most common food items were Saduria and clupeid fish. The samples from all three years support the conclusion that when there is enough food for the cod, the effects of Contracaecum osculatum infection on the condition and growth of cod are small or even insignificant
Management Measures and Trends of Biological Invasions in Europe: A Survey‐Based Assessment of Local Managers
Full text linkBiological invasions are a major threat to biodiversity, ecosystem functioning and nature's contributions to people worldwide. However, the effectiveness of invasive alien species (IAS) management measures and the progress toward achieving biodiversity targets remain uncertain due to limited and nonuniform data availability. Management success is usually assessed at a local level and documented in technical reports, often written in languages other than English, which makes such data notoriously difficult to collect at large geographic scales. Here we present the first European assessment of how managers perceive trends in IAS and the effectiveness of management measures to mitigate biological invasions. We developed a structured questionnaire translated into 18 languages and disseminated it to local and regional managers of IAS in Europe. We received responses from 1928 participants from 41 European countries, including 24 European Union (EU) Member States. Our results reveal substantial efforts in IAS monitoring and control, with invasive plants being the primary focus. Yet, there is a general perception of an increase in the numbers, occupied areas, and impacts of IAS across environment and taxonomic groups, particularly plants, over time. This perceived increase is consistent across both EU and non-EU countries, with respondents from EU countries demonstrating more certainty in their responses. Our results also indicate a lack of data on alien vertebrates and invertebrates, reflecting a need for more targeted monitoring and knowledge sharing between managers and policymakers and between countries. Overall, our study suggests that Europe's current strategies are insufficient to substantially reduce IAS by 2030 and hence to meet the Kunming-Montreal Global Biodiversity Framework target